Bumped version to 0.2.0; docs edits.

I've added cond and cmp to the library so that should bump the minor
version no. I think.

docs/Treestep.ipynb

@@ -4,8 +4,8 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Treating Trees II\n",
-    "Let's consider a tree structure, similar to one described [\"Why functional programming matters\" by John Hughes](https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf), that consists of a node value followed by a sequence of zero or more child trees.  (The asterisk is meant to indicate the [Kleene star](https://en.wikipedia.org/wiki/Kleene_star).)\n",
+    "# Treating Trees II: `treestep`\n",
+    "Let's consider a tree structure, similar to one described [\"Why functional programming matters\" by John Hughes](https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf), that consists of a node value followed by zero or more child trees.  (The asterisk is meant to indicate the [Kleene star](https://en.wikipedia.org/wiki/Kleene_star).)\n",
     "\n",
     "    tree = [] | [node tree*]"
    ]
@@ -14,7 +14,6 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## `treestep`\n",
     "In the spirit of `step` we are going to define a combinator `treestep` which expects a tree and three additional items: a base-case function `[B]`, and two quoted programs `[N]` and `[C]`.\n",
     "\n",
     "    tree [B] [N] [C] treestep"
@@ -829,42 +828,6 @@
    "cell_type": "code",
    "execution_count": 23,
    "metadata": {},
-   "outputs": [],
-   "source": [
-    "from joy.library import FunctionWrapper\n",
-    "from joy.utils.stack import pushback\n",
-    "\n",
-    "\n",
-    "@FunctionWrapper\n",
-    "def cmp_(stack, expression, dictionary):\n",
-    "    '''\n",
-    "    cmp takes two values and three quoted programs on the stack and runs\n",
-    "    one of the three depending on the results of comparing the two values:\n",
-    "\n",
-    "           a b [G] [E] [L] cmp\n",
-    "        ------------------------- a > b\n",
-    "                G\n",
-    "\n",
-    "           a b [G] [E] [L] cmp\n",
-    "        ------------------------- a = b\n",
-    "                    E\n",
-    "\n",
-    "           a b [G] [E] [L] cmp\n",
-    "        ------------------------- a < b\n",
-    "                        L\n",
-    "    '''\n",
-    "    L, (E, (G, (b, (a, stack)))) = stack\n",
-    "    expression = pushback(G if a > b else L if a < b else E, expression)\n",
-    "    return stack, expression, dictionary\n",
-    "\n",
-    "\n",
-    "D['cmp'] = cmp_"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 24,
-   "metadata": {},
    "outputs": [
     {
      "name": "stdout",
@@ -886,7 +849,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": 24,
    "metadata": {},
    "outputs": [
     {
@@ -906,13 +869,6 @@
     "\n",
     "''')"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {