47 lines
835 B
Plaintext
47 lines
835 B
Plaintext
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% This file has been included as an YAP library by Vitor Santos Costa, 2008
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% it is based on the arg library from Quintus Prolog
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:- module(arg,
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[
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genarg/3,
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arg0/3,
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genarg0/3,
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args/3,
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args0/3,
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% project/3
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path_arg/3
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]).
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arg0(0,T,A) :- !,
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functor(T,A,_).
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arg0(I,T,A) :-
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arg(I,T,A).
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genarg0(I,T,A) :-
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nonvar(I), !,
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arg0(I,T,A).
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genarg0(0,T,A) :-
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functor(T,A,_).
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genarg0(I,T,A) :-
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arg(I,T,A).
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args(_,[],[]).
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args(I,[T|List],[A|ArgList]) :-
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genarg(I, T, A),
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args(I, List, ArgList).
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args0(_,[],[]).
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args0(I,[T|List],[A|ArgList]) :-
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genarg(I, T, A),
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args0(I, List, ArgList).
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project(Terms, Index, Args) :-
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args0(Index, Terms, Args).
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% no error checking here!
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path_arg([], Term, Term).
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path_arg([Index|Indices], Term, SubTerm) :-
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genarg(Index, Term, Arg),
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path_arg(Indices, Arg, SubTerm).
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