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tag DCG constructs with module names for proper resolution

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This commit is contained in:
Mark Thom
2021-11-19 23:00:56 -07:00
parent addc817cca
commit 0e2db4a23e
5 changed files with 146 additions and 103 deletions
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150
src/lib/dcgs.pl
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@@ -1,16 +1,25 @@
:- module(dcgs,
[op(1105, xfy, '|'),
phrase/2,
phrase/3,
seq//1,
seqq//1,
... //0
]).
phrase/2,
phrase/3,
seq//1,
seqq//1,
... //0
]).
:- use_module(library(error)).
:- use_module(library(lists), [append/3]).
:- use_module(library(lists), [append/3, member/2]).
:- use_module(library(loader), [strip_module/3]).
load_context(GRBody, Module, GRBody0) :-
strip_module(GRBody, Module, GRBody0),
( nonvar(Module) ->
true
; prolog_load_context(module, Module) ->
true
; true
).
:- meta_predicate phrase(2, ?).
:- meta_predicate phrase(2, ?, ?).
@@ -18,77 +27,78 @@
phrase(GRBody, S0) :-
phrase(GRBody, S0, []).
phrase(GRBody, S0, S) :-
( var(GRBody) ->
throw(error(instantiation_error, phrase/3))
; strip_module(GRBody, Module, GRBody0),
; load_context(GRBody, Module, GRBody0),
dcg_constr(GRBody0) ->
( var(Module) ->
phrase_(GRBody0, S0, S)
; phrase_(Module:GRBody0, S0, S)
; phrase_(GRBody0, S0, S, Module)
)
; functor(GRBody, _, _) ->
call(GRBody, S0, S)
; throw(error(type_error(callable, GRBody), phrase/3))
).
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) :-
!,
( phrase(A, S0, S1) ->
phrase(B, S1, S)
; phrase(C, S0, S)
).
phrase_(M:(A -> B ; C), S0, S) :-
!,
phrase_([], S, S, _).
phrase_(!, S, S, _).
phrase_((A, B), S0, S, M) :-
phrase(M:A, S0, S1),
phrase(M:B, S1, S).
phrase_((A -> B ; C), S0, S, M) :-
( phrase(M:A, S0, S1) ->
phrase(M:B, S1, S)
; phrase(M: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) :-
!,
phrase_((A ; B), S0, S, M) :-
( phrase(M:A, S0, S)
; phrase(M:B, S0, S)
).
phrase_((A | B), S0, S, M) :-
( phrase(M:A, S0, S)
; phrase(M:B, S0, S)
).
phrase_({G}, S, S, M) :-
call(M:G).
phrase_(call(G), S0, S, M) :-
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).
phrase_(_:[T|Ts], S0, S) :-
phrase_((A -> B), S0, S, M) :-
( phrase(M:A, S0, S1) ->
phrase(M:B, S1, S)
; fail
).
phrase_(phrase(NonTerminal), S0, S, M) :-
phrase(NonTerminal, S0, S, M).
phrase_([T|Ts], S0, S, _) :-
append([T|Ts], S, S0).
phrase_([], S, S).
phrase_(!, S, S).
phrase_(M:G, S0, S) :-
phrase_(G, S0, S, M).
phrase_((A, B), S0, S) :-
phrase(A, S0, S1),
phrase(B, S1, S).
phrase_((A -> B ; C), S0, S) :-
( phrase(A, S0, S1) ->
phrase(B, S1, S)
; phrase(C, S0, S)
).
phrase_((A ; B), S0, S) :-
( phrase(A, S0, S) ; phrase(B, S0, S) ).
phrase_((A | B), S0, S) :-
( phrase(A, S0, S) ; phrase(B, S0, S) ).
phrase_({G}, S0, S) :-
( call(G), S0 = S ).
phrase_(call(G), S0, S) :-
call(G, S0, S).
phrase_((A -> B), S0, S) :-
phrase((A -> B ; fail), S0, S).
phrase_(phrase(NonTerminal), S0, S) :-
phrase(NonTerminal, S0, S).
phrase_([T|Ts], S0, S) :-
append([T|Ts], S, S0).
% The same version of the below two dcg_rule clauses, but with module scoping.
dcg_rule(( M:NonTerminal, Terminals --> GRBody ), ( M:Head :- Body )) :-
@@ -193,3 +203,25 @@ seqq([Es|Ess]) --> seq(Es), seqq(Ess).
% Describes an arbitrary number of elements
... --> [] | [_], ... .
user:goal_expansion(phrase(GRBody, S, S0), phrase(GRBody1, S, S0)) :-
strip_module(GRBody, M, GRBody0),
var(M),
prolog_load_context(module, M),
( nonvar(GRBody0) ->
GRBody0 \== [],
dcg_constr(GRBody0),
predicate_property(GRBody0, meta_predicate(_))
),
GRBody1 = M:GRBody0.
user:goal_expansion(phrase(GRBody, S), phrase(GRBody1, S, [])) :-
strip_module(GRBody, M, GRBody0),
var(M),
prolog_load_context(module, M),
( nonvar(GRBody0) ->
GRBody0 \== [],
dcg_constr(GRBody0),
predicate_property(GRBody0, meta_predicate(_))
),
GRBody1 = M:GRBody0.