%% @file yapi.yap
%% @brief support yap shell
%%
:- module(yapi, [query/3]).

:- use_module( library(lists) ).
:- use_module( library(maplist) ).
:- use_module( library(rbtrees) ).


%% @pred yap_query(0:Goal, + VarList, +OutStream, - Dictionary)
%% @pred yap_query(0:Goal, + VarList, - Dictionary)
%%
%% dictionary, Examples
%%
%%
yap_query( Goal, VarNames, Stream, Dictionary) :-
	(
        call(Goal)
        *->
	constraints(VarNames, Goal, Stream, Dictionary)
    ).

prolog:yap_query( Goal, VarNames, Dictionary) :-
        yap_query( Goal, VarNames, user_output, Dictionary).

constraints(QVs, Goal, Stream, {Dict}) :-
		 !,
	term_variables(Goal, IVs),
	foldl(enumerate, IVs, 0, _Ns),
        out(QVs, Stream, Dict).
constraints(_, _, {}) :-
     format(' yes.~n', [] ).

bind_qv(V=V0, Vs, Vs) :- var(V0), !, V0='$VAR'(V).
bind_qv(V=V, Vs, Vs) :- !.
bind_qv(V=S, Vs, [V=S|Vs]).

enumerate('$VAR'(A), I, I1) :-
	enum(I, Chars),
	atom_codes(A,[0'_|Chars]),
	I1 is I + 1.

enum(I, [C]) :-
	I < 26,
     !, C is "A" + I.
enum(I, [C|Cs]) :-
	J is I//26,
	K is I mod 26,
	C is "A" +K,
	enum(J, Cs).

out(Bs, S, _Dict) :-
	output(Bs, S),
	fail.
out(Bs, _S, Dict) :-
	bvs(Bs, Dict).

v2py(v(I0) = _V, I0, I) :-
	!,
	I is I0+1.
v2py(v(I0) = v(I0), I0, I) :-
    I is I0+1.

output([V=B], S) :-
		format(S, 'a = ~q~n', [V, B]).
output([V=B|Ns], S) :-
		format( S, 'a = ~q.~n', [V, B]),
		output( Ns, S).


		bvs([V=B],{V:B}) :-
			!.
		bvs([V=B|Ns], (V:B,N)) :-
				output( Ns, N).
:- start_low_level_trace.