built-in method
context/1
Description
context(Context)
Returns the execution context for a predicate clause using the term
logtalk(Head,ExecutionContext) where Head is the head of the
clause containing the call. This private predicate is mainly used for
providing an error context when type-checking predicate arguments. The
ExecutionContext term should be regarded as an opaque term, which
can be decoded using the
logtalk::execution_context/7
predicate. Calls to this predicate are inlined at compilation time.
Warning
As the execution context term includes the clause head, the head
of the clause calling the context(Context) method cannot contain
the Context variable as that would result in the creation of
a cyclic term. The compiler detects and reports any offending
clauses by throwing a representation_error(acyclic_term) error.
Modes and number of proofs
context(--callable) - one
Errors
(none)
Examples
foo(A, N) :-
% type-check arguments
context(Context),
type::check(atom, A, Context),
type::check(integer, N, Context),
% arguments are fine; go ahead
... .
See also