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introduce cuts over indexed (:)/2 of dcgs:phrase_/3 (#786)

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Mark Thom
2021-02-03 16:03:12 -07:00
parent fcba140ffe
commit a8a82e45a0
1 changed files with 9 additions and 2 deletions
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11
src/lib/dcgs.pl
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@@ -31,11 +31,12 @@ phrase(GRBody, S0, S) :-
phrase_([], S, S).
phrase_(!, S, S).
phrase_(_:[], S, S).
phrase_(_:!, S, S).
phrase_(_:[], S, S) :- !.
phrase_(_:!, S, S) :- !.
phrase_((A, B), S0, S) :-
phrase(A, S0, S1), phrase(B, S1, S).
phrase_(M:(A, B), S0, S) :-
!,
phrase(M:A, S0, S1), phrase(M:B, S1, S).
phrase_((A -> B ; C), S0, S) :-
!,
@@ -52,26 +53,32 @@ phrase_(M:(A -> B ; C), S0, S) :-
phrase_((A ; B), S0, S) :-
( phrase(A, S0, S) ; phrase(B, S0, S) ).
phrase_(M:(A ; B), S0, S) :-
!,
( phrase(M:A, S0, S) ; phrase(M:B, S0, S) ).
phrase_((A | B), S0, S) :-
( phrase(A, S0, S) ; phrase(B, S0, S) ).
phrase_(M:(A | B), S0, S) :-
!,
( phrase(M:A, S0, S) ; phrase(M:B, S0, S) ).
phrase_({G}, S0, S) :-
( call(G), S0 = S ).
phrase_(M:{G}, S0, S) :-
!,
( call(M:G), S0 = S ).
phrase_(call(G), S0, S) :-
call(G, S0, S).
phrase_(M:call(G), S0, S) :-
!,
call(M:G, S0, S).
phrase_((A -> B), S0, S) :-
phrase((A -> B ; fail), S0, S).
phrase_(M:(A -> B), S0, S) :-
!,
phrase((M:A -> M:B ; fail), S0, S).
phrase_(phrase(NonTerminal), S0, S) :-
phrase(NonTerminal, S0, S).
phrase_(M:phrase(NonTerminal), S0, S) :-
!,
phrase(M:NonTerminal, S0, S).
phrase_([T|Ts], S0, S) :-
append([T|Ts], S, S0).