- See also
library(terms) provides similar predicates and is probably
more wide-spread than this library.
This is a SWI-Prolog implementation of the corresponding Quintus
library, based on the generalised arg/3
predicate of SWI-Prolog.
- [semidet]contains_term(+Sub,
+Term)
- Succeeds if Sub is contained in Term (=,
deterministically)
- [det]contains_var(+Sub,
+Term)
- Succeeds if Sub is contained in Term (==,
deterministically)
- free_of_term(+Sub,
+Term)
- Succeeds of Sub does not unify to any subterm of Term
- free_of_var(+Sub,
+Term)
- Succeeds of Sub is not equal (
==) to any subterm
of Term
- occurrences_of_term(+SubTerm,
+Term, ?Count)
- Count the number of SubTerms in Term
- occurrences_of_var(+SubTerm,
+Term, ?Count)
- Count the number of SubTerms in Term
- sub_term(-Sub,
+Term)
- Generates (on backtracking) all subterms of Term.
- sub_var(-Sub,
+Term)
- Generates (on backtracking) all subterms (
==) of Term.
- [det]sub_term_shared_variables(+Sub,
+Term, -Vars)
- If Sub is a sub term of Term, Vars is
bound to the list of variables in Sub that also appear
outside Sub in Term. Note that if Sub
appears twice in Term, its variables are all considered
shared.
An example use-case is refactoring a large clause body by introducing
intermediate predicates. This predicate can be used to find the
arguments that must be passed to the new predicate.
