Hiding shift/reset on tracing

Help!
1

I am still somehow working on ZDD which is based on
term_hash/functor/setarg/shift/reset.
Shift/reset are convenient to run prolog
query hyding state on ZDD like this, where zdd/1 is a small predicate defined below.

% ?- zdd((X<<pow([a,b,c,d]), zdd_dump, card(X, C))).
%@ 2 = t(d,1,1)
%@ 3 = t(c,2,2)
%@ 4 = t(b,3,3)
%@ 5 = t(a,4,4)
%@ X = 5,

% ?- zdd((X<<[a,b,c,d], zdd_dump, card(X, C))).
%@ 2 = t(d,0,1)
%@ 3 = t(c,0,2)
%@ 4 = t(b,0,3)
%@ 5 = t(a,0,4)
%@ X = 5,
%@ C = 1.

Is there a way to skip shift/reset on tracing ?
Although shift/reset are useful, but, on debugging,
usually I need not see information on shift/reset. So.
I want to skip shift/reset on tracing. However it seems
no way to skip them even when typing ā€œlā€ for leashing.
Here is an example on such tracing. Thank you for help.

Kuniaki

%@ % Spy point on zdd:zdd/1
%@ % Spy point on zdd:zdd/3

% ?- zdd(cofact(I, t(a, 1, 0))).

%@ ^* Call: (10) zdd:zdd(zdd:cofact(_10866, t(a, 1, 0))) ? creep
%@    Call: (11) zdd_array:init_state(_11696) ? skip
%@    Exit: (11) zdd_array:init_state(..) ? creep
%@ ^  Call: (11) context_module(_11984) ? skip
%@ ^  Exit: (11) context_module(zdd) ? creep
%@  * Call: (11) zdd:zdd(zdd:cofact(_10866, t(a, 1, 0)), .., zdd) ? creep
%@  * Call: (12) zdd:zdd(cofact(_10866, t(a, 1, 0)), .., zdd) ? creep
%@ ^  Call: (13) reset(zdd:cofact(_10866, t(a, 1, 0)), _12176, _12178) ? creep
%@    Call: (14) zdd:cofact(_10866, t(a, 1, 0)) ? creep
%@    Call: (15) shift(cofact(_10866, t(a, 1, 0))) ? creep
%@    Call: (13) var(cofact(_10866, t(a, 1, 0))) ? creep
%@    Fail: (13) var(cofact(_10866, t(a, 1, 0))) ? creep
%@  * Redo: (12) zdd:zdd(cofact(_10866, t(a, 1, 0)), .., zdd) ? creep
%@ ^  Call: (13) call(zdd:cofact(_10866, t(a, 1, 0)), ..) ? creep
%@    Call: (14) zdd:cofact(_10866, t(a, 1, 0), ..) ? creep
%@    Call: (15) var(_10866) ? creep
%@    Exit: (15) var(_10866) ? creep
%@    Call: (15) _10866=1 ? creep
%@    Exit: (15) 1=1 ? creep
%@    Exit: (14) zdd:cofact(1, t(a, 1, 0), ..) ? creep
%@ ^  Exit: (13) call(zdd:cofact(1, t(a, 1, 0)), ..) ? creep
%@  * Call: (13) zdd:zdd(cont(..), .., zdd) ? creep
%@ ^  Call: (14) reset(zdd:cont(..), _12892, _12894) ? creep
%@ ^  Exit: (14) reset(zdd:cont(..), _12892, 0) ? creep
%@    Call: (14) var(_12892) ? creep
%@    Exit: (14) var(_12892) ? creep
%@    Call: (14) true ? creep
%@    Exit: (14) true ? creep
%@  * Call: (14) zdd:zdd(0, .., zdd) ? creep
%@  * Exit: (14) zdd:zdd(0, .., zdd) ? creep
%@  * Exit: (13) zdd:zdd(cont(..), .., zdd) ? creep
%@  * Exit: (12) zdd:zdd(cofact(1, t(a, 1, 0)), .., zdd) ? creep
%@  * Exit: (11) zdd:zdd(zdd:cofact(1, t(a, 1, 0)), .., zdd) ? creep
%@ ^* Exit: (10) zdd:zdd(zdd:cofact(1, t(a, 1, 0))) ? creep
%@ I = 1.

:- meta_predicate zdd(:).
zdd(E):- init_state(S), context_module(M), zdd(E, S, M).
%
zdd((A,B), S, M):-!, zdd(A, S, M), zdd(B, S, M).
zdd(X<<E, S, _):-!, zdd_eval(E, X, S).
zdd(M:G, S, _):-!, zdd(G, S, M).
zdd(0, _, _):-!.
zdd(true, _, _):-!.
zdd({G}, _, _):-!, call(G).
zdd((A;B), S, M):-!, (zdd(A, S, M); zdd(B, S, M)).
zdd((A->B), S, M):-!, (zdd(A, S, M)->zdd(B, S, M)).
zdd(Cont, S, M):- reset(M:Cont, Ball, Cont0),
	(	var(Ball) -> true
	;	call(Ball, S)
	),
	zdd(Cont0, S, M).
2

So I read your question this morning and it stuck in my mind with no idea of how to solve it.

Then in searching GitHub for code examples for another problem found this which uses $hide. Obviously the next question is what does $hide do, well it is not documented so searching the GitHub SWI-Prolog source code one finds this.

Specify that the predicate cannot be seen in the debugger.

HTH

1 Like
3

Thank you for taking time to make search on GitHub. As system
predicates such like =/2, call/N are not allowed to have spy
points, it is rather strange for me why the system predicates
shift/reset pause even when no spy points are specified. It
would be convenient for users on debugging to have a control over
for not to see such lenghty but useless infomation shown by
shift/reset.

Kuniaki Mukai