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portray_term(?Term, -TransTerm, +As)

Apply portray (write) transformations to Term
Term
A term.
TransTerm
A variable.
As
One of the atoms 'term', 'goal' or 'clause'

Description

Applies portray-transformations to Term, if any are visible in the caller module. If no transformation is visible, TransTerm is identical to Term.

This predicate is intended mainly for testing purposes, because portray-transformations are normally performed implicitly by the term output predicates write/1,2, writeln/1,2, print/1,2, display/1,2, printf/2,3 or write_term/2,3.

Modes and Determinism

Modules

This predicate is sensitive to its module context (tool predicate, see @/2).

Examples

    % Given the program:

	:- local portray(s/1, tr_s/2, []).
	tr_s(0, 0).
	tr_s(s(S), N) :- tr_s(S, N1), N is N1+1.


    % Implicit portray transformation by write/1:
    ?- S = s(s(s(0))), write(S).
    3
    yes.

    % Explicit portray transformation
    % Note: no transformation done by writeq/1
    ?- S = s(s(s(0))), writeq(S), portray_term(S, P, term), writeq(P).
    s(s(s(0)))
    3
    yes.

See Also

portray / 3, expand_clause / 2, expand_goal / 2, expand_macros / 2