:/2 (colon)
Module: builtins
:/2 — calls a goal in the specified module
FORMS
Module : Goal
DESCRIPTION
‘Module’ should be instantiated to a name of a an existing, loaded module, and Goal should be instantiated to a non-variable term. The Goal will be executed as if the call to Goal appeared in the module named Module. Any module-dependent procedures such as assert/1 or retract/1 will operate on the procedures defined in Module. Any cuts appearing in Goal will cut back through the head of the clause that contained the call to :/2.
EXAMPLES
?- listing.
% behavior:eats_linguini/1
eats_linguini(mike).
eats_linguini(jane).
% behavior:eats_salad/1
eats_salad(phil).
yes.
?- eats_linguini(mike).
Error: Operation attempted on object of type procedure which does not exist.
Operation attempted on: user:eats_linguini(mike).
- Goal: user:eats_linguini(mike)
- Throw pattern: error(existence_error(procedure,user:eats_linguini(mike)),
[user:eats_linguini(mike)])
?- behavior:eats_linguini(mike).
yes.
?- builtins:setof(Person, behavior:eats_linguini(Person), Persons).
Person=Person
Persons=[jane,mike]
yes.
?- behavior:setof(Person, eats_linguini(Person), Persons).
Person=Person
Persons=[jane,mike]
yes.
ERRORS
If Module is unbound or not bound to a valid module name, the call to :/2 will fail.