rishi/scryer-prolog
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ADDED: term_si/1, true for terms

Browse Source 
One use case is to ensure that once/1 is safe to use:

    term_si(Goal),
    once(Goal)

In such cases, Goal is ground and can yield at most one solution,
therefore once/1 does not remove any solutions.
This commit is contained in:
Markus Triska
2023-11-29 21:24:54 +01:00
parent de452bb2c2
commit 8cb4dfef62
1 changed files with 6 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
src/lib/si.pl
View File

@@ -37,6 +37,7 @@
atomic_si/1, atomic_si/1,
list_si/1, list_si/1,
character_si/1, character_si/1,
term_si/1,
chars_si/1, chars_si/1,
dif_si/2]). dif_si/2]).
@@ -68,6 +69,11 @@ character_si(Ch) :-
atom(Ch), atom(Ch),
atom_length(Ch,1). atom_length(Ch,1).
term_si(Term) :-
( ground(Term) -> acyclic_term(Term)
; throw(error(instantiation_error, term_si/1))
).
chars_si(Chs0) :- chars_si(Chs0) :-
'$skip_max_list'(_,_, Chs0,Chs), '$skip_max_list'(_,_, Chs0,Chs),
( nonvar(Chs) -> Chs == [] ; true ), % fails for infinite lists too ( nonvar(Chs) -> Chs == [] ; true ), % fails for infinite lists too