add term variables

2018-09-24 23:33:47 -06:00
parent 5e30fa6264
commit 4cf1aa0d8f
6 changed files with 70 additions and 33 deletions
--- a/src/prolog/lib/terms.pl
+++ b/src/prolog/lib/terms.pl
@@ -0,0 +1,19 @@
+:- module(terms, [term_variables/2, numbervars/2, numbervars/3]).
+
+term_variables(Term, Vars) :- '$term_variables'(Term, Vars).
+
+numbervars(Term, N) :-
+    integer(N),
+    term_variables(Term, Vars),
+    numberlist(Vars, N, N1).
+    
+numbervars(Term, N0, N) :-
+    integer(N0),
+    integer(N),
+    term_variables(Term, Vars),
+    numberlist(Vars, N0, N).
+
+numberlist([], N,N).
+numberlist(['$VAR'(N0)|Vars], N0,N) :-
+   N1 is N0+1,
+   numberlist(Vars, N1,N).