Daniel@0: /* Part of DML (Digital Music Laboratory)
Daniel@0: 	Copyright 2014-2015 Samer Abdallah, University of London
Daniel@0: 	 
Daniel@0: 	This program is free software; you can redistribute it and/or
Daniel@0: 	modify it under the terms of the GNU General Public License
Daniel@0: 	as published by the Free Software Foundation; either version 2
Daniel@0: 	of the License, or (at your option) any later version.
Daniel@0: 
Daniel@0: 	This program is distributed in the hope that it will be useful,
Daniel@0: 	but WITHOUT ANY WARRANTY; without even the implied warranty of
Daniel@0: 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Daniel@0: 	GNU General Public License for more details.
Daniel@0: 
Daniel@0: 	You should have received a copy of the GNU General Public
Daniel@0: 	License along with this library; if not, write to the Free Software
Daniel@0: 	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
Daniel@0: */
Daniel@0: 
Daniel@0: :- module(jpath, [ jpath/2, op(600,xfy,#) ]).
Daniel@0: :- use_module(library(dcg_core)).
Daniel@0: :- use_module(library(insist)).
Daniel@0: 
Daniel@0: % :- op(600,fx,#).
Daniel@0: :- op(600,xfy,#).
Daniel@0: 
Daniel@0: % harvest(M,Tree) :- harvest(M,just(Tree),nothing).
Daniel@0: % harvest(\X,just(X),nothing).
Daniel@0: % harvest(@F,just(X),just(Y)) :- Y=X.F.
Daniel@0: % harvest(#N,just(X),just(Y)) :- nth1(N,X,Y).
Daniel@0: % harvest(F*G) --> harvest(F), harvest(G).
Daniel@0: % harvest((F//G)) --> harvest(F) // harvest(G).
Daniel@0: 
Daniel@0: % dec(id,X,X).
Daniel@0: % dec([],_,[]).
Daniel@0: % dec([D|Ds],X,[Y|Ys]) :- dec(D,X,Y), dec(Ds,X,Ys).
Daniel@0: % dec(@F,X,Y) :- Y=X.F.
Daniel@0: % dec(F*G,X,Z) :- dec(F,X,Y), dec(G,Y,Z).
Daniel@0: % dec(swap,(X,Y),(Y,X)).
Daniel@0: % dec(dup,X,(X,X)).
Daniel@0: % dec(fst(F),(X,Y),(Z,Y)) :- dec(F,X,Z).
Daniel@0: % dec((F,G),X,(Y,Z)) :- dec(F,X,Y), dec(G,X,Z).
Daniel@0: % dec(item,X,Y) :- member(Y,X).
Daniel@0: 
Daniel@0: % decode(F, R, X) :- atomic(F), X=R.F.
Daniel@0: % decode(item(D), R, X) :- decode(D,R,Y), member(X,Y).
Daniel@0: % decode(F/G, R, X) :- decode(F,R,Y), decode(G,Y,X).
Daniel@0: 
Daniel@0: jpath(Y,X) :- 
Daniel@0:    (complex(X) -> (match(Y,X); Y=(_,_), multi_match(Y,[],X)) ; Y=X).
Daniel@0: 
Daniel@0: complex(X) :- is_list(X).
Daniel@0: complex(X) :- is_dict(X).
Daniel@0: 
Daniel@0: match(\X,X).
Daniel@0: match(Y,X) :- var(Y), !, 
Daniel@0:    (  is_dict(X) -> match_dict(Y,X)
Daniel@0:    ;  is_list(X) -> match_list(Y,X)
Daniel@0:    ).
Daniel@0: match(dict(X),X) :- must_be(dict,X).
Daniel@0: match(list(X),X) :- must_be(list,X).
Daniel@0: match(N#Y,X) :- must_be(list,X), match_member(N,Y,X).
Daniel@0: match(F:Y,X) :- must_be(dict,X), match_field(F,Y,X).
Daniel@0: 
Daniel@0: match_dict(dict(X),X).
Daniel@0: match_dict(F:V,X) :- match_field(F,V,X).
Daniel@0: 
Daniel@0: match_list(list(X),X).
Daniel@0: match_list(N#Y,X) :- match_member(N,Y,X).
Daniel@0: 
Daniel@0: match_field(F,Y,X) :- 
Daniel@0:    (  var(F) -> get_dict(F,X,Z)
Daniel@0:    ;  insist(get_dict(F,X,Z),field_not_present(F,X))
Daniel@0:    ), 
Daniel@0:    jpath(Y,Z).
Daniel@0: 
Daniel@0: match_member(N,Y,X) :- 
Daniel@0:    (  var(N) -> nth1(N,X,Z)
Daniel@0:    ;  nth1(N,X,Z) % insist(...),index_out_of_range(N,X))
Daniel@0:    ),
Daniel@0:    jpath(Y,Z).
Daniel@0: 
Daniel@0: % multi_match([],_,_).
Daniel@0: % multi_match([S|Ss],Prev,X) :- match1(S,X), \+member(S,Prev), multi_match(Ss,[S|Prev],X).
Daniel@0: multi_match(S,Prev,X) :- match(S,X), \+member(S,Prev).
Daniel@0: multi_match((S,Ss),Prev,X) :- match(S,X), \+member(S,Prev), multi_match(Ss,[S|Prev],X).