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add variant_hash and is_non_variant to fix setof/3, bagof/3

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This commit is contained in:
Mark Thom
2025-12-12 18:05:47 -08:00
parent 29cd80510b
commit 6284aa3a3f
12 changed files with 248 additions and 143 deletions
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59
src/lib/builtins.pl
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@@ -956,54 +956,6 @@ set_difference([], _, []) :- !.
set_difference(Xs, [], Xs).
% variant/2 checks whether X is a variant of Y per the definition in
% 7.1.6.1 of the ISO standard.
:- non_counted_backtracking variant/4.
variant(X,Y,VPs,VPs0) :-
( var(X) ->
var(Y),
VPs = [X-Y|VPs0]
; var(Y) ->
false
; X =.. [FX | XArgs],
Y =.. [FX | YArgs],
lists:foldl('$call'(builtins:variant), XArgs, YArgs, VPs, VPs0)
).
:- non_counted_backtracking variant/2.
singleton([_]).
variant(X, Y) :-
variant(X,Y, VPs, []),
keysort(VPs, SVPs),
pairs:group_pairs_by_key(SVPs, SVPKs),
pairs:pairs_values(SVPKs, Vals),
lists:maplist('$call'(builtins:term_variables), Vals, Vs),
lists:maplist('$call'(builtins:singleton), Vs),
term_variables(Vs, YVars),
lists:length(SVPKs, N),
lists:length(YVars, N).
:- non_counted_backtracking group_by_variant/4.
group_by_variant([V2-S2 | Pairs], V1-S1, [S2 | Solutions], Pairs0) :-
variant(V1, V2),
!,
V1 = V2,
group_by_variant(Pairs, V2-S2, Solutions, Pairs0).
group_by_variant(Pairs, _, [], Pairs).
:- non_counted_backtracking group_by_variants/2.
group_by_variants([V-S|Pairs], [V-Solution|Solutions]) :-
group_by_variant([V-S|Pairs], V-S, Solution, Pairs0),
group_by_variants(Pairs0, Solutions).
group_by_variants([], []).
:- non_counted_backtracking iterate_variants/3.
iterate_variants([V-Solution|GroupSolutions], V, Solution) :-
@@ -1074,9 +1026,8 @@ bagof(Template, Goal, Solution) :-
term_variables(Goal, GoalVars),
term_variables(TemplateVars+GoalVars, TGVs),
lists:append(TemplateVars, Witnesses0, TGVs),
findall_with_existential(Template, Goal, PairedSolutions0, Witnesses0, Witnesses),
keysort(PairedSolutions0, PairedSolutions),
group_by_variants(PairedSolutions, GroupedSolutions),
findall_with_existential(Template, Goal, PairedSolutions, Witnesses0, Witnesses),
'$group_by_variant'(PairedSolutions, GroupedSolutions),
iterate_variants(GroupedSolutions, Witnesses, Solution).
:- non_counted_backtracking iterate_variants_and_sort/3.
@@ -1090,7 +1041,6 @@ iterate_variants_and_sort([V-Solution0|GroupSolutions], V, Solution) :-
iterate_variants_and_sort([_|GroupSolutions], Ws, Solution) :-
iterate_variants_and_sort(GroupSolutions, Ws, Solution).
:- meta_predicate(setof(?, 0, ?)).
:- non_counted_backtracking setof/3.
@@ -1112,9 +1062,8 @@ setof(Template, Goal, Solution) :-
term_variables(Goal, GoalVars),
term_variables(TemplateVars+GoalVars, TGVs),
lists:append(TemplateVars, Witnesses0, TGVs),
findall_with_existential(Template, Goal, PairedSolutions0, Witnesses0, Witnesses),
'$keysort_with_constant_var_ordering'(PairedSolutions0, PairedSolutions), % see 7.2.1
group_by_variants(PairedSolutions, GroupedSolutions),
findall_with_existential(Template, Goal, PairedSolutions, Witnesses0, Witnesses),
'$group_by_variant'(PairedSolutions, GroupedSolutions),
iterate_variants_and_sort(GroupedSolutions, Witnesses, Solution).
% Clause retrieval and information.