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yap-6.3/pl/preddyns.yap
Vitor Santos Costa 54c6b8c041 documentation
2018-06-05 20:51:49 +01:00

352 lines
9.1 KiB
Prolog

% The next predicates are applicable only
% to dynamic code
/** @file preddyns.yap */
/**
* @addtogroup Database
* @{
*
* @brief main operations on dynamic predicates.
*/
/** @pred asserta(+ _C_) is iso
Adds clause _C_ to the beginning of the program. If the predicate is
undefined, it is declared dynamic (see dynamic/1).
*/
asserta(Clause) :-
'$assert'(Clause, asserta, _).
/** @pred assertz(+ _C_) is iso
Adds clause _C_ to the end of the program. If the predicate is
undefined, it is declared dynamic (see dynamic/1).
Most Prolog systems only allow asserting clauses for dynamic
predicates. This is also as specified in the ISO standard. YAP also allows
asserting clauses for static predicates, under the restriction that the static predicate may not be live in the stacks.
*/
assertz(Clause) :-
'$assert'(Clause, assertz, _).
/** @pred assert(+ _C_)
Same as assertz/1. Adds clause _C_ to the program. If the predicate is undefined,
declare it as dynamic. New code should use assertz/1 for better portability.
Most Prolog systems only allow asserting clauses for dynamic
predicates. This is also as specified in the ISO standard. YAP allows
asserting clauses for static predicates, as long as the predicate is not
in use and the language flag is <tt>cprolog</tt>. Note that this feature is
deprecated, if you want to assert clauses for static procedures you
should use assert_static/1.
*/
assert(Clause) :-
'$assert'(Clause, assertz, _).
'$assert'(Clause, Where, R) :-
'$yap_strip_clause'(Clause, _, _Clause0),
'$expand_clause'(Clause,C0,C),
'$$compile'(C, Where, C0, R).
/** @pred asserta(+ _C_,- _R_)
The same as `asserta(C)` but unifying _R_ with
the database reference that identifies the new clause, in a
one-to-one way. Note that `asserta/2` only works for dynamic
predicates. If the predicate is undefined, it will automatically be
declared dynamic.
*/
asserta(Clause, Ref) :-
'$assert'(Clause, asserta, Ref).
/** @pred assertz(+ _C_,- _R_)
The same as `assertz(C)` but unifying _R_ with
the database reference that identifies the new clause, in a
one-to-one way. Note that `asserta/2` only works for dynamic
predicates. If the predicate is undefined, it will automatically be
declared dynamic.
*/
assertz(Clause, Ref) :-
'$assert'(Clause, assertz, Ref).
/** @pred assert(+ _C_,- _R_)
The same as `assert(C)` ( (see Modifying the Database)) but
unifies _R_ with the database reference that identifies the new
clause, in a one-to-one way. Note that `asserta/2` only works for dynamic
predicates. If the predicate is undefined, it will automatically be
declared dynamic.
*/
assert(Clause, Ref) :-
'$assert'(Clause, assertz, Ref).
'$assertz_dynamic'(X, C, C0, Mod) :-
(X/\4)=:=0,
!,
'$head_and_body'(C,H,B),
'$assertat_d'(assertz,H,B,C0,Mod,_).
'$assertz_dynamic'(X,C,C0,Mod) :-
'$head_and_body'(C,H,B),
functor(H,N,A),
('$check_if_reconsulted'(N,A) ->
true
;
(X/\8)=:=0 ->
'$inform_as_reconsulted'(N,A),
'$remove_all_d_clauses'(H,Mod)
;
true
),
'$assertat_d'(assertz,H,B,C0,Mod,_).
'$remove_all_d_clauses'(H,M) :-
'$is_multifile'(H, M), !,
functor(H, Na, A),
'$erase_all_mf_dynamic'(Na,A,M).
'$remove_all_d_clauses'(H,M) :-
'$recordedp'(M:H,_,R), erase(R), fail.
'$remove_all_d_clauses'(_,_).
'$erase_all_mf_dynamic'(Na,A,M) :-
source_location( F , _),
recorded('$multifile_dynamic'(_,_,_), '$mf'(Na,A,M,F,R), R1),
erase(R1),
erase(R),
fail.
'$erase_all_mf_dynamic'(_,_,_).
'$assertat_d'(asserta,Head,Body,C0,Mod,R) :- !,
'$compile_dynamic'((Head:-Body), asserta, C0, Mod, CR),
( get_value('$abol',true)
->
'$predicate_flags'(Head,Mod,Fl,Fl),
( Fl /\ 0x20000000 =\= 0 -> '$check_multifile_pred'(Head,Mod,Fl) ; true )
;
true
),
'$head_and_body'(C0, H0, B0),
'$recordap'(Mod:Head,(H0 :- B0),R,CR),
( '$is_multifile'(Head, Mod) ->
source_location(F, _),
functor(H0, Na, Ar),
recorda('$multifile_dynamic'(_,_,_), '$mf'(Na,Ar,Mod,F,R), _)
;
true
).
'$assertat_d'(assertz,Head,Body,C0,Mod,R) :-
'$compile_dynamic'((Head:-Body), assertz, C0, Mod, CR),
( get_value('$abol',true)
->
'$predicate_flags'(Head,Mod,Fl,Fl),
( Fl /\ 0x20000000 =\= 0 -> '$check_multifile_pred'(Head,Mod,Fl) ; true )
;
true
),
'$head_and_body'(C0, H0, B0),
'$recordzp'(Mod:Head,(H0 :- B0),R,CR),
( '$is_multifile'(H0, Mod) ->
source_location(F, _),
functor(H0, Na, Ar),
recordz('$multifile_dynamic'(_,_,_), '$mf'(Na,Ar,Mod,F,R), _)
;
true
).
/** @pred retract(+ _C_) is iso
Erases the first clause in the program that matches _C_. This
predicate may also be used for the static predicates that have been
compiled when the source mode was `on`. For more information on
source/0 ( (see Setting the Compiler)).
*/
retract( C ) :-
strip_module( C, M, C0),
'$check_head_and_body'(M:C0,M1,H,B,retract(M:C)),
'$predicate_flags'(H, M1, F, F),
'$retract2'(F, H, M1, B,_).
'$retract2'(F, H, M, B, R) :-
F /\ 0x08000000 =:= 0x08000000, !,
% '$is_log_updatable'(H, M), !,
'$log_update_clause'(H,M,B,R),
( F /\ 0x20000000 =:= 0x20000000, recorded('$mf','$mf_clause'(_,_,_,_,R),MR), erase(MR), fail ; true),
erase(R).
'$retract2'(F, H, M, B, R) :-
% '$is_dynamic'(H,M), !,
F /\ 0x00002000 =:= 0x00002000, !,
'$recordedp'(M:H,(H:-B),R),
( F /\ 0x20000000 =:= 0x20000000, recorded('$mf','$mf_clause'(_,_,_,_,MRef),MR), erase(MR), erase(MRef), fail ; true),
erase(R).
'$retract2'(_, H,M,_,_) :-
'$undefined'(H,M), !,
functor(H,Na,Ar),
'$dynamic'(Na/Ar,M),
fail.
'$retract2'(_, H,M,B,_) :-
functor(H,Na,Ar),
\+ '$dynamic'(Na/Ar,M),
'$do_error'(permission_error(modify,static_procedure,Na/Ar),retract(M:(H:-B))).
/** @pred retract(+ _C_,- _R_)
Erases from the program the clause _C_ whose
database reference is _R_. The predicate must be dynamic.
*/
retract(M:C,R) :- !,
'$yap_strip_module'( C, M, H0),
'$retract'(H0, M, R).
'$retract'(C, M0, R) :-
db_reference(R),
'$check_head_and_body'(M0:C,M,H,B,retract(C,R)),
dynamic(H,M),
!,
instance(R,(H:-B)),
erase(R).
'$retract'(C,M0,R) :-
'$check_head_and_body'(M0:C,M,H,B,retract(C,R)),
var(R), !,
'$retract2'(H, M, B, R).
'$retract'(C,M,_) :-
'$fetch_predicate_indicator_from_clause'(C, M, PI),
\+ '$dynamic'(PI),
'$do_error'(permission_error(modify,static_procedure,PI),retract(M:C)).
'$fetch_predicate_indicator_from_clause'((C :- _), M:Na/Ar) :-
!,
'$yap_strip_module'(C, M, C1),
functor(C1, Na, Ar).
'$fetch_predicate_indicator_from_clause'(C, M:Na/Ar) :-
'$yap_strip_module'(C, M, C1),
functor(C1, Na, Ar).
/** @pred retractall(+ _G_) is iso
Retract all the clauses whose head matches the goal _G_. Goal
_G_ must be a call to a dynamic predicate.
*/
retractall(M:V) :- !,
'$retractall'(V,M).
retractall(V) :-
'$current_module'(M),
'$retractall'(V,M).
'$retractall'(V,M) :- var(V), !,
'$do_error'(instantiation_error,retract(M:V)).
'$retractall'(M:V,_) :- !,
'$retractall'(V,M).
'$retractall'(T,M) :-
functor(T,Na,Ar),
(
'$is_log_updatable'(T, M) ->
( '$is_multifile'(T, M) ->
'$retractall_lu_mf'(T,M,Na,Ar)
;
'$retractall_lu'(T,M)
)
;
\+ callable(T) ->
'$do_error'(type_error(callable,T),retractall(T))
;
'$undefined'(T,M) ->
'$dynamic'(Na/Ar,M), !
;
'$is_dynamic'(T,M) ->
'$erase_all_clauses_for_dynamic'(T, M)
;
'$do_error'(permission_error(modify,static_procedure,Na/Ar),retractall(T))
).
'$retractall_lu'(T,M) :-
'$free_arguments'(T), !,
( '$purge_clauses'(T,M), fail ; true ).
'$retractall_lu'(T,M) :-
'$log_update_clause'(T,M,_,R),
erase(R),
fail.
'$retractall_lu'(_,_).
'$retractall_lu_mf'(T,M,Na,Ar) :-
'$log_update_clause'(T,M,_,R),
( recorded('$mf','$mf_clause'(_,Na,Ar,M,R),MR), erase(MR), fail ; true),
erase(R),
fail.
'$retractall_lu_mf'(_,_,_,_).
'$erase_all_clauses_for_dynamic'(T, M) :-
'$recordedp'(M:T,(T :- _),R), erase(R), fail.
'$erase_all_clauses_for_dynamic'(T,M) :-
'$recordedp'(M:T,_,_), fail.
'$erase_all_clauses_for_dynamic'(_,_).
/* support for abolish/1 */
'$abolishd'(T, M) :-
'$is_multifile'(T,M),
functor(T,Name,Arity),
recorded('$mf','$mf_clause'(_,Name,Arity,M,Ref),R),
erase(R),
erase(Ref),
fail.
'$abolishd'(T, M) :-
recorded('$import','$import'(_,M,_,T,_,_),R),
erase(R),
fail.
'$abolishd'(T, M) :-
'$purge_clauses'(T,M), fail.
'$abolishd'(T, M) :-
'$kill_dynamic'(T,M), fail.
'$abolishd'(_, _).
/** @pred dynamic_predicate(+ _P_,+ _Semantics_)
Declares predicate _P_ or list of predicates [ _P1_,..., _Pn_]
as a dynamic predicate following either `logical` or
`immediate` semantics.
*/
dynamic_predicate(P,Sem) :-
'$bad_if_is_semantics'(Sem, dynamic(P,Sem)).
dynamic_predicate(P,Sem) :-
'$log_upd'(OldSem),
( Sem = logical -> '$switch_log_upd'(1) ; '$switch_log_upd'(0) ),
'$current_module'(M),
'$dynamic'(P, M),
'$switch_log_upd'(OldSem).
'$bad_if_is_semantics'(Sem, Goal) :-
var(Sem), !,
'$do_error'(instantiation_error,Goal).
'$bad_if_is_semantics'(Sem, Goal) :-
Sem \= immediate, Sem \= logical, !,
'$do_error'(domain_error(semantics_indicator,Sem),Goal).
%% @}