Macro swipl_macros::pred

pred!() { /* proc-macro */ }

Generate an inline callable predicate.

Predicates are specified in prolog style. You can either use the syntax predicate/arity or module:predicate/arity.

This macro will generate code that generates a CallablePredicate object. The actual prolog predicate is only looked up at first call of this generated code. Each subsequent call will reuse the lookup.

example:

let writeq = pred!(writeq/1);
context.call_once(writeq, [&term])?;

context.call_once(pred!(user:nl/0), [])?;