348 lines
9.0 KiB
Prolog
348 lines
9.0 KiB
Prolog
% The next predicates are applicable only
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% to dynamic code
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/** @file preddyns.yap */
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/**
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* @ingroup Database
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* @{
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Next follow the main operations on dynamic predicates.
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*/
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/** @pred asserta(+ _C_) is iso
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Adds clause _C_ to the beginning of the program. If the predicate is
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undefined, it is declared dynamic (see dynamic/1).
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*/
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asserta(Clause) :-
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'$assert'(Clause, asserta, _).
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/** @pred assertz(+ _C_) is iso
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Adds clause _C_ to the end of the program. If the predicate is
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undefined, it is declared dynamic (see dynamic/1).
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Most Prolog systems only allow asserting clauses for dynamic
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predicates. This is also as specified in the ISO standard. YAP also allows
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asserting clauses for static predicates, under the restriction that the static predicate may not be live in the stacks.
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*/
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assertz(Clause) :-
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'$assert'(Clause, assertz, _).
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/** @pred assert(+ _C_)
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Same as assertz/1. Adds clause _C_ to the program. If the predicate is undefined,
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declare it as dynamic. New code should use assertz/1 for better portability.
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Most Prolog systems only allow asserting clauses for dynamic
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predicates. This is also as specified in the ISO standard. YAP allows
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asserting clauses for static predicates, as long as the predicate is not
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in use and the language flag is <tt>cprolog</tt>. Note that this feature is
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deprecated, if you want to assert clauses for static procedures you
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should use assert_static/1.
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*/
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assert(Clause) :-
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'$assert'(Clause, assertz, _).
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'$assert'(Clause, Where, R) :-
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'$expand_clause'(Clause,C0,C),
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'$$compile'(C, Where, C0, R).
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/** @pred asserta(+ _C_,- _R_)
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The same as `asserta(C)` but unifying _R_ with
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the database reference that identifies the new clause, in a
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one-to-one way. Note that `asserta/2` only works for dynamic
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predicates. If the predicate is undefined, it will automatically be
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declared dynamic.
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*/
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asserta(Clause, Ref) :-
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'$assert'(Clause, first, Ref).
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/** @pred assertz(+ _C_,- _R_)
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The same as `assertz(C)` but unifying _R_ with
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the database reference that identifies the new clause, in a
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one-to-one way. Note that `asserta/2` only works for dynamic
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predicates. If the predicate is undefined, it will automatically be
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declared dynamic.
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*/
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assertz(Clause, Ref) :-
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'$assert'(Clause, last, Ref).
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/** @pred assert(+ _C_,- _R_)
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The same as `assert(C)` ( (see Modifying the Database)) but
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unifies _R_ with the database reference that identifies the new
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clause, in a one-to-one way. Note that `asserta/2` only works for dynamic
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predicates. If the predicate is undefined, it will automatically be
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declared dynamic.
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*/
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assert(Clause, Ref) :-
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'$assert'(Clause, last, Ref).
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'$assertz_dynamic'(X, C, C0, Mod) :-
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(X/\4)=:=0,
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!,
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'$head_and_body'(C,H,B),
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'$assertat_d'(last,H,B,C0,Mod,_).
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'$assertz_dynamic'(X,C,C0,Mod) :-
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'$head_and_body'(C,H,B),
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functor(H,N,A),
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('$check_if_reconsulted'(N,A) ->
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true
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;
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(X/\8)=:=0 ->
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'$inform_as_reconsulted'(N,A),
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'$remove_all_d_clauses'(H,Mod)
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;
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true
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),
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'$assertat_d'(last,H,B,C0,Mod,_).
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'$remove_all_d_clauses'(H,M) :-
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'$is_multifile'(H, M), !,
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functor(H, Na, A),
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'$erase_all_mf_dynamic'(Na,A,M).
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'$remove_all_d_clauses'(H,M) :-
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'$recordedp'(M:H,_,R), erase(R), fail.
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'$remove_all_d_clauses'(_,_).
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'$erase_all_mf_dynamic'(Na,A,M) :-
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source_location( F , _),
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recorded('$multifile_dynamic'(_,_,_), '$mf'(Na,A,M,F,R), R1),
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erase(R1),
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erase(R),
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fail.
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'$erase_all_mf_dynamic'(_,_,_).
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'$assertat_d'(first,Head,Body,C0,Mod,R) :- !,
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'$compile_dynamic'((Head:-Body), first, C0, Mod, CR),
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( get_value('$abol',true)
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->
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'$predicate_flags'(Head,Mod,Fl,Fl),
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( Fl /\ 0x20000000 =\= 0 -> '$check_multifile_pred'(Head,Mod,Fl) ; true )
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;
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true
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),
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'$head_and_body'(C0, H0, B0),
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'$recordap'(Mod:Head,(H0 :- B0),R,CR),
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( '$is_multifile'(Head, Mod) ->
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source_location(F, _),
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functor(H0, Na, Ar),
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recorda('$multifile_dynamic'(_,_,_), '$mf'(Na,Ar,Mod,F,R), _)
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;
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true
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).
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'$assertat_d'(last,Head,Body,C0,Mod,R) :-
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'$compile_dynamic'((Head:-Body), last, C0, Mod, CR),
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( get_value('$abol',true)
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->
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'$predicate_flags'(Head,Mod,Fl,Fl),
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( Fl /\ 0x20000000 =\= 0 -> '$check_multifile_pred'(Head,Mod,Fl) ; true )
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;
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true
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),
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'$head_and_body'(C0, H0, B0),
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'$recordzp'(Mod:Head,(H0 :- B0),R,CR),
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( '$is_multifile'(H0, Mod) ->
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source_location(F, _),
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functor(H0, Na, Ar),
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recordz('$multifile_dynamic'(_,_,_), '$mf'(Na,Ar,Mod,F,R), _)
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;
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true
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).
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/** @pred retract(+ _C_) is iso
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Erases the first clause in the program that matches _C_. This
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predicate may also be used for the static predicates that have been
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compiled when the source mode was `on`. For more information on
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source/0 ( (see Setting the Compiler)).
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*/
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retract( C ) :-
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strip_module( C, M, C0),
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'$check_head_and_body'(C0,M,H,B,retract(M:C)),
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'$predicate_flags'(H, M, F, F),
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'$retract2'(F, H,M,B,_).
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'$retract2'(F, H, M, B, R) :-
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F /\ 0x08000000 =:= 0x08000000, !,
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% '$is_log_updatable'(H, M), !,
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'$log_update_clause'(H,M,B,R),
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( F /\ 0x20000000 =:= 0x20000000, recorded('$mf','$mf_clause'(_,_,_,_,R),MR), erase(MR), fail ; true),
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erase(R).
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'$retract2'(F, H, M, B, R) :-
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% '$is_dynamic'(H,M), !,
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F /\ 0x00002000 =:= 0x00002000, !,
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'$recordedp'(M:H,(H:-B),R),
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( F /\ 0x20000000 =:= 0x20000000, recorded('$mf','$mf_clause'(_,_,_,_,MRef),MR), erase(MR), erase(MRef), fail ; true),
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erase(R).
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'$retract2'(_, H,M,_,_) :-
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'$undefined'(H,M), !,
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functor(H,Na,Ar),
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'$dynamic'(Na/Ar,M),
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fail.
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'$retract2'(_, H,M,B,_) :-
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functor(H,Na,Ar),
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\+ '$dynamic'(Na/Ar,M),
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'$do_error'(permission_error(modify,static_procedure,Na/Ar),retract(M:(H:-B))).
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/** @pred retract(+ _C_,- _R_)
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Erases from the program the clause _C_ whose
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database reference is _R_. The predicate must be dynamic.
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*/
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retract(M:C,R) :- !,
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'$yap_strip_module'( C, M, H0),
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'$retract'(H0, M, R).
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'$retract'(C, M0, R) :-
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db_reference(R),
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!,
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'$is_dynamic'(H,M),
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'$check_head_and_body'(M0:C,M,H,B,retract(C,R)),
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instance(R,(H:-B)),
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erase(R).
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'$retract'(C,M0,R) :-
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'$check_head_and_body'(M0:C,M,H,B,retract(C,R)),
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var(R), !,
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'$retract2'(H, M, B, R).
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'$retract'(C,M,_) :-
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'$fetch_predicate_indicator_from_clause'(C, M, PI),
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\+ '$dynamic'(PI),
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'$do_error'(permission_error(modify,static_procedure,PI),retract(M:C)).
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'$fetch_predicate_indicator_from_clause'((C :- _), M:Na/Ar) :-
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!,
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functor(C, Na, Ar).
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'$fetch_predicate_indicator_from_clause'(C, M:Na/Ar) :-
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functor(C, Na, Ar).
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/** @pred retractall(+ _G_) is iso
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Retract all the clauses whose head matches the goal _G_. Goal
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_G_ must be a call to a dynamic predicate.
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*/
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retractall(M:V) :- !,
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'$retractall'(V,M).
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retractall(V) :-
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'$current_module'(M),
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'$retractall'(V,M).
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'$retractall'(V,M) :- var(V), !,
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'$do_error'(instantiation_error,retract(M:V)).
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'$retractall'(M:V,_) :- !,
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'$retractall'(V,M).
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'$retractall'(T,M) :-
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(
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'$is_log_updatable'(T, M) ->
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( '$is_multifile'(T, M) ->
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'$retractall_lu_mf'(T,M)
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;
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'$retractall_lu'(T,M)
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)
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;
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\+ callable(T) ->
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'$do_error'(type_error(callable,T),retractall(T))
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;
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'$undefined'(T,M) ->
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functor(T,Na,Ar),
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'$dynamic'(Na/Ar,M), !
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;
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'$is_dynamic'(T,M) ->
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'$erase_all_clauses_for_dynamic'(T, M)
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;
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functor(T,Na,Ar),
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'$do_error'(permission_error(modify,static_procedure,Na/Ar),retractall(T))
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).
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'$retractall_lu'(T,M) :-
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'$free_arguments'(T), !,
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( '$purge_clauses'(T,M), fail ; true ).
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'$retractall_lu'(T,M) :-
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'$log_update_clause'(T,M,_,R),
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erase(R),
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fail.
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'$retractall_lu'(_,_).
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'$retractall_lu_mf'(T,M) :-
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'$log_update_clause'(T,M,_,R),
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( recorded('$mf','$mf_clause'(_,_,_,_,R),MR), erase(MR), fail ; true),
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erase(R),
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fail.
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'$retractall_lu_mf'(_,_).
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'$erase_all_clauses_for_dynamic'(T, M) :-
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'$recordedp'(M:T,(T :- _),R), erase(R), fail.
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'$erase_all_clauses_for_dynamic'(T,M) :-
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'$recordedp'(M:T,_,_), fail.
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'$erase_all_clauses_for_dynamic'(_,_).
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/* support for abolish/1 */
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'$abolishd'(T, M) :-
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'$is_multifile'(T,M),
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functor(T,Name,Arity),
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recorded('$mf','$mf_clause'(_,Name,Arity,M,Ref),R),
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erase(R),
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erase(Ref),
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fail.
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'$abolishd'(T, M) :-
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recorded('$import','$import'(_,M,_,T,_,_),R),
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erase(R),
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fail.
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'$abolishd'(T, M) :-
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'$purge_clauses'(T,M), fail.
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'$abolishd'(T, M) :-
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'$kill_dynamic'(T,M), fail.
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'$abolishd'(_, _).
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/** @pred dynamic_predicate(+ _P_,+ _Semantics_)
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Declares predicate _P_ or list of predicates [ _P1_,..., _Pn_]
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as a dynamic predicate following either `logical` or
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`immediate` semantics.
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*/
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dynamic_predicate(P,Sem) :-
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'$bad_if_is_semantics'(Sem, dynamic(P,Sem)).
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dynamic_predicate(P,Sem) :-
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'$log_upd'(OldSem),
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( Sem = logical -> '$switch_log_upd'(1) ; '$switch_log_upd'(0) ),
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'$current_module'(M),
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'$dynamic'(P, M),
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'$switch_log_upd'(OldSem).
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'$bad_if_is_semantics'(Sem, Goal) :-
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var(Sem), !,
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'$do_error'(instantiation_error,Goal).
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'$bad_if_is_semantics'(Sem, Goal) :-
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Sem \= immediate, Sem \= logical, !,
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'$do_error'(domain_error(semantics_indicator,Sem),Goal).
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