expand_term(Term, Expansion)
Expands a term. The most common use is to expand a grammar rule into a clause. Users may override the default Logtalk grammar rule translator by defining clauses for the predicate term_expansion/2
.
The expansion works as follows: if the first argument is a variable, then it is unified with the second argument; if the first argument is not a variable and clauses for the term_expansion/2
predicate are within scope, then this predicate is called to provide an expansion that is then unified with the second argument; if the term_expansion/2
predicate is not used and the first argument is a compound term with functor -->/2
then the default Logtalk grammar rule translator is used, with the resulting clause being unified with the second argument; when the translator is not used, the two arguments are unified.
This built-in method may be used to expand a grammar rule into a clause for use with the built-in database methods.
expand_term(?term, ?term)