minor cleanup

thun/gnu-prolog/fork.pl

@@ -1,9 +1,31 @@
+/*
+    Copyright 2019 Simon Forman
+
+    This file is part of Thun
+
+    Thun is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Thun is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Thun.  If not see <http://www.gnu.org/licenses/>.
+
+A fork function that actually forks.  Experimental.
+
+*/
 :- multifile(func/3).
 
 func(fork, [F, G|S], [X, Y|S]) :-
     fork(F, S, R, ChildPID), % Send F off to the child,
     thun(G, S, [Y|_]),       % Run G locally,
     read_pipe(R, X),         % Collect the result from F,
+    % FIXME deal with X=timeout...
     wait(ChildPID, Status).  % FIXME check status!!!
 
 fork(Expr, Stack, In, ChildPID) :-