Still converting syntax highlighter spec.

This commit is contained in:
Simon Forman
2021-11-19 13:59:00 -08:00
parent 3f40e30c6f
commit a69b7e2a56
41 changed files with 1874 additions and 1874 deletions
@@ -96,15 +96,15 @@ R∘λ = λ∘R = R
</section>
<section id="implementation">
<h2>Implementation<a class="headerlink" href="#implementation" title="Permalink to this headline"></a></h2>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from functools import partial as curry
from itertools import product
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">functools</span> <span class="kn">import</span> <span class="n">partial</span> <span class="k">as</span> <span class="n">curry</span>
<span class="kn">from</span> <span class="nn">itertools</span> <span class="kn">import</span> <span class="n">product</span>
</pre></div>
</div>
<section id="and">
<h3><code class="docutils literal notranslate"><span class="pre">ϕ</span></code> and <code class="docutils literal notranslate"><span class="pre">λ</span></code><a class="headerlink" href="#and" title="Permalink to this headline"></a></h3>
<p>The empty set and the set of just the empty string.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>phi = frozenset() # ϕ
y = frozenset({&#39;&#39;}) # λ
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">phi</span> <span class="o">=</span> <span class="nb">frozenset</span><span class="p">()</span> <span class="c1"># ϕ</span>
<span class="n">y</span> <span class="o">=</span> <span class="nb">frozenset</span><span class="p">({</span><span class="s1">&#39;&#39;</span><span class="p">})</span> <span class="c1"># λ</span>
</pre></div>
</div>
</section>
@@ -115,7 +115,7 @@ illustrate the algorithm and because you can represent any other
alphabet with two symbols (if you had to.)</p>
<p>I chose the names <code class="docutils literal notranslate"><span class="pre">O</span></code> and <code class="docutils literal notranslate"><span class="pre">l</span></code> (uppercase “o” and lowercase “L”) to
look like <code class="docutils literal notranslate"><span class="pre">0</span></code> and <code class="docutils literal notranslate"><span class="pre">1</span></code> (zero and one) respectively.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>syms = O, l = frozenset({&#39;0&#39;}), frozenset({&#39;1&#39;})
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">syms</span> <span class="o">=</span> <span class="n">O</span><span class="p">,</span> <span class="n">l</span> <span class="o">=</span> <span class="nb">frozenset</span><span class="p">({</span><span class="s1">&#39;0&#39;</span><span class="p">}),</span> <span class="nb">frozenset</span><span class="p">({</span><span class="s1">&#39;1&#39;</span><span class="p">})</span>
</pre></div>
</div>
</section>
@@ -133,7 +133,7 @@ expression</em> is one of:</p>
</pre></div>
</div>
<p>Where <code class="docutils literal notranslate"><span class="pre">R</span></code> and <code class="docutils literal notranslate"><span class="pre">S</span></code> stand for <em>regular expressions</em>.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>AND, CONS, KSTAR, NOT, OR = &#39;and cons * not or&#39;.split() # Tags are just strings.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">AND</span><span class="p">,</span> <span class="n">CONS</span><span class="p">,</span> <span class="n">KSTAR</span><span class="p">,</span> <span class="n">NOT</span><span class="p">,</span> <span class="n">OR</span> <span class="o">=</span> <span class="s1">&#39;and cons * not or&#39;</span><span class="o">.</span><span class="n">split</span><span class="p">()</span> <span class="c1"># Tags are just strings.</span>
</pre></div>
</div>
<p>Because they are formed of <code class="docutils literal notranslate"><span class="pre">frozenset</span></code>, <code class="docutils literal notranslate"><span class="pre">tuple</span></code> and <code class="docutils literal notranslate"><span class="pre">str</span></code> objects
@@ -141,36 +141,36 @@ only, these datastructures are immutable.</p>
</section>
<section id="string-representation-of-re-datastructures">
<h3>String Representation of RE Datastructures<a class="headerlink" href="#string-representation-of-re-datastructures" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def stringy(re):
&#39;&#39;&#39;
Return a nice string repr for a regular expression datastructure.
&#39;&#39;&#39;
if re == I: return &#39;.&#39;
if re in syms: return next(iter(re))
if re == y: return &#39;^&#39;
if re == phi: return &#39;X&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">stringy</span><span class="p">(</span><span class="n">re</span><span class="p">):</span>
<span class="sd">&#39;&#39;&#39;</span>
<span class="sd"> Return a nice string repr for a regular expression datastructure.</span>
<span class="sd"> &#39;&#39;&#39;</span>
<span class="k">if</span> <span class="n">re</span> <span class="o">==</span> <span class="n">I</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;.&#39;</span>
<span class="k">if</span> <span class="n">re</span> <span class="ow">in</span> <span class="n">syms</span><span class="p">:</span> <span class="k">return</span> <span class="nb">next</span><span class="p">(</span><span class="nb">iter</span><span class="p">(</span><span class="n">re</span><span class="p">))</span>
<span class="k">if</span> <span class="n">re</span> <span class="o">==</span> <span class="n">y</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;^&#39;</span>
<span class="k">if</span> <span class="n">re</span> <span class="o">==</span> <span class="n">phi</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;X&#39;</span>
assert isinstance(re, tuple), repr(re)
tag = re[0]
<span class="k">assert</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">re</span><span class="p">,</span> <span class="nb">tuple</span><span class="p">),</span> <span class="nb">repr</span><span class="p">(</span><span class="n">re</span><span class="p">)</span>
<span class="n">tag</span> <span class="o">=</span> <span class="n">re</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
if tag == KSTAR:
body = stringy(re[1])
if not body: return body
if len(body) &gt; 1: return &#39;(&#39; + body + &quot;)*&quot;
return body + &#39;*&#39;
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">KSTAR</span><span class="p">:</span>
<span class="n">body</span> <span class="o">=</span> <span class="n">stringy</span><span class="p">(</span><span class="n">re</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">body</span><span class="p">:</span> <span class="k">return</span> <span class="n">body</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">body</span><span class="p">)</span> <span class="o">&gt;</span> <span class="mi">1</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;(&#39;</span> <span class="o">+</span> <span class="n">body</span> <span class="o">+</span> <span class="s2">&quot;)*&quot;</span>
<span class="k">return</span> <span class="n">body</span> <span class="o">+</span> <span class="s1">&#39;*&#39;</span>
if tag == NOT:
body = stringy(re[1])
if not body: return body
if len(body) &gt; 1: return &#39;(&#39; + body + &quot;)&#39;&quot;
return body + &quot;&#39;&quot;
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">NOT</span><span class="p">:</span>
<span class="n">body</span> <span class="o">=</span> <span class="n">stringy</span><span class="p">(</span><span class="n">re</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">body</span><span class="p">:</span> <span class="k">return</span> <span class="n">body</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">body</span><span class="p">)</span> <span class="o">&gt;</span> <span class="mi">1</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;(&#39;</span> <span class="o">+</span> <span class="n">body</span> <span class="o">+</span> <span class="s2">&quot;)&#39;&quot;</span>
<span class="k">return</span> <span class="n">body</span> <span class="o">+</span> <span class="s2">&quot;&#39;&quot;</span>
r, s = stringy(re[1]), stringy(re[2])
if tag == CONS: return r + s
if tag == OR: return &#39;%s | %s&#39; % (r, s)
if tag == AND: return &#39;(%s) &amp; (%s)&#39; % (r, s)
<span class="n">r</span><span class="p">,</span> <span class="n">s</span> <span class="o">=</span> <span class="n">stringy</span><span class="p">(</span><span class="n">re</span><span class="p">[</span><span class="mi">1</span><span class="p">]),</span> <span class="n">stringy</span><span class="p">(</span><span class="n">re</span><span class="p">[</span><span class="mi">2</span><span class="p">])</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">CONS</span><span class="p">:</span> <span class="k">return</span> <span class="n">r</span> <span class="o">+</span> <span class="n">s</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">OR</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;</span><span class="si">%s</span><span class="s1"> | </span><span class="si">%s</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="p">(</span><span class="n">r</span><span class="p">,</span> <span class="n">s</span><span class="p">)</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">AND</span><span class="p">:</span> <span class="k">return</span> <span class="s1">&#39;(</span><span class="si">%s</span><span class="s1">) &amp; (</span><span class="si">%s</span><span class="s1">)&#39;</span> <span class="o">%</span> <span class="p">(</span><span class="n">r</span><span class="p">,</span> <span class="n">s</span><span class="p">)</span>
raise ValueError
<span class="k">raise</span> <span class="ne">ValueError</span>
</pre></div>
</div>
</section>
@@ -180,10 +180,10 @@ only, these datastructures are immutable.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">I</span> <span class="o">=</span> <span class="p">(</span><span class="mi">0</span><span class="o">|</span><span class="mi">1</span><span class="p">)</span><span class="o">*</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>I = (KSTAR, (OR, O, l))
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">I</span> <span class="o">=</span> <span class="p">(</span><span class="n">KSTAR</span><span class="p">,</span> <span class="p">(</span><span class="n">OR</span><span class="p">,</span> <span class="n">O</span><span class="p">,</span> <span class="n">l</span><span class="p">))</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>print stringy(I)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="nb">print</span> <span class="n">stringy</span><span class="p">(</span><span class="n">I</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="o">.</span>
@@ -198,13 +198,13 @@ only, these datastructures are immutable.</p>
</pre></div>
</div>
<p>Note that it contains one of everything.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>a = (CONS, I, (CONS, l, (CONS, l, (CONS, l, I))))
b = (CONS, I, (CONS, O, l))
c = (CONS, l, (KSTAR, l))
it = (AND, a, (NOT, (OR, b, c)))
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">a</span> <span class="o">=</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">I</span><span class="p">,</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">l</span><span class="p">,</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">l</span><span class="p">,</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">l</span><span class="p">,</span> <span class="n">I</span><span class="p">))))</span>
<span class="n">b</span> <span class="o">=</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">I</span><span class="p">,</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">O</span><span class="p">,</span> <span class="n">l</span><span class="p">))</span>
<span class="n">c</span> <span class="o">=</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">l</span><span class="p">,</span> <span class="p">(</span><span class="n">KSTAR</span><span class="p">,</span> <span class="n">l</span><span class="p">))</span>
<span class="n">it</span> <span class="o">=</span> <span class="p">(</span><span class="n">AND</span><span class="p">,</span> <span class="n">a</span><span class="p">,</span> <span class="p">(</span><span class="n">NOT</span><span class="p">,</span> <span class="p">(</span><span class="n">OR</span><span class="p">,</span> <span class="n">b</span><span class="p">,</span> <span class="n">c</span><span class="p">)))</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>print stringy(it)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="nb">print</span> <span class="n">stringy</span><span class="p">(</span><span class="n">it</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">(</span><span class="o">.</span><span class="mf">111.</span><span class="p">)</span> <span class="o">&amp;</span> <span class="p">((</span><span class="o">.</span><span class="mi">01</span> <span class="o">|</span> <span class="mi">11</span><span class="o">*</span><span class="p">)</span><span class="s1">&#39;)</span>
@@ -214,36 +214,36 @@ it = (AND, a, (NOT, (OR, b, c)))
<section id="nully">
<h3><code class="docutils literal notranslate"><span class="pre">nully()</span></code><a class="headerlink" href="#nully" title="Permalink to this headline"></a></h3>
<p>Lets get that auxiliary predicate function <code class="docutils literal notranslate"><span class="pre">δ</span></code> out of the way.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def nully(R):
&#39;&#39;&#39;
δ - Return λ if λ ⊆ R otherwise ϕ.
&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">nully</span><span class="p">(</span><span class="n">R</span><span class="p">):</span>
<span class="sd">&#39;&#39;&#39;</span>
<span class="sd"> δ - Return λ if λ ⊆ R otherwise ϕ.</span>
<span class="sd"> &#39;&#39;&#39;</span>
# δ(a) → ϕ
# δ(ϕ) → ϕ
if R in syms or R == phi:
return phi
<span class="c1"># δ(a) → ϕ</span>
<span class="c1"># δ(ϕ) → ϕ</span>
<span class="k">if</span> <span class="n">R</span> <span class="ow">in</span> <span class="n">syms</span> <span class="ow">or</span> <span class="n">R</span> <span class="o">==</span> <span class="n">phi</span><span class="p">:</span>
<span class="k">return</span> <span class="n">phi</span>
# δ(λ) → λ
if R == y:
return y
<span class="c1"># δ(λ) → λ</span>
<span class="k">if</span> <span class="n">R</span> <span class="o">==</span> <span class="n">y</span><span class="p">:</span>
<span class="k">return</span> <span class="n">y</span>
tag = R[0]
<span class="n">tag</span> <span class="o">=</span> <span class="n">R</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
# δ(R*) → λ
if tag == KSTAR:
return y
<span class="c1"># δ(R*) → λ</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">KSTAR</span><span class="p">:</span>
<span class="k">return</span> <span class="n">y</span>
# δ(¬R) δ(R)≟ϕ → λ
# δ(¬R) δ(R)≟λ → ϕ
if tag == NOT:
return phi if nully(R[1]) else y
<span class="c1"># δ(¬R) δ(R)≟ϕ → λ</span>
<span class="c1"># δ(¬R) δ(R)≟λ → ϕ</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">NOT</span><span class="p">:</span>
<span class="k">return</span> <span class="n">phi</span> <span class="k">if</span> <span class="n">nully</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">])</span> <span class="k">else</span> <span class="n">y</span>
# δ(R∘S) → δ(R) ∧ δ(S)
# δ(R ∧ S) → δ(R) ∧ δ(S)
# δ(R S) → δ(R) δ(S)
r, s = nully(R[1]), nully(R[2])
return r &amp; s if tag in {AND, CONS} else r | s
<span class="c1"># δ(R∘S) → δ(R) ∧ δ(S)</span>
<span class="c1"># δ(R ∧ S) → δ(R) ∧ δ(S)</span>
<span class="c1"># δ(R S) → δ(R) δ(S)</span>
<span class="n">r</span><span class="p">,</span> <span class="n">s</span> <span class="o">=</span> <span class="n">nully</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">]),</span> <span class="n">nully</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">2</span><span class="p">])</span>
<span class="k">return</span> <span class="n">r</span> <span class="o">&amp;</span> <span class="n">s</span> <span class="k">if</span> <span class="n">tag</span> <span class="ow">in</span> <span class="p">{</span><span class="n">AND</span><span class="p">,</span> <span class="n">CONS</span><span class="p">}</span> <span class="k">else</span> <span class="n">r</span> <span class="o">|</span> <span class="n">s</span>
</pre></div>
</div>
</section>
@@ -252,71 +252,71 @@ it = (AND, a, (NOT, (OR, b, c)))
<p>This is the straightforward version with no “compaction”. It works fine,
but does waaaay too much work because the expressions grow each
derivation.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def D(symbol):
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">D</span><span class="p">(</span><span class="n">symbol</span><span class="p">):</span>
def derv(R):
<span class="k">def</span> <span class="nf">derv</span><span class="p">(</span><span class="n">R</span><span class="p">):</span>
# ∂a(a) → λ
if R == {symbol}:
return y
<span class="c1"># ∂a(a) → λ</span>
<span class="k">if</span> <span class="n">R</span> <span class="o">==</span> <span class="p">{</span><span class="n">symbol</span><span class="p">}:</span>
<span class="k">return</span> <span class="n">y</span>
# ∂a(λ) → ϕ
# ∂a(ϕ) → ϕ
# ∂a(¬a) → ϕ
if R == y or R == phi or R in syms:
return phi
<span class="c1"># ∂a(λ) → ϕ</span>
<span class="c1"># ∂a(ϕ) → ϕ</span>
<span class="c1"># ∂a(¬a) → ϕ</span>
<span class="k">if</span> <span class="n">R</span> <span class="o">==</span> <span class="n">y</span> <span class="ow">or</span> <span class="n">R</span> <span class="o">==</span> <span class="n">phi</span> <span class="ow">or</span> <span class="n">R</span> <span class="ow">in</span> <span class="n">syms</span><span class="p">:</span>
<span class="k">return</span> <span class="n">phi</span>
tag = R[0]
<span class="n">tag</span> <span class="o">=</span> <span class="n">R</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
# ∂a(R*) → ∂a(R)∘R*
if tag == KSTAR:
return (CONS, derv(R[1]), R)
<span class="c1"># ∂a(R*) → ∂a(R)∘R*</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">KSTAR</span><span class="p">:</span>
<span class="k">return</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">]),</span> <span class="n">R</span><span class="p">)</span>
# ∂a(¬R) → ¬∂a(R)
if tag == NOT:
return (NOT, derv(R[1]))
<span class="c1"># ∂a(¬R) → ¬∂a(R)</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">NOT</span><span class="p">:</span>
<span class="k">return</span> <span class="p">(</span><span class="n">NOT</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">]))</span>
r, s = R[1:]
<span class="n">r</span><span class="p">,</span> <span class="n">s</span> <span class="o">=</span> <span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">:]</span>
# ∂a(R∘S) → ∂a(R)∘S δ(R)∘∂a(S)
if tag == CONS:
A = (CONS, derv(r), s) # A = ∂a(R)∘S
# A δ(R) ∘ ∂a(S)
# A λ ∘ ∂a(S) → A ∂a(S)
# A ϕ ∘ ∂a(S) → A ∨ ϕ → A
return (OR, A, derv(s)) if nully(r) else A
<span class="c1"># ∂a(R∘S) → ∂a(R)∘S δ(R)∘∂a(S)</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">CONS</span><span class="p">:</span>
<span class="n">A</span> <span class="o">=</span> <span class="p">(</span><span class="n">CONS</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">r</span><span class="p">),</span> <span class="n">s</span><span class="p">)</span> <span class="c1"># A = ∂a(R)∘S</span>
<span class="c1"># A δ(R) ∘ ∂a(S)</span>
<span class="c1"># A λ ∘ ∂a(S) → A ∂a(S)</span>
<span class="c1"># A ϕ ∘ ∂a(S) → A ∨ ϕ → A</span>
<span class="k">return</span> <span class="p">(</span><span class="n">OR</span><span class="p">,</span> <span class="n">A</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">s</span><span class="p">))</span> <span class="k">if</span> <span class="n">nully</span><span class="p">(</span><span class="n">r</span><span class="p">)</span> <span class="k">else</span> <span class="n">A</span>
# ∂a(R ∧ S) → ∂a(R) ∧ ∂a(S)
# ∂a(R S) → ∂a(R) ∂a(S)
return (tag, derv(r), derv(s))
<span class="c1"># ∂a(R ∧ S) → ∂a(R) ∧ ∂a(S)</span>
<span class="c1"># ∂a(R S) → ∂a(R) ∂a(S)</span>
<span class="k">return</span> <span class="p">(</span><span class="n">tag</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">r</span><span class="p">),</span> <span class="n">derv</span><span class="p">(</span><span class="n">s</span><span class="p">))</span>
return derv
<span class="k">return</span> <span class="n">derv</span>
</pre></div>
</div>
</section>
<section id="compaction-rules">
<h3>Compaction Rules<a class="headerlink" href="#compaction-rules" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def _compaction_rule(relation, one, zero, a, b):
return (
b if a == one else # R*1 = 1*R = R
a if b == one else
zero if a == zero or b == zero else # R*0 = 0*R = 0
(relation, a, b)
)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">_compaction_rule</span><span class="p">(</span><span class="n">relation</span><span class="p">,</span> <span class="n">one</span><span class="p">,</span> <span class="n">zero</span><span class="p">,</span> <span class="n">a</span><span class="p">,</span> <span class="n">b</span><span class="p">):</span>
<span class="k">return</span> <span class="p">(</span>
<span class="n">b</span> <span class="k">if</span> <span class="n">a</span> <span class="o">==</span> <span class="n">one</span> <span class="k">else</span> <span class="c1"># R*1 = 1*R = R</span>
<span class="n">a</span> <span class="k">if</span> <span class="n">b</span> <span class="o">==</span> <span class="n">one</span> <span class="k">else</span>
<span class="n">zero</span> <span class="k">if</span> <span class="n">a</span> <span class="o">==</span> <span class="n">zero</span> <span class="ow">or</span> <span class="n">b</span> <span class="o">==</span> <span class="n">zero</span> <span class="k">else</span> <span class="c1"># R*0 = 0*R = 0</span>
<span class="p">(</span><span class="n">relation</span><span class="p">,</span> <span class="n">a</span><span class="p">,</span> <span class="n">b</span><span class="p">)</span>
<span class="p">)</span>
</pre></div>
</div>
<p>An elegant symmetry.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span># R ∧ I = I ∧ R = R
# R ∧ ϕ = ϕ ∧ R = ϕ
_and = curry(_compaction_rule, AND, I, phi)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="c1"># R ∧ I = I ∧ R = R</span>
<span class="c1"># R ∧ ϕ = ϕ ∧ R = ϕ</span>
<span class="n">_and</span> <span class="o">=</span> <span class="n">curry</span><span class="p">(</span><span class="n">_compaction_rule</span><span class="p">,</span> <span class="n">AND</span><span class="p">,</span> <span class="n">I</span><span class="p">,</span> <span class="n">phi</span><span class="p">)</span>
# R ϕ = ϕ R = R
# R I = I R = I
_or = curry(_compaction_rule, OR, phi, I)
<span class="c1"># R ϕ = ϕ R = R</span>
<span class="c1"># R I = I R = I</span>
<span class="n">_or</span> <span class="o">=</span> <span class="n">curry</span><span class="p">(</span><span class="n">_compaction_rule</span><span class="p">,</span> <span class="n">OR</span><span class="p">,</span> <span class="n">phi</span><span class="p">,</span> <span class="n">I</span><span class="p">)</span>
# R∘λ = λ∘R = R
# R∘ϕ = ϕ∘R = ϕ
_cons = curry(_compaction_rule, CONS, y, phi)
<span class="c1"># R∘λ = λ∘R = R</span>
<span class="c1"># R∘ϕ = ϕ∘R = ϕ</span>
<span class="n">_cons</span> <span class="o">=</span> <span class="n">curry</span><span class="p">(</span><span class="n">_compaction_rule</span><span class="p">,</span> <span class="n">CONS</span><span class="p">,</span> <span class="n">y</span><span class="p">,</span> <span class="n">phi</span><span class="p">)</span>
</pre></div>
</div>
</section>
@@ -325,21 +325,21 @@ _cons = curry(_compaction_rule, CONS, y, phi)
<p>We can save re-processing by remembering results we have already
computed. RE datastructures are immutable and the <code class="docutils literal notranslate"><span class="pre">derv()</span></code> functions
are <em>pure</em> so this is fine.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>class Memo(object):
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">Memo</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
def __init__(self, f):
self.f = f
self.calls = self.hits = 0
self.mem = {}
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">f</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">f</span> <span class="o">=</span> <span class="n">f</span>
<span class="bp">self</span><span class="o">.</span><span class="n">calls</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">hits</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">mem</span> <span class="o">=</span> <span class="p">{}</span>
def __call__(self, key):
self.calls += 1
try:
result = self.mem[key]
self.hits += 1
except KeyError:
result = self.mem[key] = self.f(key)
return result
<span class="k">def</span> <span class="fm">__call__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">key</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">calls</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">result</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">mem</span><span class="p">[</span><span class="n">key</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">hits</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">except</span> <span class="ne">KeyError</span><span class="p">:</span>
<span class="n">result</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">mem</span><span class="p">[</span><span class="n">key</span><span class="p">]</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">f</span><span class="p">(</span><span class="n">key</span><span class="p">)</span>
<span class="k">return</span> <span class="n">result</span>
</pre></div>
</div>
</section>
@@ -347,47 +347,47 @@ are <em>pure</em> so this is fine.</p>
<h3>With “Compaction”<a class="headerlink" href="#with-compaction" title="Permalink to this headline"></a></h3>
<p>This version uses the rules above to perform compaction. It keeps the
expressions from growing too large.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def D_compaction(symbol):
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">D_compaction</span><span class="p">(</span><span class="n">symbol</span><span class="p">):</span>
@Memo
def derv(R):
<span class="nd">@Memo</span>
<span class="k">def</span> <span class="nf">derv</span><span class="p">(</span><span class="n">R</span><span class="p">):</span>
# ∂a(a) → λ
if R == {symbol}:
return y
<span class="c1"># ∂a(a) → λ</span>
<span class="k">if</span> <span class="n">R</span> <span class="o">==</span> <span class="p">{</span><span class="n">symbol</span><span class="p">}:</span>
<span class="k">return</span> <span class="n">y</span>
# ∂a(λ) → ϕ
# ∂a(ϕ) → ϕ
# ∂a(¬a) → ϕ
if R == y or R == phi or R in syms:
return phi
<span class="c1"># ∂a(λ) → ϕ</span>
<span class="c1"># ∂a(ϕ) → ϕ</span>
<span class="c1"># ∂a(¬a) → ϕ</span>
<span class="k">if</span> <span class="n">R</span> <span class="o">==</span> <span class="n">y</span> <span class="ow">or</span> <span class="n">R</span> <span class="o">==</span> <span class="n">phi</span> <span class="ow">or</span> <span class="n">R</span> <span class="ow">in</span> <span class="n">syms</span><span class="p">:</span>
<span class="k">return</span> <span class="n">phi</span>
tag = R[0]
<span class="n">tag</span> <span class="o">=</span> <span class="n">R</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
# ∂a(R*) → ∂a(R)∘R*
if tag == KSTAR:
return _cons(derv(R[1]), R)
<span class="c1"># ∂a(R*) → ∂a(R)∘R*</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">KSTAR</span><span class="p">:</span>
<span class="k">return</span> <span class="n">_cons</span><span class="p">(</span><span class="n">derv</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">]),</span> <span class="n">R</span><span class="p">)</span>
# ∂a(¬R) → ¬∂a(R)
if tag == NOT:
return (NOT, derv(R[1]))
<span class="c1"># ∂a(¬R) → ¬∂a(R)</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">NOT</span><span class="p">:</span>
<span class="k">return</span> <span class="p">(</span><span class="n">NOT</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">]))</span>
r, s = R[1:]
<span class="n">r</span><span class="p">,</span> <span class="n">s</span> <span class="o">=</span> <span class="n">R</span><span class="p">[</span><span class="mi">1</span><span class="p">:]</span>
# ∂a(R∘S) → ∂a(R)∘S δ(R)∘∂a(S)
if tag == CONS:
A = _cons(derv(r), s) # A = ∂a(r)∘s
# A δ(R) ∘ ∂a(S)
# A λ ∘ ∂a(S) → A ∂a(S)
# A ϕ ∘ ∂a(S) → A ∨ ϕ → A
return _or(A, derv(s)) if nully(r) else A
<span class="c1"># ∂a(R∘S) → ∂a(R)∘S δ(R)∘∂a(S)</span>
<span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">CONS</span><span class="p">:</span>
<span class="n">A</span> <span class="o">=</span> <span class="n">_cons</span><span class="p">(</span><span class="n">derv</span><span class="p">(</span><span class="n">r</span><span class="p">),</span> <span class="n">s</span><span class="p">)</span> <span class="c1"># A = ∂a(r)∘s</span>
<span class="c1"># A δ(R) ∘ ∂a(S)</span>
<span class="c1"># A λ ∘ ∂a(S) → A ∂a(S)</span>
<span class="c1"># A ϕ ∘ ∂a(S) → A ∨ ϕ → A</span>
<span class="k">return</span> <span class="n">_or</span><span class="p">(</span><span class="n">A</span><span class="p">,</span> <span class="n">derv</span><span class="p">(</span><span class="n">s</span><span class="p">))</span> <span class="k">if</span> <span class="n">nully</span><span class="p">(</span><span class="n">r</span><span class="p">)</span> <span class="k">else</span> <span class="n">A</span>
# ∂a(R ∧ S) → ∂a(R) ∧ ∂a(S)
# ∂a(R S) → ∂a(R) ∂a(S)
dr, ds = derv(r), derv(s)
return _and(dr, ds) if tag == AND else _or(dr, ds)
<span class="c1"># ∂a(R ∧ S) → ∂a(R) ∧ ∂a(S)</span>
<span class="c1"># ∂a(R S) → ∂a(R) ∂a(S)</span>
<span class="n">dr</span><span class="p">,</span> <span class="n">ds</span> <span class="o">=</span> <span class="n">derv</span><span class="p">(</span><span class="n">r</span><span class="p">),</span> <span class="n">derv</span><span class="p">(</span><span class="n">s</span><span class="p">)</span>
<span class="k">return</span> <span class="n">_and</span><span class="p">(</span><span class="n">dr</span><span class="p">,</span> <span class="n">ds</span><span class="p">)</span> <span class="k">if</span> <span class="n">tag</span> <span class="o">==</span> <span class="n">AND</span> <span class="k">else</span> <span class="n">_or</span><span class="p">(</span><span class="n">dr</span><span class="p">,</span> <span class="n">ds</span><span class="p">)</span>
return derv
<span class="k">return</span> <span class="n">derv</span>
</pre></div>
</div>
</section>
@@ -395,26 +395,26 @@ expressions from growing too large.</p>
<section id="lets-try-it-out">
<h2>Lets try it out…<a class="headerlink" href="#lets-try-it-out" title="Permalink to this headline"></a></h2>
<p>(FIXME: redo.)</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>o, z = D_compaction(&#39;0&#39;), D_compaction(&#39;1&#39;)
REs = set()
N = 5
names = list(product(*(N * [(0, 1)])))
dervs = list(product(*(N * [(o, z)])))
for name, ds in zip(names, dervs):
R = it
ds = list(ds)
while ds:
R = ds.pop()(R)
if R == phi or R == I:
break
REs.add(R)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">o</span><span class="p">,</span> <span class="n">z</span> <span class="o">=</span> <span class="n">D_compaction</span><span class="p">(</span><span class="s1">&#39;0&#39;</span><span class="p">),</span> <span class="n">D_compaction</span><span class="p">(</span><span class="s1">&#39;1&#39;</span><span class="p">)</span>
<span class="n">REs</span> <span class="o">=</span> <span class="nb">set</span><span class="p">()</span>
<span class="n">N</span> <span class="o">=</span> <span class="mi">5</span>
<span class="n">names</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">product</span><span class="p">(</span><span class="o">*</span><span class="p">(</span><span class="n">N</span> <span class="o">*</span> <span class="p">[(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">)])))</span>
<span class="n">dervs</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">product</span><span class="p">(</span><span class="o">*</span><span class="p">(</span><span class="n">N</span> <span class="o">*</span> <span class="p">[(</span><span class="n">o</span><span class="p">,</span> <span class="n">z</span><span class="p">)])))</span>
<span class="k">for</span> <span class="n">name</span><span class="p">,</span> <span class="n">ds</span> <span class="ow">in</span> <span class="nb">zip</span><span class="p">(</span><span class="n">names</span><span class="p">,</span> <span class="n">dervs</span><span class="p">):</span>
<span class="n">R</span> <span class="o">=</span> <span class="n">it</span>
<span class="n">ds</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">ds</span><span class="p">)</span>
<span class="k">while</span> <span class="n">ds</span><span class="p">:</span>
<span class="n">R</span> <span class="o">=</span> <span class="n">ds</span><span class="o">.</span><span class="n">pop</span><span class="p">()(</span><span class="n">R</span><span class="p">)</span>
<span class="k">if</span> <span class="n">R</span> <span class="o">==</span> <span class="n">phi</span> <span class="ow">or</span> <span class="n">R</span> <span class="o">==</span> <span class="n">I</span><span class="p">:</span>
<span class="k">break</span>
<span class="n">REs</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">R</span><span class="p">)</span>
print stringy(it) ; print
print o.hits, &#39;/&#39;, o.calls
print z.hits, &#39;/&#39;, z.calls
print
for s in sorted(map(stringy, REs), key=lambda n: (len(n), n)):
print s
<span class="nb">print</span> <span class="n">stringy</span><span class="p">(</span><span class="n">it</span><span class="p">)</span> <span class="p">;</span> <span class="nb">print</span>
<span class="nb">print</span> <span class="n">o</span><span class="o">.</span><span class="n">hits</span><span class="p">,</span> <span class="s1">&#39;/&#39;</span><span class="p">,</span> <span class="n">o</span><span class="o">.</span><span class="n">calls</span>
<span class="nb">print</span> <span class="n">z</span><span class="o">.</span><span class="n">hits</span><span class="p">,</span> <span class="s1">&#39;/&#39;</span><span class="p">,</span> <span class="n">z</span><span class="o">.</span><span class="n">calls</span>
<span class="nb">print</span>
<span class="k">for</span> <span class="n">s</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="nb">map</span><span class="p">(</span><span class="n">stringy</span><span class="p">,</span> <span class="n">REs</span><span class="p">),</span> <span class="n">key</span><span class="o">=</span><span class="k">lambda</span> <span class="n">n</span><span class="p">:</span> <span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">n</span><span class="p">),</span> <span class="n">n</span><span class="p">)):</span>
<span class="nb">print</span> <span class="n">s</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">(</span><span class="o">.</span><span class="mf">111.</span><span class="p">)</span> <span class="o">&amp;</span> <span class="p">((</span><span class="o">.</span><span class="mi">01</span> <span class="o">|</span> <span class="mi">11</span><span class="o">*</span><span class="p">)</span><span class="s1">&#39;)</span>
@@ -555,45 +555,45 @@ a --1--&gt; ∂1(a)
<p>You can see the one-way nature of the <code class="docutils literal notranslate"><span class="pre">g</span></code> state and the <code class="docutils literal notranslate"><span class="pre">hij</span></code> “trap”
in the way that the <code class="docutils literal notranslate"><span class="pre">.111.</span></code> on the left-hand side of the <code class="docutils literal notranslate"><span class="pre">&amp;</span></code>
disappears once it has been matched.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from collections import defaultdict
from pprint import pprint
from string import ascii_lowercase
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">collections</span> <span class="kn">import</span> <span class="n">defaultdict</span>
<span class="kn">from</span> <span class="nn">pprint</span> <span class="kn">import</span> <span class="n">pprint</span>
<span class="kn">from</span> <span class="nn">string</span> <span class="kn">import</span> <span class="n">ascii_lowercase</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>d0, d1 = D_compaction(&#39;0&#39;), D_compaction(&#39;1&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">d0</span><span class="p">,</span> <span class="n">d1</span> <span class="o">=</span> <span class="n">D_compaction</span><span class="p">(</span><span class="s1">&#39;0&#39;</span><span class="p">),</span> <span class="n">D_compaction</span><span class="p">(</span><span class="s1">&#39;1&#39;</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="explore">
<h3><code class="docutils literal notranslate"><span class="pre">explore()</span></code><a class="headerlink" href="#explore" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def explore(re):
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">explore</span><span class="p">(</span><span class="n">re</span><span class="p">):</span>
# Don&#39;t have more than 26 states...
names = defaultdict(iter(ascii_lowercase).next)
<span class="c1"># Don&#39;t have more than 26 states...</span>
<span class="n">names</span> <span class="o">=</span> <span class="n">defaultdict</span><span class="p">(</span><span class="nb">iter</span><span class="p">(</span><span class="n">ascii_lowercase</span><span class="p">)</span><span class="o">.</span><span class="n">next</span><span class="p">)</span>
table, accepting = dict(), set()
<span class="n">table</span><span class="p">,</span> <span class="n">accepting</span> <span class="o">=</span> <span class="nb">dict</span><span class="p">(),</span> <span class="nb">set</span><span class="p">()</span>
to_check = {re}
while to_check:
<span class="n">to_check</span> <span class="o">=</span> <span class="p">{</span><span class="n">re</span><span class="p">}</span>
<span class="k">while</span> <span class="n">to_check</span><span class="p">:</span>
re = to_check.pop()
state_name = names[re]
<span class="n">re</span> <span class="o">=</span> <span class="n">to_check</span><span class="o">.</span><span class="n">pop</span><span class="p">()</span>
<span class="n">state_name</span> <span class="o">=</span> <span class="n">names</span><span class="p">[</span><span class="n">re</span><span class="p">]</span>
if (state_name, 0) in table:
continue
<span class="k">if</span> <span class="p">(</span><span class="n">state_name</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span> <span class="ow">in</span> <span class="n">table</span><span class="p">:</span>
<span class="k">continue</span>
if nully(re):
accepting.add(state_name)
<span class="k">if</span> <span class="n">nully</span><span class="p">(</span><span class="n">re</span><span class="p">):</span>
<span class="n">accepting</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">state_name</span><span class="p">)</span>
o, i = d0(re), d1(re)
table[state_name, 0] = names[o] ; to_check.add(o)
table[state_name, 1] = names[i] ; to_check.add(i)
<span class="n">o</span><span class="p">,</span> <span class="n">i</span> <span class="o">=</span> <span class="n">d0</span><span class="p">(</span><span class="n">re</span><span class="p">),</span> <span class="n">d1</span><span class="p">(</span><span class="n">re</span><span class="p">)</span>
<span class="n">table</span><span class="p">[</span><span class="n">state_name</span><span class="p">,</span> <span class="mi">0</span><span class="p">]</span> <span class="o">=</span> <span class="n">names</span><span class="p">[</span><span class="n">o</span><span class="p">]</span> <span class="p">;</span> <span class="n">to_check</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">o</span><span class="p">)</span>
<span class="n">table</span><span class="p">[</span><span class="n">state_name</span><span class="p">,</span> <span class="mi">1</span><span class="p">]</span> <span class="o">=</span> <span class="n">names</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="p">;</span> <span class="n">to_check</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">i</span><span class="p">)</span>
return table, accepting
<span class="k">return</span> <span class="n">table</span><span class="p">,</span> <span class="n">accepting</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>table, accepting = explore(it)
table
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">table</span><span class="p">,</span> <span class="n">accepting</span> <span class="o">=</span> <span class="n">explore</span><span class="p">(</span><span class="n">it</span><span class="p">)</span>
<span class="n">table</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">{(</span><span class="s1">&#39;a&#39;</span><span class="p">,</span> <span class="mi">0</span><span class="p">):</span> <span class="s1">&#39;b&#39;</span><span class="p">,</span>
@@ -618,7 +618,7 @@ table
<span class="p">(</span><span class="s1">&#39;j&#39;</span><span class="p">,</span> <span class="mi">1</span><span class="p">):</span> <span class="s1">&#39;h&#39;</span><span class="p">}</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>accepting
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">accepting</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">{</span><span class="s1">&#39;h&#39;</span><span class="p">,</span> <span class="s1">&#39;i&#39;</span><span class="p">}</span>
@@ -629,31 +629,31 @@ table
<h3>Generate Diagram<a class="headerlink" href="#generate-diagram" title="Permalink to this headline"></a></h3>
<p>Once we have the FSM table and the set of accepting states we can
generate the diagram above.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>_template = &#39;&#39;&#39;\
digraph finite_state_machine {
rankdir=LR;
size=&quot;8,5&quot;
node [shape = doublecircle]; %s;
node [shape = circle];
%s
}
&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">_template</span> <span class="o">=</span> <span class="s1">&#39;&#39;&#39;</span><span class="se">\</span>
<span class="s1">digraph finite_state_machine {</span>
<span class="s1"> rankdir=LR;</span>
<span class="s1"> size=&quot;8,5&quot;</span>
<span class="s1"> node [shape = doublecircle]; </span><span class="si">%s</span><span class="s1">;</span>
<span class="s1"> node [shape = circle];</span>
<span class="si">%s</span><span class="s1"></span>
<span class="s1">}</span>
<span class="s1">&#39;&#39;&#39;</span>
def link(fr, nm, label):
return &#39; %s -&gt; %s [ label = &quot;%s&quot; ];&#39; % (fr, nm, label)
<span class="k">def</span> <span class="nf">link</span><span class="p">(</span><span class="n">fr</span><span class="p">,</span> <span class="n">nm</span><span class="p">,</span> <span class="n">label</span><span class="p">):</span>
<span class="k">return</span> <span class="s1">&#39; </span><span class="si">%s</span><span class="s1"> -&gt; </span><span class="si">%s</span><span class="s1"> [ label = &quot;</span><span class="si">%s</span><span class="s1">&quot; ];&#39;</span> <span class="o">%</span> <span class="p">(</span><span class="n">fr</span><span class="p">,</span> <span class="n">nm</span><span class="p">,</span> <span class="n">label</span><span class="p">)</span>
def make_graph(table, accepting):
return _template % (
&#39; &#39;.join(accepting),
&#39;\n&#39;.join(
link(from_, to, char)
for (from_, char), (to) in sorted(table.iteritems())
)
)
<span class="k">def</span> <span class="nf">make_graph</span><span class="p">(</span><span class="n">table</span><span class="p">,</span> <span class="n">accepting</span><span class="p">):</span>
<span class="k">return</span> <span class="n">_template</span> <span class="o">%</span> <span class="p">(</span>
<span class="s1">&#39; &#39;</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">accepting</span><span class="p">),</span>
<span class="s1">&#39;</span><span class="se">\n</span><span class="s1">&#39;</span><span class="o">.</span><span class="n">join</span><span class="p">(</span>
<span class="n">link</span><span class="p">(</span><span class="n">from_</span><span class="p">,</span> <span class="n">to</span><span class="p">,</span> <span class="n">char</span><span class="p">)</span>
<span class="k">for</span> <span class="p">(</span><span class="n">from_</span><span class="p">,</span> <span class="n">char</span><span class="p">),</span> <span class="p">(</span><span class="n">to</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">table</span><span class="o">.</span><span class="n">iteritems</span><span class="p">())</span>
<span class="p">)</span>
<span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>print make_graph(table, accepting)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="nb">print</span> <span class="n">make_graph</span><span class="p">(</span><span class="n">table</span><span class="p">,</span> <span class="n">accepting</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">digraph</span> <span class="n">finite_state_machine</span> <span class="p">{</span>
@@ -699,14 +699,14 @@ hard-code the information in the table into a little patch of branches.</p>
<h4>Trampoline Function<a class="headerlink" href="#trampoline-function" title="Permalink to this headline"></a></h4>
<p>Python has no GOTO statement but we can fake it with a “trampoline”
function.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def trampoline(input_, jump_from, accepting):
I = iter(input_)
while True:
try:
bounce_to = jump_from(I)
except StopIteration:
return jump_from in accepting
jump_from = bounce_to
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">trampoline</span><span class="p">(</span><span class="n">input_</span><span class="p">,</span> <span class="n">jump_from</span><span class="p">,</span> <span class="n">accepting</span><span class="p">):</span>
<span class="n">I</span> <span class="o">=</span> <span class="nb">iter</span><span class="p">(</span><span class="n">input_</span><span class="p">)</span>
<span class="k">while</span> <span class="kc">True</span><span class="p">:</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">bounce_to</span> <span class="o">=</span> <span class="n">jump_from</span><span class="p">(</span><span class="n">I</span><span class="p">)</span>
<span class="k">except</span> <span class="ne">StopIteration</span><span class="p">:</span>
<span class="k">return</span> <span class="n">jump_from</span> <span class="ow">in</span> <span class="n">accepting</span>
<span class="n">jump_from</span> <span class="o">=</span> <span class="n">bounce_to</span>
</pre></div>
</div>
</section>
@@ -714,17 +714,17 @@ function.</p>
<h4>Stream Functions<a class="headerlink" href="#stream-functions" title="Permalink to this headline"></a></h4>
<p>Little helpers to process the iterator of our data (a “stream” of “1”
and “0” characters, not bits.)</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>getch = lambda I: int(next(I))
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">getch</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="nb">int</span><span class="p">(</span><span class="nb">next</span><span class="p">(</span><span class="n">I</span><span class="p">))</span>
def _1(I):
&#39;&#39;&#39;Loop on ones.&#39;&#39;&#39;
while getch(I): pass
<span class="k">def</span> <span class="nf">_1</span><span class="p">(</span><span class="n">I</span><span class="p">):</span>
<span class="sd">&#39;&#39;&#39;Loop on ones.&#39;&#39;&#39;</span>
<span class="k">while</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">):</span> <span class="k">pass</span>
def _0(I):
&#39;&#39;&#39;Loop on zeros.&#39;&#39;&#39;
while not getch(I): pass
<span class="k">def</span> <span class="nf">_0</span><span class="p">(</span><span class="n">I</span><span class="p">):</span>
<span class="sd">&#39;&#39;&#39;Loop on zeros.&#39;&#39;&#39;</span>
<span class="k">while</span> <span class="ow">not</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">):</span> <span class="k">pass</span>
</pre></div>
</div>
</section>
@@ -735,28 +735,28 @@ def _0(I):
code. (You have to imagine that these are GOTO statements in C or
branches in assembly and that the state names are branch destination
labels.)</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>a = lambda I: c if getch(I) else b
b = lambda I: _0(I) or d
c = lambda I: e if getch(I) else b
d = lambda I: f if getch(I) else b
e = lambda I: g if getch(I) else b
f = lambda I: h if getch(I) else b
g = lambda I: _1(I) or i
h = lambda I: _1(I) or i
i = lambda I: _0(I) or j
j = lambda I: h if getch(I) else i
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">a</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">c</span> <span class="k">if</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="k">else</span> <span class="n">b</span>
<span class="n">b</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">_0</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="ow">or</span> <span class="n">d</span>
<span class="n">c</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">e</span> <span class="k">if</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="k">else</span> <span class="n">b</span>
<span class="n">d</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">f</span> <span class="k">if</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="k">else</span> <span class="n">b</span>
<span class="n">e</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">g</span> <span class="k">if</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="k">else</span> <span class="n">b</span>
<span class="n">f</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">h</span> <span class="k">if</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="k">else</span> <span class="n">b</span>
<span class="n">g</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">_1</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="ow">or</span> <span class="n">i</span>
<span class="n">h</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">_1</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="ow">or</span> <span class="n">i</span>
<span class="n">i</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">_0</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="ow">or</span> <span class="n">j</span>
<span class="n">j</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">I</span><span class="p">:</span> <span class="n">h</span> <span class="k">if</span> <span class="n">getch</span><span class="p">(</span><span class="n">I</span><span class="p">)</span> <span class="k">else</span> <span class="n">i</span>
</pre></div>
</div>
<p>Note that the implementations of <code class="docutils literal notranslate"><span class="pre">h</span></code> and <code class="docutils literal notranslate"><span class="pre">g</span></code> are identical ergo
<code class="docutils literal notranslate"><span class="pre">h</span> <span class="pre">=</span> <span class="pre">g</span></code> and we could eliminate one in the code but <code class="docutils literal notranslate"><span class="pre">h</span></code> is an
accepting state and <code class="docutils literal notranslate"><span class="pre">g</span></code> isnt.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def acceptable(input_):
return trampoline(input_, a, {h, i})
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">acceptable</span><span class="p">(</span><span class="n">input_</span><span class="p">):</span>
<span class="k">return</span> <span class="n">trampoline</span><span class="p">(</span><span class="n">input_</span><span class="p">,</span> <span class="n">a</span><span class="p">,</span> <span class="p">{</span><span class="n">h</span><span class="p">,</span> <span class="n">i</span><span class="p">})</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>for n in range(2**5):
s = bin(n)[2:]
print &#39;%05s&#39; % s, acceptable(s)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">n</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">2</span><span class="o">**</span><span class="mi">5</span><span class="p">):</span>
<span class="n">s</span> <span class="o">=</span> <span class="nb">bin</span><span class="p">(</span><span class="n">n</span><span class="p">)[</span><span class="mi">2</span><span class="p">:]</span>
<span class="nb">print</span> <span class="s1">&#39;</span><span class="si">%05s</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="n">s</span><span class="p">,</span> <span class="n">acceptable</span><span class="p">(</span><span class="n">s</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="mi">0</span> <span class="kc">False</span>
File diff suppressed because one or more lines are too long
File diff suppressed because one or more lines are too long
@@ -157,33 +157,33 @@ like that.</p>
</section>
<section id="examples">
<h3>Examples<a class="headerlink" href="#examples" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>joy.parser.text_to_expression(&#39;1 2 3 4 5&#39;) # A simple sequence.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">joy</span><span class="o">.</span><span class="n">parser</span><span class="o">.</span><span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;1 2 3 4 5&#39;</span><span class="p">)</span> <span class="c1"># A simple sequence.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="p">(</span><span class="mi">4</span><span class="p">,</span> <span class="p">(</span><span class="mi">5</span><span class="p">,</span> <span class="p">())))))</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>joy.parser.text_to_expression(&#39;[1 2 3] 4 5&#39;) # Three items, the first is a list with three items
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">joy</span><span class="o">.</span><span class="n">parser</span><span class="o">.</span><span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;[1 2 3] 4 5&#39;</span><span class="p">)</span> <span class="c1"># Three items, the first is a list with three items</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">((</span><span class="mi">1</span><span class="p">,</span> <span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="p">()))),</span> <span class="p">(</span><span class="mi">4</span><span class="p">,</span> <span class="p">(</span><span class="mi">5</span><span class="p">,</span> <span class="p">())))</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>joy.parser.text_to_expression(&#39;1 23 [&quot;four&quot; [-5.0] cons] 8888&#39;) # A mixed bag. cons is
# a Symbol, no lookup at
# parse-time. Haiku docs.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">joy</span><span class="o">.</span><span class="n">parser</span><span class="o">.</span><span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;1 23 [&quot;four&quot; [-5.0] cons] 8888&#39;</span><span class="p">)</span> <span class="c1"># A mixed bag. cons is</span>
<span class="c1"># a Symbol, no lookup at</span>
<span class="c1"># parse-time. Haiku docs.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="p">(</span><span class="mi">23</span><span class="p">,</span> <span class="p">((</span><span class="s1">&#39;four&#39;</span><span class="p">,</span> <span class="p">((</span><span class="o">-</span><span class="mf">5.0</span><span class="p">,</span> <span class="p">()),</span> <span class="p">(</span><span class="n">cons</span><span class="p">,</span> <span class="p">()))),</span> <span class="p">(</span><span class="mi">8888</span><span class="p">,</span> <span class="p">()))))</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>joy.parser.text_to_expression(&#39;[][][][][]&#39;) # Five empty lists.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">joy</span><span class="o">.</span><span class="n">parser</span><span class="o">.</span><span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;[][][][][]&#39;</span><span class="p">)</span> <span class="c1"># Five empty lists.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">((),</span> <span class="p">((),</span> <span class="p">((),</span> <span class="p">((),</span> <span class="p">((),</span> <span class="p">())))))</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>joy.parser.text_to_expression(&#39;[[[[[]]]]]&#39;) # Five nested lists.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">joy</span><span class="o">.</span><span class="n">parser</span><span class="o">.</span><span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;[[[[[]]]]]&#39;</span><span class="p">)</span> <span class="c1"># Five nested lists.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">((((((),</span> <span class="p">()),</span> <span class="p">()),</span> <span class="p">()),</span> <span class="p">()),</span> <span class="p">())</span>
@@ -199,7 +199,7 @@ the Joy system. There are simple functions such as addition <code class="docutil
<code class="docutils literal notranslate"><span class="pre">+</span></code>, the library module supports aliases), and combinators which
provide control-flow and higher-order operations.</p>
<p>Many of the functions are defined in Python, like <code class="docutils literal notranslate"><span class="pre">dip</span></code>:</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>print inspect.getsource(joy.library.dip)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="nb">print</span> <span class="n">inspect</span><span class="o">.</span><span class="n">getsource</span><span class="p">(</span><span class="n">joy</span><span class="o">.</span><span class="n">library</span><span class="o">.</span><span class="n">dip</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">dip</span><span class="p">(</span><span class="n">stack</span><span class="p">,</span> <span class="n">expression</span><span class="p">,</span> <span class="n">dictionary</span><span class="p">):</span>
@@ -212,7 +212,7 @@ provide control-flow and higher-order operations.</p>
When the interpreter executes a definition function that function just
pushes its body expression onto the pending expression (the
continuation) and returns control to the interpreter.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>print joy.library.definitions
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="nb">print</span> <span class="n">joy</span><span class="o">.</span><span class="n">library</span><span class="o">.</span><span class="n">definitions</span>
</pre></div>
</div>
<pre class="literal-block">second == rest first
@@ -63,7 +63,7 @@ the Sufficiently Smart Compiler can be modified to use an optimized
implementation under the hood. (Where does the “type” come from? It has
a contingent existence predicated on the disciplined use of these
functions on otherwise undistinguished Joy datastructures.)</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from notebook_preamble import D, J, V, define, DefinitionWrapper
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">notebook_preamble</span> <span class="kn">import</span> <span class="n">D</span><span class="p">,</span> <span class="n">J</span><span class="p">,</span> <span class="n">V</span><span class="p">,</span> <span class="n">define</span><span class="p">,</span> <span class="n">DefinitionWrapper</span>
</pre></div>
</div>
<section id="adding-nodes-to-the-tree">
@@ -100,10 +100,10 @@ functions on otherwise undistinguished Joy datastructures.)</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Tree</span><span class="o">-</span><span class="n">new</span> <span class="o">==</span> <span class="n">swap</span> <span class="p">[[]</span> <span class="p">[]]</span> <span class="n">cons</span> <span class="n">cons</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Tree-new == swap [[] []] cons cons&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Tree-new == swap [[] []] cons cons&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;&quot;v&quot; &quot;k&quot; Tree-new&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;&quot;v&quot; &quot;k&quot; Tree-new&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;k&#39;</span> <span class="s1">&#39;v&#39;</span> <span class="p">[]</span> <span class="p">[]]</span>
@@ -159,10 +159,10 @@ comparison operator:</p>
<span class="n">P</span> <span class="o">==</span> <span class="n">pop</span> <span class="n">roll</span><span class="o">&gt;</span> <span class="n">pop</span> <span class="n">first</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;P == pop roll&gt; pop first&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;P == pop roll&gt; pop first&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;old_key&quot; 23 [] []] 17 &quot;new_key&quot; [&quot;...&quot;] P&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;old_key&quot; 23 [] []] 17 &quot;new_key&quot; [&quot;...&quot;] P&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;new_key&#39;</span> <span class="s1">&#39;old_key&#39;</span>
@@ -217,10 +217,10 @@ stack:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">T</span> <span class="o">==</span> <span class="n">cons</span> <span class="n">cons</span> <span class="p">[</span><span class="n">dipdd</span><span class="p">]</span> <span class="n">cons</span> <span class="n">infra</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;T == cons cons [dipdd] cons infra&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;T == cons cons [dipdd] cons infra&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;old_k&quot; &quot;old_value&quot; &quot;left&quot; &quot;right&quot;] &quot;new_value&quot; &quot;new_key&quot; [&quot;Tree-add&quot;] T&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;old_k&quot; &quot;old_value&quot; &quot;left&quot; &quot;right&quot;] &quot;new_value&quot; &quot;new_key&quot; [&quot;Tree-add&quot;] T&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;old_k&#39;</span> <span class="s1">&#39;old_value&#39;</span> <span class="s1">&#39;left&#39;</span> <span class="s1">&#39;Tree-add&#39;</span> <span class="s1">&#39;new_key&#39;</span> <span class="s1">&#39;new_value&#39;</span> <span class="s1">&#39;right&#39;</span><span class="p">]</span>
@@ -234,7 +234,7 @@ stack:</p>
<span class="p">[</span><span class="n">key_n</span> <span class="n">value_n</span> <span class="n">left</span> <span class="n">right</span><span class="p">]</span> <span class="n">value</span> <span class="n">key</span> <span class="p">[</span><span class="n">Tree</span><span class="o">-</span><span class="n">add</span><span class="p">]</span> <span class="p">[</span><span class="n">P</span> <span class="o">&lt;</span><span class="p">]</span> <span class="p">[</span><span class="n">Te</span><span class="p">]</span> <span class="p">[</span><span class="n">Ee</span><span class="p">]</span> <span class="n">ifte</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;E == [P &lt;] [Te] [Ee] ifte&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;E == [P &lt;] [Te] [Ee] ifte&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>In this case <code class="docutils literal notranslate"><span class="pre">Te</span></code> works that same as <code class="docutils literal notranslate"><span class="pre">T</span></code> but on the left child tree
@@ -243,10 +243,10 @@ instead of the right, so the only difference is that it must use
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Te</span> <span class="o">==</span> <span class="n">cons</span> <span class="n">cons</span> <span class="p">[</span><span class="n">dipd</span><span class="p">]</span> <span class="n">cons</span> <span class="n">infra</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Te == cons cons [dipd] cons infra&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Te == cons cons [dipd] cons infra&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;old_k&quot; &quot;old_value&quot; &quot;left&quot; &quot;right&quot;] &quot;new_value&quot; &quot;new_key&quot; [&quot;Tree-add&quot;] Te&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;old_k&quot; &quot;old_value&quot; &quot;left&quot; &quot;right&quot;] &quot;new_value&quot; &quot;new_key&quot; [&quot;Tree-add&quot;] Te&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;old_k&#39;</span> <span class="s1">&#39;old_value&#39;</span> <span class="s1">&#39;Tree-add&#39;</span> <span class="s1">&#39;new_key&#39;</span> <span class="s1">&#39;new_value&#39;</span> <span class="s1">&#39;left&#39;</span> <span class="s1">&#39;right&#39;</span><span class="p">]</span>
@@ -274,10 +274,10 @@ instead of the right, so the only difference is that it must use
<span class="p">[</span><span class="n">key</span> <span class="n">new_value</span> <span class="n">left</span> <span class="n">right</span><span class="p">]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Ee == pop swap roll&lt; rest rest cons cons&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Ee == pop swap roll&lt; rest rest cons cons&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;k&quot; &quot;old_value&quot; &quot;left&quot; &quot;right&quot;] &quot;new_value&quot; &quot;k&quot; [&quot;Tree-add&quot;] Ee&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;k&quot; &quot;old_value&quot; &quot;left&quot; &quot;right&quot;] &quot;new_value&quot; &quot;k&quot; [&quot;Tree-add&quot;] Ee&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;k&#39;</span> <span class="s1">&#39;new_value&#39;</span> <span class="s1">&#39;left&#39;</span> <span class="s1">&#39;right&#39;</span><span class="p">]</span>
@@ -302,43 +302,43 @@ instead of the right, so the only difference is that it must use
<span class="n">Tree</span><span class="o">-</span><span class="n">add</span> <span class="o">==</span> <span class="p">[</span><span class="n">popop</span> <span class="ow">not</span><span class="p">]</span> <span class="p">[[</span><span class="n">pop</span><span class="p">]</span> <span class="n">dipd</span> <span class="n">Tree</span><span class="o">-</span><span class="n">new</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[</span><span class="n">R</span><span class="p">]</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Tree-add == [popop not] [[pop] dipd Tree-new] [] [[P &gt;] [T] [E] ifte] genrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Tree-add == [popop not] [[pop] dipd Tree-new] [] [[P &gt;] [T] [E] ifte] genrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="examples">
<h3>Examples<a class="headerlink" href="#examples" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] 23 &quot;b&quot; Tree-add&#39;) # Initial
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] 23 &quot;b&quot; Tree-add&#39;</span><span class="p">)</span> <span class="c1"># Initial</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">23</span> <span class="p">[]</span> <span class="p">[]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;b&quot; 23 [] []] 88 &quot;c&quot; Tree-add&#39;) # Greater than
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;b&quot; 23 [] []] 88 &quot;c&quot; Tree-add&#39;</span><span class="p">)</span> <span class="c1"># Greater than</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">23</span> <span class="p">[]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;b&quot; 23 [] []] 88 &quot;a&quot; Tree-add&#39;) # Less than
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;b&quot; 23 [] []] 88 &quot;a&quot; Tree-add&#39;</span><span class="p">)</span> <span class="c1"># Less than</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">23</span> <span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;b&quot; 23 [] []] 88 &quot;b&quot; Tree-add&#39;) # Equal to
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;b&quot; 23 [] []] 88 &quot;b&quot; Tree-add&#39;</span><span class="p">)</span> <span class="c1"># Equal to</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] 23 &quot;b&quot; Tree-add 88 &quot;a&quot; Tree-add 44 &quot;c&quot; Tree-add&#39;) # Series.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] 23 &quot;b&quot; Tree-add 88 &quot;a&quot; Tree-add 44 &quot;c&quot; Tree-add&#39;</span><span class="p">)</span> <span class="c1"># Series.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">23</span> <span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">44</span> <span class="p">[]</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] [[23 &quot;b&quot;] [88 &quot;a&quot;] [44 &quot;c&quot;]] [i Tree-add] step&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] [[23 &quot;b&quot;] [88 &quot;a&quot;] [44 &quot;c&quot;]] [i Tree-add] step&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">23</span> <span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">44</span> <span class="p">[]</span> <span class="p">[]]]</span>
@@ -365,19 +365,19 @@ values:</p>
<span class="n">L</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;1 0 [&#39;G&#39;] [&#39;E&#39;] [&#39;L&#39;] cmp&quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;1 0 [&#39;G&#39;] [&#39;E&#39;] [&#39;L&#39;] cmp&quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;G&#39;</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;1 1 [&#39;G&#39;] [&#39;E&#39;] [&#39;L&#39;] cmp&quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;1 1 [&#39;G&#39;] [&#39;E&#39;] [&#39;L&#39;] cmp&quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;E&#39;</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;0 1 [&#39;G&#39;] [&#39;E&#39;] [&#39;L&#39;] cmp&quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;0 1 [&#39;G&#39;] [&#39;E&#39;] [&#39;L&#39;] cmp&quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;L&#39;</span>
@@ -414,7 +414,7 @@ node key (by throwing everything else away):</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">P</span> <span class="o">==</span> <span class="n">over</span> <span class="p">[</span><span class="n">popop</span> <span class="n">popop</span> <span class="n">first</span><span class="p">]</span> <span class="n">nullary</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;P == over [popop popop first] nullary&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;P == over [popop popop first] nullary&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Using <code class="docutils literal notranslate"><span class="pre">cmp</span></code> to simplify <cite>our code above at
@@ -434,10 +434,10 @@ to understand:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Tree</span><span class="o">-</span><span class="n">add</span> <span class="o">==</span> <span class="p">[</span><span class="n">popop</span> <span class="ow">not</span><span class="p">]</span> <span class="p">[[</span><span class="n">pop</span><span class="p">]</span> <span class="n">dipd</span> <span class="n">Tree</span><span class="o">-</span><span class="n">new</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[</span><span class="n">P</span> <span class="p">[</span><span class="n">T</span><span class="p">]</span> <span class="p">[</span><span class="n">Ee</span><span class="p">]</span> <span class="p">[</span><span class="n">Te</span><span class="p">]</span> <span class="n">cmp</span><span class="p">]</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Tree-add == [popop not] [[pop] dipd Tree-new] [] [P [T] [Ee] [Te] cmp] genrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Tree-add == [popop not] [[pop] dipd Tree-new] [] [P [T] [Ee] [Te] cmp] genrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] 23 &quot;b&quot; Tree-add 88 &quot;a&quot; Tree-add 44 &quot;c&quot; Tree-add&#39;) # Still works.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] 23 &quot;b&quot; Tree-add 88 &quot;a&quot; Tree-add 44 &quot;c&quot; Tree-add&#39;</span><span class="p">)</span> <span class="c1"># Still works.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">23</span> <span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">44</span> <span class="p">[]</span> <span class="p">[]]]</span>
@@ -545,22 +545,22 @@ with an interesting situation:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Tree</span><span class="o">-</span><span class="nb">iter</span> <span class="o">==</span> <span class="p">[</span><span class="ow">not</span><span class="p">]</span> <span class="p">[</span><span class="n">pop</span><span class="p">]</span> <span class="n">roll</span><span class="o">&lt;</span> <span class="p">[</span><span class="n">dupdip</span> <span class="n">rest</span> <span class="n">rest</span><span class="p">]</span> <span class="n">cons</span> <span class="p">[</span><span class="n">step</span><span class="p">]</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Tree-iter == [not] [pop] roll&lt; [dupdip rest rest] cons [step] genrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Tree-iter == [not] [pop] roll&lt; [dupdip rest rest] cons [step] genrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="id1">
<h3>Examples<a class="headerlink" href="#id1" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] [foo] Tree-iter&#39;) # It doesn&#39;t matter what F is as it won&#39;t be used.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] [foo] Tree-iter&#39;</span><span class="p">)</span> <span class="c1"># It doesn&#39;t matter what F is as it won&#39;t be used.</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[&#39;b&#39; 23 [&#39;a&#39; 88 [] []] [&#39;c&#39; 44 [] []]] [first] Tree-iter&quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[&#39;b&#39; 23 [&#39;a&#39; 88 [] []] [&#39;c&#39; 44 [] []]] [first] Tree-iter&quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;b&#39;</span> <span class="s1">&#39;a&#39;</span> <span class="s1">&#39;c&#39;</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[&#39;b&#39; 23 [&#39;a&#39; 88 [] []] [&#39;c&#39; 44 [] []]] [second] Tree-iter&quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[&#39;b&#39; 23 [&#39;a&#39; 88 [] []] [&#39;c&#39; 44 [] []]] [second] Tree-iter&quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">23</span> <span class="mi">88</span> <span class="mi">44</span>
@@ -575,16 +575,16 @@ to e.g. 0 and ignoring them. Its set-like in that duplicate items added
to it will only occur once within it, and we can query it in
<cite>:math:`O(log_2 N)</cite> &lt;<a class="reference external" href="https://en.wikipedia.org/wiki/Binary_search_tree#cite_note-2">https://en.wikipedia.org/wiki/Binary_search_tree#cite_note-2</a>&gt;`__
time.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] [3 9 5 2 8 6 7 8 4] [0 swap Tree-add] step&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] [3 9 5 2 8 6 7 8 4] [0 swap Tree-add] step&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">3</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">9</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">5</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">8</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">6</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[</span><span class="mi">7</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]]</span> <span class="p">[]]]</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;to_set == [] swap [0 swap Tree-add] step&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;to_set == [] swap [0 swap Tree-add] step&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[3 9 5 2 8 6 7 8 4] to_set&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[3 9 5 2 8 6 7 8 4] to_set&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">3</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">9</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">5</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">8</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">6</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[</span><span class="mi">7</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]]</span> <span class="p">[]]]</span> <span class="p">[]]]</span>
@@ -592,10 +592,10 @@ time.</p>
</div>
<p>And with that we can write a little program <code class="docutils literal notranslate"><span class="pre">unique</span></code> to remove
duplicate items from a list.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;unique == [to_set [first] Tree-iter] cons run&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;unique == [to_set [first] Tree-iter] cons run&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[3 9 3 5 2 9 8 8 8 6 2 7 8 4 3] unique&#39;) # Filter duplicate items.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[3 9 3 5 2 9 8 8 8 6 2 7 8 4 3] unique&#39;</span><span class="p">)</span> <span class="c1"># Filter duplicate items.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">7</span> <span class="mi">6</span> <span class="mi">8</span> <span class="mi">4</span> <span class="mi">5</span> <span class="mi">9</span> <span class="mi">2</span> <span class="mi">3</span><span class="p">]</span>
@@ -679,23 +679,23 @@ right side:</p>
</pre></div>
</div>
<p>Now we can sort sequences.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>#define(&#39;Tree-iter-order == [not] [pop] [dup third] [[cons dip] dupdip [[first] dupdip] dip [rest rest rest first] dip i] genrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="c1">#define(&#39;Tree-iter-order == [not] [pop] [dup third] [[cons dip] dupdip [[first] dupdip] dip [rest rest rest first] dip i] genrec&#39;)</span>
DefinitionWrapper.add_definitions(&#39;&#39;&#39;
<span class="n">DefinitionWrapper</span><span class="o">.</span><span class="n">add_definitions</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
fourth == rest rest rest first
<span class="s1">fourth == rest rest rest first</span>
proc_left == [cons dip] dupdip
proc_current == [[first] dupdip] dip
proc_right == [fourth] dip i
<span class="s1">proc_left == [cons dip] dupdip</span>
<span class="s1">proc_current == [[first] dupdip] dip</span>
<span class="s1">proc_right == [fourth] dip i</span>
Tree-iter-order == [not] [pop] [dup third] [proc_left proc_current proc_right] genrec
<span class="s1">Tree-iter-order == [not] [pop] [dup third] [proc_left proc_current proc_right] genrec</span>
&#39;&#39;&#39;, D)
<span class="s1">&#39;&#39;&#39;</span><span class="p">,</span> <span class="n">D</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[3 9 5 2 8 6 7 8 4] to_set Tree-iter-order&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[3 9 5 2 8 6 7 8 4] to_set Tree-iter-order&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">2</span> <span class="mi">3</span> <span class="mi">4</span> <span class="mi">5</span> <span class="mi">6</span> <span class="mi">7</span> <span class="mi">8</span> <span class="mi">9</span>
@@ -835,54 +835,54 @@ because theres no value to discard.</p>
<span class="n">Tree</span><span class="o">-</span><span class="n">get</span> <span class="o">==</span> <span class="p">[</span><span class="n">pop</span> <span class="ow">not</span><span class="p">]</span> <span class="n">swap</span> <span class="p">[]</span> <span class="p">[</span><span class="n">P</span> <span class="p">[</span><span class="n">T</span><span class="o">&gt;</span><span class="p">]</span> <span class="p">[</span><span class="n">E</span><span class="p">]</span> <span class="p">[</span><span class="n">T</span><span class="o">&lt;</span><span class="p">]</span> <span class="n">cmp</span><span class="p">]</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span># I don&#39;t want to deal with name conflicts with the above so I&#39;m inlining everything here.
# The original Joy system has &quot;hide&quot; which is a meta-command which allows you to use named
# definitions that are only in scope for a given definition. I don&#39;t want to implement
# that (yet) so...
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="c1"># I don&#39;t want to deal with name conflicts with the above so I&#39;m inlining everything here.</span>
<span class="c1"># The original Joy system has &quot;hide&quot; which is a meta-command which allows you to use named</span>
<span class="c1"># definitions that are only in scope for a given definition. I don&#39;t want to implement</span>
<span class="c1"># that (yet) so...</span>
define(&#39;&#39;&#39;
Tree-get == [pop not] swap [] [
over [pop popop first] nullary
[[fourth] dipd i]
[popop second]
[[third] dipd i]
cmp
] genrec
&#39;&#39;&#39;)
<span class="n">define</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
<span class="s1">Tree-get == [pop not] swap [] [</span>
<span class="s1"> over [pop popop first] nullary</span>
<span class="s1"> [[fourth] dipd i]</span>
<span class="s1"> [popop second]</span>
<span class="s1"> [[third] dipd i]</span>
<span class="s1"> cmp</span>
<span class="s1"> ] genrec</span>
<span class="s1">&#39;&#39;&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;gary&quot; 23 [] []] &quot;mike&quot; [popd &quot; not in tree&quot; +] Tree-get&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;gary&quot; 23 [] []] &quot;mike&quot; [popd &quot; not in tree&quot; +] Tree-get&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;mike not in tree&#39;</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[&quot;gary&quot; 23 [] []] &quot;gary&quot; [popop &quot;err&quot;] Tree-get&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[&quot;gary&quot; 23 [] []] &quot;gary&quot; [popop &quot;err&quot;] Tree-get&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">23</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
[] [[0 &#39;a&#39;] [1 &#39;b&#39;] [2 &#39;c&#39;]] [i Tree-add] step
<span class="s1"> [] [[0 &#39;a&#39;] [1 &#39;b&#39;] [2 &#39;c&#39;]] [i Tree-add] step</span>
&#39;c&#39; [popop &#39;not found&#39;] Tree-get
<span class="s1"> &#39;c&#39; [popop &#39;not found&#39;] Tree-get</span>
&#39;&#39;&#39;)
<span class="s1">&#39;&#39;&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">2</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
[] [[0 &#39;a&#39;] [1 &#39;b&#39;] [2 &#39;c&#39;]] [i Tree-add] step
<span class="s1"> [] [[0 &#39;a&#39;] [1 &#39;b&#39;] [2 &#39;c&#39;]] [i Tree-add] step</span>
&#39;d&#39; [popop &#39;not found&#39;] Tree-get
<span class="s1"> &#39;d&#39; [popop &#39;not found&#39;] Tree-get</span>
&#39;&#39;&#39;)
<span class="s1">&#39;&#39;&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;not found&#39;</span>
@@ -1175,61 +1175,61 @@ E == [
</div>
<p>By the standards of the code Ive written so far, this is a <em>huge</em> Joy
program.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>DefinitionWrapper.add_definitions(&#39;&#39;&#39;
first_two == uncons uncons pop
fourth == rest rest rest first
?fourth == [] [fourth] [] ifte
W.rightmost == [?fourth] [fourth] while
E.clear_stuff == roll&gt; popop rest
E.delete == cons dipd
W == dup W.rightmost first_two over
E.0 == E.clear_stuff [W] dip E.delete swap
E == [[[pop third not] pop fourth] [[pop fourth not] pop third] [[E.0] cons infra]] cond
T&gt; == [dipd] cons infra
T&lt; == [dipdd] cons infra
R0 == over first swap dup
R1 == cons roll&gt; [T&gt;] [E] [T&lt;] cmp
Tree-Delete == [pop not] [pop] [R0] [R1] genrec
&#39;&#39;&#39;, D)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">DefinitionWrapper</span><span class="o">.</span><span class="n">add_definitions</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
<span class="s1">first_two == uncons uncons pop</span>
<span class="s1">fourth == rest rest rest first</span>
<span class="s1">?fourth == [] [fourth] [] ifte</span>
<span class="s1">W.rightmost == [?fourth] [fourth] while</span>
<span class="s1">E.clear_stuff == roll&gt; popop rest</span>
<span class="s1">E.delete == cons dipd</span>
<span class="s1">W == dup W.rightmost first_two over</span>
<span class="s1">E.0 == E.clear_stuff [W] dip E.delete swap</span>
<span class="s1">E == [[[pop third not] pop fourth] [[pop fourth not] pop third] [[E.0] cons infra]] cond</span>
<span class="s1">T&gt; == [dipd] cons infra</span>
<span class="s1">T&lt; == [dipdd] cons infra</span>
<span class="s1">R0 == over first swap dup</span>
<span class="s1">R1 == cons roll&gt; [T&gt;] [E] [T&lt;] cmp</span>
<span class="s1">Tree-Delete == [pop not] [pop] [R0] [R1] genrec</span>
<span class="s1">&#39;&#39;&#39;</span><span class="p">,</span> <span class="n">D</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;c&#39; Tree-Delete &quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;c&#39; Tree-Delete &quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">23</span> <span class="p">[]</span> <span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;b&#39; Tree-Delete &quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;b&#39; Tree-Delete &quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">23</span> <span class="p">[]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">44</span> <span class="p">[]</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;a&#39; Tree-Delete &quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;a&#39; Tree-Delete &quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">44</span> <span class="p">[]</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;der&#39; Tree-Delete &quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[&#39;a&#39; 23 [] [&#39;b&#39; 88 [] [&#39;c&#39; 44 [] []]]] &#39;der&#39; Tree-Delete &quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;a&#39;</span> <span class="mi">23</span> <span class="p">[]</span> <span class="p">[</span><span class="s1">&#39;b&#39;</span> <span class="mi">88</span> <span class="p">[]</span> <span class="p">[</span><span class="s1">&#39;c&#39;</span> <span class="mi">44</span> <span class="p">[]</span> <span class="p">[]]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] [4 2 3 1 6 7 5 ] [0 swap Tree-add] step&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] [4 2 3 1 6 7 5 ] [0 swap Tree-add] step&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">4</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">1</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]]</span> <span class="p">[</span><span class="mi">6</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">5</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">7</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[4 0 [2 0 [1 0 [] []] [3 0 [] []]] [6 0 [5 0 [] []] [7 0 [] []]]] 3 Tree-Delete &quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[4 0 [2 0 [1 0 [] []] [3 0 [] []]] [6 0 [5 0 [] []] [7 0 [] []]]] 3 Tree-Delete &quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">4</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">1</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">6</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">5</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">7</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&quot;[4 0 [2 0 [1 0 [] []] [3 0 [] []]] [6 0 [5 0 [] []] [7 0 [] []]]] 4 Tree-Delete &quot;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s2">&quot;[4 0 [2 0 [1 0 [] []] [3 0 [] []]] [6 0 [5 0 [] []] [7 0 [] []]]] 4 Tree-Delete &quot;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">3</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">1</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">6</span> <span class="mi">0</span> <span class="p">[</span><span class="mi">5</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[</span><span class="mi">7</span> <span class="mi">0</span> <span class="p">[]</span> <span class="p">[]]]]</span>
@@ -34,7 +34,7 @@
<div class="body" role="main">
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from notebook_preamble import J, V, define
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">notebook_preamble</span> <span class="kn">import</span> <span class="n">J</span><span class="p">,</span> <span class="n">V</span><span class="p">,</span> <span class="n">define</span>
</pre></div>
</div>
<section id="quadratic-formula">
@@ -100,11 +100,11 @@ the variables:</p>
</div>
<p>The three arguments are to the left, so we can “chop off” everything to
the right and say its the definition of the <code class="docutils literal notranslate"><span class="pre">quadratic</span></code> function:</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;quadratic == over [[[neg] dupdip sqr 4] dipd * * - sqrt pm] dip 2 * [/] cons app2&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;quadratic == over [[[neg] dupdip sqr 4] dipd * * - sqrt pm] dip 2 * [/] cons app2&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Lets try it out:</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;3 1 1 quadratic&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;3 1 1 quadratic&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="o">-</span><span class="mf">0.3819660112501051</span> <span class="o">-</span><span class="mf">2.618033988749895</span>
@@ -114,7 +114,7 @@ the right and say its the definition of the <code class="docutils literal not
lines are the <code class="docutils literal notranslate"><span class="pre">dip</span></code> and <code class="docutils literal notranslate"><span class="pre">dipd</span></code> combinators building the main program
by incorporating the values on the stack. Then that program runs and you
get the results. This is pretty typical of Joy code.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;-5 1 4 quadratic&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;-5 1 4 quadratic&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="o">-</span><span class="mi">5</span> <span class="mi">1</span> <span class="mi">4</span> <span class="n">quadratic</span>
@@ -33,7 +33,7 @@
<div class="body" role="main">
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from notebook_preamble import D, DefinitionWrapper, J, V, define
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">notebook_preamble</span> <span class="kn">import</span> <span class="n">D</span><span class="p">,</span> <span class="n">DefinitionWrapper</span><span class="p">,</span> <span class="n">J</span><span class="p">,</span> <span class="n">V</span><span class="p">,</span> <span class="n">define</span>
</pre></div>
</div>
<section id="recursion-combinators">
@@ -101,18 +101,18 @@ cons list”.</p></li>
</ul>
<p>It may be helpful to see this function implemented in imperative Python
code.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>def hylomorphism(c, F, P, G):
&#39;&#39;&#39;Return a hylomorphism function H.&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">hylomorphism</span><span class="p">(</span><span class="n">c</span><span class="p">,</span> <span class="n">F</span><span class="p">,</span> <span class="n">P</span><span class="p">,</span> <span class="n">G</span><span class="p">):</span>
<span class="sd">&#39;&#39;&#39;Return a hylomorphism function H.&#39;&#39;&#39;</span>
def H(a):
if P(a):
result = c
else:
b, aa = G(a)
result = F(b, H(aa)) # b is stored in the stack frame during recursive call to H().
return result
<span class="k">def</span> <span class="nf">H</span><span class="p">(</span><span class="n">a</span><span class="p">):</span>
<span class="k">if</span> <span class="n">P</span><span class="p">(</span><span class="n">a</span><span class="p">):</span>
<span class="n">result</span> <span class="o">=</span> <span class="n">c</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">b</span><span class="p">,</span> <span class="n">aa</span> <span class="o">=</span> <span class="n">G</span><span class="p">(</span><span class="n">a</span><span class="p">)</span>
<span class="n">result</span> <span class="o">=</span> <span class="n">F</span><span class="p">(</span><span class="n">b</span><span class="p">,</span> <span class="n">H</span><span class="p">(</span><span class="n">aa</span><span class="p">))</span> <span class="c1"># b is stored in the stack frame during recursive call to H().</span>
<span class="k">return</span> <span class="n">result</span>
return H
<span class="k">return</span> <span class="n">H</span>
</pre></div>
</div>
<p>Cf. <a class="reference external" href="http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.41.125">“Bananas, Lenses, &amp; Barbed
@@ -185,7 +185,7 @@ the left so we have a definition for <code class="docutils literal notranslate">
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">hylomorphism</span> <span class="o">==</span> <span class="p">[</span><span class="n">unit</span> <span class="p">[</span><span class="n">pop</span><span class="p">]</span> <span class="n">swoncat</span><span class="p">]</span> <span class="n">dipd</span> <span class="p">[</span><span class="n">dip</span><span class="p">]</span> <span class="n">swoncat</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;hylomorphism == [unit [pop] swoncat] dipd [dip] swoncat genrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;hylomorphism == [unit [pop] swoncat] dipd [dip] swoncat genrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<section id="example-finding-triangular-numbers">
@@ -200,17 +200,17 @@ of all positive integers less than that one. (In this case the types
<li><p><code class="docutils literal notranslate"><span class="pre">[G]</span></code> is <code class="docutils literal notranslate"><span class="pre">[--</span> <span class="pre">dup]</span></code></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">[F]</span></code> is <code class="docutils literal notranslate"><span class="pre">[+]</span></code></p></li>
</ul>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;triangular_number == [1 &lt;=] 0 [-- dup] [+] hylomorphism&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;triangular_number == [1 &lt;=] 0 [-- dup] [+] hylomorphism&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Lets try it:</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;5 triangular_number&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;5 triangular_number&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">10</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[0 1 2 3 4 5 6] [triangular_number] map&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[0 1 2 3 4 5 6] [triangular_number] map&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">0</span> <span class="mi">0</span> <span class="mi">1</span> <span class="mi">3</span> <span class="mi">6</span> <span class="mi">10</span> <span class="mi">15</span><span class="p">]</span>
@@ -372,10 +372,10 @@ values.</p>
<span class="o">==</span> <span class="p">[</span><span class="mi">0</span> <span class="o">&lt;=</span><span class="p">]</span> <span class="p">[</span><span class="n">pop</span> <span class="p">[]]</span> <span class="p">[</span><span class="o">--</span> <span class="n">dup</span><span class="p">]</span> <span class="p">[</span><span class="n">dip</span> <span class="n">swons</span><span class="p">]</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;range == [0 &lt;=] [] [-- dup] [swons] hylomorphism&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;range == [0 &lt;=] [] [-- dup] [swons] hylomorphism&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;5 range&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;5 range&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">4</span> <span class="mi">3</span> <span class="mi">2</span> <span class="mi">1</span> <span class="mi">0</span><span class="p">]</span>
@@ -388,10 +388,10 @@ values.</p>
<span class="o">==</span> <span class="p">[]</span> <span class="n">swap</span> <span class="p">[</span><span class="mi">0</span> <span class="o">&lt;=</span><span class="p">]</span> <span class="p">[</span><span class="n">pop</span><span class="p">]</span> <span class="p">[</span><span class="o">--</span> <span class="n">dup</span> <span class="p">[</span><span class="n">swons</span><span class="p">]</span> <span class="n">dip</span><span class="p">]</span> <span class="n">primrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;range_reverse == [] swap [0 &lt;=] [pop] [-- dup [swons] dip] primrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;range_reverse == [] swap [0 &lt;=] [pop] [-- dup [swons] dip] primrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;5 range_reverse&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;5 range_reverse&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">0</span> <span class="mi">1</span> <span class="mi">2</span> <span class="mi">3</span> <span class="mi">4</span><span class="p">]</span>
@@ -404,10 +404,10 @@ values.</p>
<span class="o">==</span> <span class="p">[</span><span class="mi">0</span> <span class="o">&lt;=</span><span class="p">]</span> <span class="p">[</span><span class="n">pop</span> <span class="p">[]]</span> <span class="p">[[</span><span class="o">--</span><span class="p">]</span> <span class="n">dupdip</span><span class="p">]</span> <span class="p">[</span><span class="n">dip</span> <span class="n">swons</span><span class="p">]</span> <span class="n">genrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;ranger == [0 &lt;=] [pop []] [[--] dupdip] [dip swons] genrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;ranger == [0 &lt;=] [pop []] [[--] dupdip] [dip swons] genrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;5 ranger&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;5 ranger&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">5</span> <span class="mi">4</span> <span class="mi">3</span> <span class="mi">2</span> <span class="mi">1</span><span class="p">]</span>
@@ -420,10 +420,10 @@ values.</p>
<span class="o">==</span> <span class="p">[]</span> <span class="n">swap</span> <span class="p">[</span><span class="mi">0</span> <span class="o">&lt;=</span><span class="p">]</span> <span class="p">[</span><span class="n">pop</span><span class="p">]</span> <span class="p">[[</span><span class="n">swons</span><span class="p">]</span> <span class="n">dupdip</span> <span class="o">--</span><span class="p">]</span> <span class="n">primrec</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;ranger_reverse == [] swap [0 &lt;=] [pop] [[swons] dupdip --] primrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;ranger_reverse == [] swap [0 &lt;=] [pop] [[swons] dupdip --] primrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;5 ranger_reverse&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;5 ranger_reverse&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span> <span class="mi">2</span> <span class="mi">3</span> <span class="mi">4</span> <span class="mi">5</span><span class="p">]</span>
@@ -444,17 +444,17 @@ and makes some new value.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">C</span> <span class="o">==</span> <span class="p">[</span><span class="ow">not</span><span class="p">]</span> <span class="n">c</span> <span class="p">[</span><span class="n">uncons</span> <span class="n">swap</span><span class="p">]</span> <span class="p">[</span><span class="n">F</span><span class="p">]</span> <span class="n">hylomorphism</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;swuncons == uncons swap&#39;) # Awkward name.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;swuncons == uncons swap&#39;</span><span class="p">)</span> <span class="c1"># Awkward name.</span>
</pre></div>
</div>
<p>An example of a catamorphism is the sum function.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="nb">sum</span> <span class="o">==</span> <span class="p">[</span><span class="ow">not</span><span class="p">]</span> <span class="mi">0</span> <span class="p">[</span><span class="n">swuncons</span><span class="p">]</span> <span class="p">[</span><span class="o">+</span><span class="p">]</span> <span class="n">hylomorphism</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;sum == [not] 0 [swuncons] [+] hylomorphism&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;sum == [not] 0 [swuncons] [+] hylomorphism&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[5 4 3 2 1] sum&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[5 4 3 2 1] sum&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">15</span>
@@ -464,7 +464,7 @@ and makes some new value.</p>
<h3>The <code class="docutils literal notranslate"><span class="pre">step</span></code> combinator<a class="headerlink" href="#the-step-combinator" title="Permalink to this headline"></a></h3>
<p>The <code class="docutils literal notranslate"><span class="pre">step</span></code> combinator will usually be better to use than
<code class="docutils literal notranslate"><span class="pre">catamorphism</span></code>.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[step] help&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[step] help&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Run</span> <span class="n">a</span> <span class="n">quoted</span> <span class="n">program</span> <span class="n">on</span> <span class="n">each</span> <span class="n">item</span> <span class="ow">in</span> <span class="n">a</span> <span class="n">sequence</span><span class="o">.</span>
@@ -488,10 +488,10 @@ and makes some new value.</p>
<span class="n">on</span> <span class="n">top</span> <span class="n">of</span> <span class="n">the</span> <span class="n">stack</span><span class="o">.</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;sum == 0 swap [+] step&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;sum == 0 swap [+] step&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[5 4 3 2 1] sum&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[5 4 3 2 1] sum&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">15</span>
@@ -512,10 +512,10 @@ and makes some new value.</p>
<span class="n">P</span> <span class="o">==</span> <span class="mi">1</span> <span class="o">&lt;=</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;factorial == 1 swap [1 &lt;=] [pop] [[*] dupdip --] primrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;factorial == 1 swap [1 &lt;=] [pop] [[*] dupdip --] primrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;5 factorial&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;5 factorial&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">120</span>
@@ -544,10 +544,10 @@ pattern <code class="docutils literal notranslate"><span class="pre">H2</span></
<span class="n">P</span> <span class="o">==</span> <span class="ow">not</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;tails == [] swap [not] [pop] [rest dup [swons] dip] primrec&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;tails == [] swap [not] [pop] [rest dup [swons] dip] primrec&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1 2 3] tails&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1 2 3] tails&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[[]</span> <span class="p">[</span><span class="mi">3</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">3</span><span class="p">]]</span>
@@ -42,12 +42,12 @@ we can implement e.g. a function that adds new functions to the
dictionary. However, theres no function that does that. Adding a new
function to the dictionary is a meta-interpreter action, you have to do
it in Python, not Joy.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from notebook_preamble import D, J, V
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">notebook_preamble</span> <span class="kn">import</span> <span class="n">D</span><span class="p">,</span> <span class="n">J</span><span class="p">,</span> <span class="n">V</span>
</pre></div>
</div>
<section id="a-long-trace">
<h2>A long trace<a class="headerlink" href="#a-long-trace" title="Permalink to this headline"></a></h2>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;[23 18] average&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;[23 18] average&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="p">[</span><span class="mi">23</span> <span class="mi">18</span><span class="p">]</span> <span class="n">average</span>
@@ -105,30 +105,30 @@ it in Python, not Joy.</p>
<p>An efficient <code class="docutils literal notranslate"><span class="pre">sum</span></code> function is already in the library. But for
<code class="docutils literal notranslate"><span class="pre">size</span></code> we can use a “compiled” version hand-written in Python to speed
up evaluation and make the trace more readable.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from joy.library import SimpleFunctionWrapper
from joy.utils.stack import iter_stack
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">joy.library</span> <span class="kn">import</span> <span class="n">SimpleFunctionWrapper</span>
<span class="kn">from</span> <span class="nn">joy.utils.stack</span> <span class="kn">import</span> <span class="n">iter_stack</span>
@SimpleFunctionWrapper
def size(stack):
&#39;&#39;&#39;Return the size of the sequence on the stack.&#39;&#39;&#39;
sequence, stack = stack
n = 0
for _ in iter_stack(sequence):
n += 1
return n, stack
<span class="nd">@SimpleFunctionWrapper</span>
<span class="k">def</span> <span class="nf">size</span><span class="p">(</span><span class="n">stack</span><span class="p">):</span>
<span class="sd">&#39;&#39;&#39;Return the size of the sequence on the stack.&#39;&#39;&#39;</span>
<span class="n">sequence</span><span class="p">,</span> <span class="n">stack</span> <span class="o">=</span> <span class="n">stack</span>
<span class="n">n</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">for</span> <span class="n">_</span> <span class="ow">in</span> <span class="n">iter_stack</span><span class="p">(</span><span class="n">sequence</span><span class="p">):</span>
<span class="n">n</span> <span class="o">+=</span> <span class="mi">1</span>
<span class="k">return</span> <span class="n">n</span><span class="p">,</span> <span class="n">stack</span>
</pre></div>
</div>
<p>Now we replace the old version in the dictionary with the new version,
and re-evaluate the expression.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>D[&#39;size&#39;] = size
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">D</span><span class="p">[</span><span class="s1">&#39;size&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="n">size</span>
</pre></div>
</div>
</section>
<section id="a-shorter-trace">
<h2>A shorter trace<a class="headerlink" href="#a-shorter-trace" title="Permalink to this headline"></a></h2>
<p>You can see that <code class="docutils literal notranslate"><span class="pre">size</span></code> now executes in a single step.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;[23 18] average&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;[23 18] average&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="p">[</span><span class="mi">23</span> <span class="mi">18</span><span class="p">]</span> <span class="n">average</span>
@@ -148,17 +148,17 @@ the desired outcome.</p>
</section>
<section id="define-treestep">
<h2>Define <code class="docutils literal notranslate"><span class="pre">treestep</span></code><a class="headerlink" href="#define-treestep" title="Permalink to this headline"></a></h2>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from notebook_preamble import D, J, V, define, DefinitionWrapper
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">notebook_preamble</span> <span class="kn">import</span> <span class="n">D</span><span class="p">,</span> <span class="n">J</span><span class="p">,</span> <span class="n">V</span><span class="p">,</span> <span class="n">define</span><span class="p">,</span> <span class="n">DefinitionWrapper</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>DefinitionWrapper.add_definitions(&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">DefinitionWrapper</span><span class="o">.</span><span class="n">add_definitions</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
_treestep_0 == [[not] swap] dip
_treestep_1 == [dip] cons [uncons] swoncat
treegrind == [_treestep_1 _treestep_0] dip genrec
treestep == [map] swoncat treegrind
<span class="s1"> _treestep_0 == [[not] swap] dip</span>
<span class="s1"> _treestep_1 == [dip] cons [uncons] swoncat</span>
<span class="s1"> treegrind == [_treestep_1 _treestep_0] dip genrec</span>
<span class="s1"> treestep == [map] swoncat treegrind</span>
&#39;&#39;&#39;, D)
<span class="s1">&#39;&#39;&#39;</span><span class="p">,</span> <span class="n">D</span><span class="p">)</span>
</pre></div>
</div>
</section>
@@ -169,7 +169,7 @@ all nodes in a tree with this function:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">sumtree</span> <span class="o">==</span> <span class="p">[</span><span class="n">pop</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[</span><span class="nb">sum</span> <span class="o">+</span><span class="p">]</span> <span class="n">treestep</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;sumtree == [pop 0] [] [sum +] treestep&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;sumtree == [pop 0] [] [sum +] treestep&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Running this function on an empty tree value gives zero:</p>
@@ -178,7 +178,7 @@ all nodes in a tree with this function:</p>
<span class="mi">0</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[] sumtree&#39;) # Empty tree.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[] sumtree&#39;</span><span class="p">)</span> <span class="c1"># Empty tree.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">0</span>
@@ -192,61 +192,61 @@ all nodes in a tree with this function:</p>
<span class="n">n</span><span class="o">+</span><span class="n">m</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23] sumtree&#39;) # No child trees.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23] sumtree&#39;</span><span class="p">)</span> <span class="c1"># No child trees.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">23</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 []] sumtree&#39;) # Child tree, empty.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 []] sumtree&#39;</span><span class="p">)</span> <span class="c1"># Child tree, empty.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">23</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [4]] [3]] sumtree&#39;) # Non-empty child trees.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [4]] [3]] sumtree&#39;</span><span class="p">)</span> <span class="c1"># Non-empty child trees.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">32</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [8] [9]] [3] [4 []]] sumtree&#39;) # Etc...
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [8] [9]] [3] [4 []]] sumtree&#39;</span><span class="p">)</span> <span class="c1"># Etc...</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">49</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [8] [9]] [3] [4 []]] [pop 0] [] [cons sum] treestep&#39;) # Alternate &quot;spelling&quot;.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [8] [9]] [3] [4 []]] [pop 0] [] [cons sum] treestep&#39;</span><span class="p">)</span> <span class="c1"># Alternate &quot;spelling&quot;.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">49</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [8] [9]] [3] [4 []]] [] [pop 23] [cons] treestep&#39;) # Replace each node.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [8] [9]] [3] [4 []]] [] [pop 23] [cons] treestep&#39;</span><span class="p">)</span> <span class="c1"># Replace each node.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">23</span> <span class="p">[</span><span class="mi">23</span> <span class="p">[</span><span class="mi">23</span><span class="p">]</span> <span class="p">[</span><span class="mi">23</span><span class="p">]]</span> <span class="p">[</span><span class="mi">23</span><span class="p">]</span> <span class="p">[</span><span class="mi">23</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [8] [9]] [3] [4 []]] [] [pop 1] [cons] treestep&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [8] [9]] [3] [4 []]] [] [pop 1] [cons] treestep&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">1</span><span class="p">]]</span> <span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">1</span> <span class="p">[]]]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [8] [9]] [3] [4 []]] [] [pop 1] [cons] treestep sumtree&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [8] [9]] [3] [4 []]] [] [pop 1] [cons] treestep sumtree&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">6</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[23 [2 [8] [9]] [3] [4 []]] [pop 0] [pop 1] [sum +] treestep&#39;) # Combine replace and sum into one function.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[23 [2 [8] [9]] [3] [4 []]] [pop 0] [pop 1] [sum +] treestep&#39;</span><span class="p">)</span> <span class="c1"># Combine replace and sum into one function.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">6</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[4 [3 [] [7]]] [pop 0] [pop 1] [sum +] treestep&#39;) # Combine replace and sum into one function.
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[4 [3 [] [7]]] [pop 0] [pop 1] [sum +] treestep&#39;</span><span class="p">)</span> <span class="c1"># Combine replace and sum into one function.</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">3</span>
@@ -277,7 +277,7 @@ all nodes in a tree with this function:</p>
</pre></div>
</div>
<p>This doesnt quite work:</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[[3 0] [[2 0] [][]] [[9 0] [[5 0] [[4 0] [][]] [[8 0] [[6 0] [] [[7 0] [][]]][]]][]]] [&quot;B&quot;] [first] [i] treestep&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[[3 0] [[2 0] [][]] [[9 0] [[5 0] [[4 0] [][]] [[8 0] [[6 0] [] [[7 0] [][]]][]]][]]] [&quot;B&quot;] [first] [i] treestep&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">3</span> <span class="s1">&#39;B&#39;</span> <span class="s1">&#39;B&#39;</span>
@@ -299,7 +299,7 @@ depositing our results directly on the stack.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[]</span> <span class="p">[</span><span class="n">first</span><span class="p">]</span> <span class="p">[</span><span class="n">flatten</span> <span class="n">cons</span><span class="p">]</span> <span class="n">treestep</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [] [first] [flatten cons] treestep&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [] [first] [flatten cons] treestep&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">3</span> <span class="mi">2</span> <span class="mi">9</span> <span class="mi">5</span> <span class="mi">4</span> <span class="mi">8</span> <span class="mi">6</span> <span class="mi">7</span><span class="p">]</span>
@@ -322,7 +322,7 @@ depositing our results directly on the stack.</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[]</span> <span class="p">[</span><span class="n">i</span> <span class="n">roll</span><span class="o">&lt;</span> <span class="n">swons</span> <span class="n">concat</span><span class="p">]</span> <span class="p">[</span><span class="n">first</span><span class="p">]</span> <span class="n">treestep</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [] [uncons pop] [i roll&lt; swons concat] treestep&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [] [uncons pop] [i roll&lt; swons concat] treestep&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">2</span> <span class="mi">3</span> <span class="mi">4</span> <span class="mi">5</span> <span class="mi">6</span> <span class="mi">7</span> <span class="mi">8</span> <span class="mi">9</span><span class="p">]</span>
@@ -343,7 +343,7 @@ non-empty node is:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="n">key</span> <span class="n">value</span><span class="p">]</span> <span class="n">N</span> <span class="p">[</span><span class="n">left</span> <span class="n">right</span><span class="p">]</span> <span class="p">[</span><span class="n">K</span><span class="p">]</span> <span class="n">C</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[[&quot;key&quot; &quot;value&quot;] [&quot;left&quot;] [&quot;right&quot;] ] [&quot;B&quot;] [&quot;N&quot;] [&quot;C&quot;] treegrind&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[[&quot;key&quot; &quot;value&quot;] [&quot;left&quot;] [&quot;right&quot;] ] [&quot;B&quot;] [&quot;N&quot;] [&quot;C&quot;] treegrind&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="s1">&#39;key&#39;</span> <span class="s1">&#39;value&#39;</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[[</span><span class="s1">&#39;left&#39;</span><span class="p">]</span> <span class="p">[</span><span class="s1">&#39;right&#39;</span><span class="p">]]</span> <span class="p">[[</span><span class="ow">not</span><span class="p">]</span> <span class="p">[</span><span class="s1">&#39;B&#39;</span><span class="p">]</span> <span class="p">[</span><span class="n">uncons</span> <span class="p">[</span><span class="s1">&#39;N&#39;</span><span class="p">]</span> <span class="n">dip</span><span class="p">]</span> <span class="p">[</span><span class="s1">&#39;C&#39;</span><span class="p">]</span> <span class="n">genrec</span><span class="p">]</span> <span class="s1">&#39;C&#39;</span>
@@ -353,21 +353,21 @@ non-empty node is:</p>
<section id="treegrind-with-step">
<h2><code class="docutils literal notranslate"><span class="pre">treegrind</span></code> with <code class="docutils literal notranslate"><span class="pre">step</span></code><a class="headerlink" href="#treegrind-with-step" title="Permalink to this headline"></a></h2>
<p>Iteration through the nodes</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [pop] [&quot;N&quot;] [step] treegrind&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [pop] [&quot;N&quot;] [step] treegrind&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">3</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">9</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">5</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">8</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">6</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span> <span class="p">[</span><span class="mi">7</span> <span class="mi">0</span><span class="p">]</span> <span class="s1">&#39;N&#39;</span>
</pre></div>
</div>
<p>Sum the nodes keys.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;0 [[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [pop] [first +] [step] treegrind&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;0 [[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [pop] [first +] [step] treegrind&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">44</span>
</pre></div>
</div>
<p>Rebuild the tree using <code class="docutils literal notranslate"><span class="pre">map</span></code> (imitating <code class="docutils literal notranslate"><span class="pre">treestep</span></code>.)</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [] [[100 +] infra] [map cons] treegrind&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[[3 0] [[2 0] [] []] [[9 0] [[5 0] [[4 0] [] []] [[8 0] [[6 0] [] [[7 0] [] []]] []]] []]] [] [[100 +] infra] [map cons] treegrind&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[[</span><span class="mi">103</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[[</span><span class="mi">102</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[[</span><span class="mi">109</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[[</span><span class="mi">105</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[[</span><span class="mi">104</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[]]</span> <span class="p">[[</span><span class="mi">108</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[[</span><span class="mi">106</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[[</span><span class="mi">107</span> <span class="mi">0</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[]]]</span> <span class="p">[]]]</span> <span class="p">[]]]</span>
@@ -449,37 +449,37 @@ equal):</p>
</pre></div>
</div>
<p>To me, that seems simpler than the <code class="docutils literal notranslate"><span class="pre">genrec</span></code> version.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>DefinitionWrapper.add_definitions(&#39;&#39;&#39;
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">DefinitionWrapper</span><span class="o">.</span><span class="n">add_definitions</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span>
T&gt; == pop [first] dip i
T&lt; == pop [second] dip i
E == roll&gt; popop first
P == roll&lt; [roll&lt; uncons swap] dip
<span class="s1"> T&gt; == pop [first] dip i</span>
<span class="s1"> T&lt; == pop [second] dip i</span>
<span class="s1"> E == roll&gt; popop first</span>
<span class="s1"> P == roll&lt; [roll&lt; uncons swap] dip</span>
Tree-get == [P [T&gt;] [E] [T&lt;] cmp] treegrind
<span class="s1"> Tree-get == [P [T&gt;] [E] [T&lt;] cmp] treegrind</span>
&#39;&#39;&#39;, D)
<span class="s1">&#39;&#39;&#39;</span><span class="p">,</span> <span class="n">D</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;&#39;&#39;\
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span><span class="se">\</span>
[[3 13] [[2 12] [] []] [[9 19] [[5 15] [[4 14] [] []] [[8 18] [[6 16] [] [[7 17] [] []]] []]] []]]
<span class="s1">[[3 13] [[2 12] [] []] [[9 19] [[5 15] [[4 14] [] []] [[8 18] [[6 16] [] [[7 17] [] []]] []]] []]]</span>
[] [5] Tree-get
<span class="s1">[] [5] Tree-get</span>
&#39;&#39;&#39;)
<span class="s1">&#39;&#39;&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="mi">15</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;&#39;&#39;\
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;&#39;&#39;</span><span class="se">\</span>
[[3 13] [[2 12] [] []] [[9 19] [[5 15] [[4 14] [] []] [[8 18] [[6 16] [] [[7 17] [] []]] []]] []]]
<span class="s1">[[3 13] [[2 12] [] []] [[9 19] [[5 15] [[4 14] [] []] [[8 18] [[6 16] [] [[7 17] [] []]] []]] []]]</span>
[pop &quot;nope&quot;] [25] Tree-get
<span class="s1">[pop &quot;nope&quot;] [25] Tree-get</span>
&#39;&#39;&#39;)
<span class="s1">&#39;&#39;&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;nope&#39;</span>
@@ -35,33 +35,33 @@
<section id="type-checking">
<h1>Type Checking<a class="headerlink" href="#type-checking" title="Permalink to this headline"></a></h1>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>import logging, sys
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">logging</span><span class="o">,</span> <span class="nn">sys</span>
logging.basicConfig(
format=&#39;%(message)s&#39;,
stream=sys.stdout,
level=logging.INFO,
)
<span class="n">logging</span><span class="o">.</span><span class="n">basicConfig</span><span class="p">(</span>
<span class="nb">format</span><span class="o">=</span><span class="s1">&#39;</span><span class="si">%(message)s</span><span class="s1">&#39;</span><span class="p">,</span>
<span class="n">stream</span><span class="o">=</span><span class="n">sys</span><span class="o">.</span><span class="n">stdout</span><span class="p">,</span>
<span class="n">level</span><span class="o">=</span><span class="n">logging</span><span class="o">.</span><span class="n">INFO</span><span class="p">,</span>
<span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from joy.utils.types import (
doc_from_stack_effect,
infer,
reify,
unify,
FUNCTIONS,
JoyTypeError,
)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">joy.utils.types</span> <span class="kn">import</span> <span class="p">(</span>
<span class="n">doc_from_stack_effect</span><span class="p">,</span>
<span class="n">infer</span><span class="p">,</span>
<span class="n">reify</span><span class="p">,</span>
<span class="n">unify</span><span class="p">,</span>
<span class="n">FUNCTIONS</span><span class="p">,</span>
<span class="n">JoyTypeError</span><span class="p">,</span>
<span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>D = FUNCTIONS.copy()
del D[&#39;product&#39;]
globals().update(D)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">D</span> <span class="o">=</span> <span class="n">FUNCTIONS</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
<span class="k">del</span> <span class="n">D</span><span class="p">[</span><span class="s1">&#39;product&#39;</span><span class="p">]</span>
<span class="nb">globals</span><span class="p">()</span><span class="o">.</span><span class="n">update</span><span class="p">(</span><span class="n">D</span><span class="p">)</span>
</pre></div>
</div>
<section id="an-example">
<h2>An Example<a class="headerlink" href="#an-example" title="Permalink to this headline"></a></h2>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>fi, fo = infer(pop, swap, rolldown, rrest, ccons)[0]
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">fi</span><span class="p">,</span> <span class="n">fo</span> <span class="o">=</span> <span class="n">infer</span><span class="p">(</span><span class="n">pop</span><span class="p">,</span> <span class="n">swap</span><span class="p">,</span> <span class="n">rolldown</span><span class="p">,</span> <span class="n">rrest</span><span class="p">,</span> <span class="n">ccons</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>25 (--) ∘ pop swap rolldown rrest ccons
@@ -72,32 +72,32 @@ globals().update(D)
40 ([a4 a5 ...1] a3 a2 a1 -- [a2 a3 ...1]) ∘
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>print doc_from_stack_effect(fi, fo)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="nb">print</span> <span class="n">doc_from_stack_effect</span><span class="p">(</span><span class="n">fi</span><span class="p">,</span> <span class="n">fo</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">([</span><span class="n">a4</span> <span class="n">a5</span> <span class="o">...</span><span class="mi">1</span><span class="p">]</span> <span class="n">a3</span> <span class="n">a2</span> <span class="n">a1</span> <span class="o">--</span> <span class="p">[</span><span class="n">a2</span> <span class="n">a3</span> <span class="o">...</span><span class="mi">1</span><span class="p">])</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from joy.parser import text_to_expression
from joy.utils.stack import stack_to_string
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">joy.parser</span> <span class="kn">import</span> <span class="n">text_to_expression</span>
<span class="kn">from</span> <span class="nn">joy.utils.stack</span> <span class="kn">import</span> <span class="n">stack_to_string</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>e = text_to_expression(&#39;0 1 2 [3 4]&#39;) # reverse order
print stack_to_string(e)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">e</span> <span class="o">=</span> <span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;0 1 2 [3 4]&#39;</span><span class="p">)</span> <span class="c1"># reverse order</span>
<span class="nb">print</span> <span class="n">stack_to_string</span><span class="p">(</span><span class="n">e</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">3</span> <span class="mi">4</span><span class="p">]</span> <span class="mi">2</span> <span class="mi">1</span> <span class="mi">0</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>u = unify(e, fi)[0]
u
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">u</span> <span class="o">=</span> <span class="n">unify</span><span class="p">(</span><span class="n">e</span><span class="p">,</span> <span class="n">fi</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span>
<span class="n">u</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">{</span><span class="n">a1</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="n">a2</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span> <span class="n">a3</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span> <span class="n">a4</span><span class="p">:</span> <span class="mi">3</span><span class="p">,</span> <span class="n">a5</span><span class="p">:</span> <span class="mi">4</span><span class="p">,</span> <span class="n">s2</span><span class="p">:</span> <span class="p">(),</span> <span class="n">s1</span><span class="p">:</span> <span class="p">()}</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>g = reify(u, (fi, fo))
print doc_from_stack_effect(*g)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">g</span> <span class="o">=</span> <span class="n">reify</span><span class="p">(</span><span class="n">u</span><span class="p">,</span> <span class="p">(</span><span class="n">fi</span><span class="p">,</span> <span class="n">fo</span><span class="p">))</span>
<span class="nb">print</span> <span class="n">doc_from_stack_effect</span><span class="p">(</span><span class="o">*</span><span class="n">g</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">(</span><span class="o">...</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="p">]</span> <span class="mi">2</span> <span class="mi">1</span> <span class="mi">0</span> <span class="o">--</span> <span class="o">...</span> <span class="p">[</span><span class="mi">1</span> <span class="mi">2</span> <span class="p">])</span>
@@ -106,18 +106,18 @@ print doc_from_stack_effect(*g)
</section>
<section id="unification-works-in-reverse">
<h2>Unification Works “in Reverse”<a class="headerlink" href="#unification-works-in-reverse" title="Permalink to this headline"></a></h2>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>e = text_to_expression(&#39;[2 3]&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">e</span> <span class="o">=</span> <span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;[2 3]&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>u = unify(e, fo)[0] # output side, not input side
u
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">u</span> <span class="o">=</span> <span class="n">unify</span><span class="p">(</span><span class="n">e</span><span class="p">,</span> <span class="n">fo</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span> <span class="c1"># output side, not input side</span>
<span class="n">u</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">{</span><span class="n">a2</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span> <span class="n">a3</span><span class="p">:</span> <span class="mi">3</span><span class="p">,</span> <span class="n">s2</span><span class="p">:</span> <span class="p">(),</span> <span class="n">s1</span><span class="p">:</span> <span class="p">()}</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>g = reify(u, (fi, fo))
print doc_from_stack_effect(*g)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">g</span> <span class="o">=</span> <span class="n">reify</span><span class="p">(</span><span class="n">u</span><span class="p">,</span> <span class="p">(</span><span class="n">fi</span><span class="p">,</span> <span class="n">fo</span><span class="p">))</span>
<span class="nb">print</span> <span class="n">doc_from_stack_effect</span><span class="p">(</span><span class="o">*</span><span class="n">g</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">(</span><span class="o">...</span> <span class="p">[</span><span class="n">a4</span> <span class="n">a5</span> <span class="p">]</span> <span class="mi">3</span> <span class="mi">2</span> <span class="n">a1</span> <span class="o">--</span> <span class="o">...</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">3</span> <span class="p">])</span>
@@ -126,7 +126,7 @@ print doc_from_stack_effect(*g)
</section>
<section id="failing-a-check">
<h2>Failing a Check<a class="headerlink" href="#failing-a-check" title="Permalink to this headline"></a></h2>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>fi, fo = infer(dup, mul)[0]
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">fi</span><span class="p">,</span> <span class="n">fo</span> <span class="o">=</span> <span class="n">infer</span><span class="p">(</span><span class="n">dup</span><span class="p">,</span> <span class="n">mul</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>25 (--) ∘ dup mul
@@ -135,17 +135,17 @@ print doc_from_stack_effect(*g)
31 (i1 -- i2) ∘
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>e = text_to_expression(&#39;&quot;two&quot;&#39;)
print stack_to_string(e)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">e</span> <span class="o">=</span> <span class="n">text_to_expression</span><span class="p">(</span><span class="s1">&#39;&quot;two&quot;&#39;</span><span class="p">)</span>
<span class="nb">print</span> <span class="n">stack_to_string</span><span class="p">(</span><span class="n">e</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="s1">&#39;two&#39;</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>try:
unify(e, fi)
except JoyTypeError, err:
print err
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">try</span><span class="p">:</span>
<span class="n">unify</span><span class="p">(</span><span class="n">e</span><span class="p">,</span> <span class="n">fi</span><span class="p">)</span>
<span class="k">except</span> <span class="n">JoyTypeError</span><span class="p">,</span> <span class="n">err</span><span class="p">:</span>
<span class="nb">print</span> <span class="n">err</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">Cannot</span> <span class="n">unify</span> <span class="s1">&#39;two&#39;</span> <span class="ow">and</span> <span class="n">f1</span><span class="o">.</span>
File diff suppressed because it is too large Load Diff
@@ -42,7 +42,7 @@ the original paper: <a class="reference external" href="https://www.st.cs.uni-sa
Huet</a></p>
<p>Given a datastructure on the stack we can navigate through it, modify
it, and rebuild it using the “zipper” technique.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>from notebook_preamble import J, V, define
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">notebook_preamble</span> <span class="kn">import</span> <span class="n">J</span><span class="p">,</span> <span class="n">V</span><span class="p">,</span> <span class="n">define</span>
</pre></div>
</div>
<section id="trees">
@@ -52,7 +52,7 @@ strings, Symbols (strings that are names of functions) and sequences
(aka lists, aka quoted literals, aka aggregates, etc…), but we can build
<a class="reference external" href="https://en.wikipedia.org/wiki/Tree_%28data_structure%29">trees</a> out
of sequences.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1 [2 [3 4 25 6] 7] 8]&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1 [2 [3 4 25 6] 7] 8]&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span>
@@ -75,13 +75,13 @@ datastructure used to keep track of these items is the zipper.)</p>
show the trace so you can see how it works. If we were going to use
these a lot it would make sense to write Python versions for efficiency,
but see below.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;z-down == [] swap uncons swap&#39;)
define(&#39;z-up == swons swap shunt&#39;)
define(&#39;z-right == [swons] cons dip uncons swap&#39;)
define(&#39;z-left == swons [uncons swap] dip swap&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;z-down == [] swap uncons swap&#39;</span><span class="p">)</span>
<span class="n">define</span><span class="p">(</span><span class="s1">&#39;z-up == swons swap shunt&#39;</span><span class="p">)</span>
<span class="n">define</span><span class="p">(</span><span class="s1">&#39;z-right == [swons] cons dip uncons swap&#39;</span><span class="p">)</span>
<span class="n">define</span><span class="p">(</span><span class="s1">&#39;z-left == swons [uncons swap] dip swap&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;[1 [2 [3 4 25 6] 7] 8] z-down&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;[1 [2 [3 4 25 6] 7] 8] z-down&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span> <span class="n">z</span><span class="o">-</span><span class="n">down</span>
@@ -93,7 +93,7 @@ define(&#39;z-left == swons [uncons swap] dip swap&#39;)
<span class="p">[]</span> <span class="p">[[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span> <span class="mi">1</span> <span class="o">.</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;[] [[2 [3 4 25 6] 7] 8] 1 z-right&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;[] [[2 [3 4 25 6] 7] 8] 1 z-right&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="p">[]</span> <span class="p">[[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span> <span class="mi">1</span> <span class="n">z</span><span class="o">-</span><span class="n">right</span>
@@ -113,43 +113,43 @@ define(&#39;z-left == swons [uncons swap] dip swap&#39;)
<span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="o">.</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2 [3 4 25 6] 7] z-down&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2 [3 4 25 6] 7] z-down&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">2</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [] [[3 4 25 6] 7] 2 z-right&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [] [[3 4 25 6] 7] 2 z-right&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2] [7] [3 4 25 6] z-down&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2] [7] [3 4 25 6] z-down&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[]</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">3</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2] [7] [] [4 25 6] 3 z-right&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2] [7] [] [4 25 6] 3 z-right&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[</span><span class="mi">3</span><span class="p">]</span> <span class="p">[</span><span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">4</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2] [7] [3] [25 6] 4 z-right&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2] [7] [3] [25 6] 4 z-right&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">3</span><span class="p">]</span> <span class="p">[</span><span class="mi">6</span><span class="p">]</span> <span class="mi">25</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2] [7] [4 3] [6] 25 sqr&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2] [7] [4 3] [6] 25 sqr&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">3</span><span class="p">]</span> <span class="p">[</span><span class="mi">6</span><span class="p">]</span> <span class="mi">625</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;[1] [8] [2] [7] [4 3] [6] 625 z-up&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2] [7] [4 3] [6] 625 z-up&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[</span><span class="mi">4</span> <span class="mi">3</span><span class="p">]</span> <span class="p">[</span><span class="mi">6</span><span class="p">]</span> <span class="mi">625</span> <span class="n">z</span><span class="o">-</span><span class="n">up</span>
@@ -168,13 +168,13 @@ define(&#39;z-left == swons [uncons swap] dip swap&#39;)
<span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span><span class="p">]</span> <span class="p">[</span><span class="mi">7</span><span class="p">]</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">625</span> <span class="mi">6</span><span class="p">]</span> <span class="o">.</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2] [7] [3 4 625 6] z-up&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2] [7] [3 4 625 6] z-up&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="p">[</span><span class="mi">8</span><span class="p">]</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">625</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span>
</pre></div>
</div>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1] [8] [2 [3 4 625 6] 7] z-up&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1] [8] [2 [3 4 625 6] 7] z-up&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">625</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span>
@@ -185,7 +185,7 @@ define(&#39;z-left == swons [uncons swap] dip swap&#39;)
<h2><code class="docutils literal notranslate"><span class="pre">dip</span></code> and <code class="docutils literal notranslate"><span class="pre">infra</span></code><a class="headerlink" href="#dip-and-infra" title="Permalink to this headline"></a></h2>
<p>In Joy we have the <code class="docutils literal notranslate"><span class="pre">dip</span></code> and <code class="docutils literal notranslate"><span class="pre">infra</span></code> combinators which can “target”
or “address” any particular item in a Joy tree structure.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;[1 [2 [3 4 25 6] 7] 8] [[[[[[sqr] dipd] infra] dip] infra] dip] infra&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;[1 [2 [3 4 25 6] 7] 8] [[[[[[sqr] dipd] infra] dip] infra] dip] infra&#39;</span><span class="p">)</span>
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<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">25</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span> <span class="p">[[[[[[</span><span class="n">sqr</span><span class="p">]</span> <span class="n">dipd</span><span class="p">]</span> <span class="n">infra</span><span class="p">]</span> <span class="n">dip</span><span class="p">]</span> <span class="n">infra</span><span class="p">]</span> <span class="n">dip</span><span class="p">]</span> <span class="n">infra</span>
@@ -236,11 +236,11 @@ been embedded in a nested series of quoted programs, e.g.:</p>
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<p>The <code class="docutils literal notranslate"><span class="pre">Z</span></code> function isnt hard to make.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>define(&#39;Z == [[] cons cons] step i&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">define</span><span class="p">(</span><span class="s1">&#39;Z == [[] cons cons] step i&#39;</span><span class="p">)</span>
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<p>Here it is in action in a simplified scenario.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>V(&#39;1 [2 3 4] Z&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">V</span><span class="p">(</span><span class="s1">&#39;1 [2 3 4] Z&#39;</span><span class="p">)</span>
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<div class="highlight-default notranslate"><div class="highlight"><pre><span></span> <span class="o">.</span> <span class="mi">1</span> <span class="p">[</span><span class="mi">2</span> <span class="mi">3</span> <span class="mi">4</span><span class="p">]</span> <span class="n">Z</span>
@@ -273,7 +273,7 @@ been embedded in a nested series of quoted programs, e.g.:</p>
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<p>And here it is doing the main thing.</p>
<div class="highlight-ipython2 notranslate"><div class="highlight"><pre><span></span>J(&#39;[1 [2 [3 4 25 6] 7] 8] [sqr] [dip dip infra dip infra dip infra] Z&#39;)
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">J</span><span class="p">(</span><span class="s1">&#39;[1 [2 [3 4 25 6] 7] 8] [sqr] [dip dip infra dip infra dip infra] Z&#39;</span><span class="p">)</span>
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<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span> <span class="p">[</span><span class="mi">2</span> <span class="p">[</span><span class="mi">3</span> <span class="mi">4</span> <span class="mi">625</span> <span class="mi">6</span><span class="p">]</span> <span class="mi">7</span><span class="p">]</span> <span class="mi">8</span><span class="p">]</span>