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yap-6.3/CLPBN/clpbn/utils.yap
2007-07-13 00:52:54 +00:00

105 lines
3.3 KiB
Prolog

:- module(clpbn_utils, [
clpbn_not_var_member/2,
clpbn_var_member/2,
check_for_hidden_vars/3,
sort_vars_by_key/3,
sort_vars_by_key_and_parents/3]).
%
% It may happen that variables from a previous query may still be around.
% and be used in the next evaluation, so we cannot trust the list of *new*
% variables.
%
check_for_hidden_vars([], _, []).
check_for_hidden_vars([V|Vs], AllVs0, [V|NVs]) :-
check_for_extra_variables(V,AllVs0, AllVs, Vs, IVs),
check_for_hidden_vars(IVs, AllVs, NVs).
check_for_extra_variables(V,AllVs0, AllVs, Vs, IVs) :-
var(V),
clpbn:get_atts(V, [dist(_,[V1|LV])]), !,
add_old_variables([V1|LV], AllVs0, AllVs, Vs, IVs).
check_for_extra_variables(_,AllVs, AllVs, Vs, Vs).
add_old_variables([], AllVs, AllVs, Vs, Vs).
add_old_variables([V1|LV], AllVs0, AllVs, Vs, IVs) :-
clpbn_not_var_member(AllVs0, V1), !,
add_old_variables(LV, [V1|AllVs0], AllVs, [V1|Vs], IVs).
add_old_variables([_|LV], AllVs0, AllVs, Vs, IVs) :-
add_old_variables(LV, AllVs0, AllVs, Vs, IVs).
clpbn_var_member([V1|_], V) :- V1 == V, !.
clpbn_var_member([_|Vs], V) :-
clpbn_var_member(Vs, V).
clpbn_not_var_member([], _).
clpbn_not_var_member([V1|Vs], V) :- V1 \== V,
clpbn_not_var_member(Vs, V).
sort_vars_by_key(AVars, SortedAVars, UnifiableVars) :-
get_keys(AVars, KeysVars),
keysort(KeysVars, KVars),
merge_same_key(KVars, SortedAVars, [], UnifiableVars).
get_keys([], []).
get_keys([V|AVars], [K-V|KeysVars]) :-
clpbn:get_atts(V, [key(K)]), !,
get_keys(AVars, KeysVars).
get_keys([_|AVars], KeysVars) :- % may be non-CLPBN vars.
get_keys(AVars, KeysVars).
merge_same_key([], [], _, []).
merge_same_key([K1-V1,K2-V2|Vs], SortedAVars, Ks, UnifiableVars) :-
K1 == K2, !, V1 = V2,
merge_same_key([K1-V1|Vs], SortedAVars, Ks, UnifiableVars).
merge_same_key([K1-V1,K2-V2|Vs], [V1|SortedAVars], Ks, [K1|UnifiableVars]) :-
(in_keys(K1, Ks) ; \+ \+ K1 == K2), !,
add_to_keys(K1, Ks, NKs),
merge_same_key([K2-V2|Vs], SortedAVars, NKs, UnifiableVars).
merge_same_key([K-V|Vs], [V|SortedAVars], Ks, UnifiableVars) :-
add_to_keys(K, Ks, NKs),
merge_same_key(Vs, SortedAVars, NKs, UnifiableVars).
in_keys(K1,[K|_]) :- \+ \+ K1 = K, !.
in_keys(K1,[_|Ks]) :-
in_keys(K1,Ks).
add_to_keys(K1, Ks, Ks) :- ground(K1), !.
add_to_keys(K1, Ks, [K1|Ks]).
sort_vars_by_key_and_parents(AVars, SortedAVars, UnifiableVars) :-
get_keys_and_parents(AVars, KeysVars),
keysort(KeysVars, KVars),
merge_same_key(KVars, SortedAVars, [], UnifiableVars).
get_keys_and_parents([], []).
get_keys_and_parents([V|AVars], [K-V|KeysVarsF]) :-
clpbn:get_atts(V, [key(K),dist(Id,Parents)]), !,
add_parents(Parents,V,Id,KeysVarsF,KeysVars0),
get_keys_and_parents(AVars, KeysVars0).
get_keys_and_parents([_|AVars], KeysVars) :- % may be non-CLPBN vars.
get_keys_and_parents(AVars, KeysVars).
add_parents(Parents,_,_,KeyVars,KeyVars) :-
all_vars(Parents), !.
add_parents(Parents,V,Id,KeyVarsF,KeyVars0) :-
transform_parents(Parents,NParents,KeyVarsF,KeyVars0),
clpbn:put_atts(V, [dist(Id,NParents)]).
all_vars([]).
all_vars([P|Parents]) :-
var(P),
all_vars(Parents).
transform_parents([],[],KeyVars,KeyVars).
transform_parents([P|Parents0],[P|NParents],KeyVarsF,KeyVars0) :-
var(P), !,
transform_parents(Parents0,NParents,KeyVarsF,KeyVars0).
transform_parents([P|Parents0],[V|NParents],[P-V|KeyVarsF],KeyVars0) :-
transform_parents(Parents0,NParents,KeyVarsF,KeyVars0).