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yap-6.3/pl/control.yap
2012-12-07 08:08:32 +00:00

417 lines
10 KiB
Prolog

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: control.yap *
* Last rev: 20/08/09 *
* mods: *
* comments: control predicates available in yap *
* *
*************************************************************************/
once(G) :- '$execute'(G), !.
forall(Cond, Action) :- \+((Cond, \+(Action))).
ignore(Goal) :- (Goal->true;true).
if(X,Y,Z) :-
yap_hacks:env_choice_point(CP0),
(
CP is '$last_choice_pt',
'$call'(X,CP,if(X,Y,Z),M),
'$execute'(X),
'$clean_ifcp'(CP),
'$call'(Y,CP,if(X,Y,Z),M)
;
'$call'(Z,CP,if(X,Y,Z),M)
).
call(X,A) :- '$execute'(X,A).
call(X,A1,A2) :- '$execute'(X,A1,A2).
call(X,A1,A2,A3) :- '$execute'(X,A1,A2,A3).
call(X,A1,A2,A3,A4) :- '$execute'(X,A1,A2,A3,A4).
call(X,A1,A2,A3,A4,A5) :- '$execute'(X,A1,A2,A3,A4,A5).
call(X,A1,A2,A3,A4,A5,A6) :- '$execute'(X,A1,A2,A3,A4,A5,A6).
call(X,A1,A2,A3,A4,A5,A6,A7) :- '$execute'(X,A1,A2,A3,A4,A5,A6,A7).
call(X,A1,A2,A3,A4,A5,A6,A7,A8) :- '$execute'(X,A1,A2,A3,A4,A5,A6,A7,A8).
call(X,A1,A2,A3,A4,A5,A6,A7,A8,A9) :- '$execute'(X,A1,A2,A3,A4,A5,A6,A7,A8,A9).
call(X,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10) :- '$execute'(X,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10).
call(X,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10,A11) :- '$execute'(X,A1,A2,A3,A4,A5,A6,A7,A8,A9,A10,A11).
call_cleanup(Goal, Cleanup) :-
setup_call_catcher_cleanup(true, Goal, _Catcher, Cleanup).
call_cleanup(Goal, Catcher, Cleanup) :-
setup_call_catcher_cleanup(true, Goal, Catcher, Cleanup).
setup_call_cleanup(Setup, Goal, Cleanup) :-
setup_call_catcher_cleanup(Setup, Goal, _Catcher, Cleanup).
setup_call_catcher_cleanup(Setup, Goal, Catcher, Cleanup) :-
yap_hacks:disable_interrupts,
'$check_goal_for_setup_call_cleanup'(Setup, setup_call_cleanup(Setup, Goal, Cleanup)),
catch('$do_setup'(Setup),Exception,'$handle_broken_setup'(Exception)),
'$check_goal_for_setup_call_cleanup'(Cleanup, setup_call_cleanup(Setup, Goal, Cleanup)),
'$safe_call_cleanup'(Goal,Cleanup,Catcher,Exception).
% make sure we don't lose interrupts if we get exceptions
% with setup.
'$handle_broken_setup'(Exception) :-
yap_hacks:enable_interrupts,
throw(Exception).
'$check_goal_for_setup_call_cleanup'(Goal, G) :-
strip_module(Goal, _, MG),
(
var(MG)
->
yap_hacks:enable_interrupts,
'$do_error'(instantiation_error,G)
;
true
).
% this is simple, do nothing
'$do_setup'(A:true) :- atom(A), !.
% this is tricky: please don't forget that interrupts are disabled at this point
% and that they will only be enabled after setting up Cleanup
'$do_setup'(Setup) :-
(
'$execute'(Setup),
% we don't need to care about enabling interrupts
!
;
% reenable interrupts if Setup failed
yap_hacks:enable_interrupts,
fail
).
'$cleanup_exception'(Exception, exception(Exception), Cleanup) :- !,
% whatever happens, let exception go through
catch('$clean_call'(_,Cleanup),_,true),
throw(Exception).
'$cleanup_exception'(Exception, _, _) :-
throw(Exception).
'$safe_call_cleanup'(Goal, Cleanup, Catcher, Exception) :-
yap_hacks:current_choice_point(MyCP1),
'$coroutining':freeze_goal(Catcher, '$clean_call'(Active, Cleanup)),
(
yap_hacks:trail_suspension_marker(Catcher),
yap_hacks:enable_interrupts,
yap_hacks:current_choice_point(CP0),
'$execute'(Goal),
% ensure environment for delayed variables in Goal
'$true',
yap_hacks:current_choice_point(CPF),
(
CP0 =:= CPF
->
Catcher = exit,
!
;
true
)
;
Catcher = fail,
fail
).
'$holds_true'.
% The first argument is used by JumpEnv to verify if a throw
% is going to be handled by the cleanup catcher. If it is so,
% clean_call will not be called from JumpToEnv.
'$clean_call'(_, Cleanup) :-
'$execute'(Cleanup), !.
'$clean_call'(_, _).
'$cc_check_throw' :-
'$nb_getval'('$catch', Ball, fail),
throw(Ball).
%%% The unknown predicate,
% informs about what the user wants to be done when
% there are no clauses for a certain predicate */
unknown(V0,V) :-
'$current_module'(M),
'$unknown'(V0,V,M).
% query mode
'$unknown'(V0,V,_) :- var(V), !,
'$ask_unknown_flag'(V),
V = V0.
% handle modules.
'$unknown'(V0,Mod:Handler,_) :-
'$unknown'(V0,Handler,Mod).
% check if we have one we like.
'$unknown'(_,New,Mod) :-
'$valid_unknown_handler'(New,Mod), fail.
% clean up previous unknown predicate handlers
'$unknown'(Old,New,Mod) :-
recorded('$unknown','$unknown'(_,MyOld),Ref), !,
erase(Ref),
'$cleanup_unknown_handler'(MyOld,Old),
'$new_unknown'(New, Mod).
% store the new one.
'$unknown'(fail,New,Mod) :-
'$new_unknown'(New, Mod).
'$valid_unknown_handler'(V,_) :-
var(V), !,
'$do_error'(instantiation_error,yap_flag(unknown,V)).
'$valid_unknown_handler'(fail,_) :- !.
'$valid_unknown_handler'(error,_) :- !.
'$valid_unknown_handler'(warning,_) :- !.
'$valid_unknown_handler'(S,M) :-
functor(S,_,1),
arg(1,S,A),
var(A),
\+ '$undefined'(S,M),
!.
'$valid_unknown_handler'(S,_) :-
'$do_error'(domain_error(flag_value,unknown+S),yap_flag(unknown,S)).
'$ask_unknown_flag'(Old) :-
recorded('$unknown','$unknown'(_,MyOld),_), !,
'$cleanup_unknown_handler'(MyOld,Old).
'$ask_unknown_flag'(fail).
'$cleanup_unknown_handler'('$unknown_error'(_),error) :- !.
'$cleanup_unknown_handler'('$unknown_warning'(_),warning) :- !.
'$cleanup_unknown_handler'(Handler, Handler).
'$new_unknown'(fail,_) :- !.
'$new_unknown'(error,_) :- !,
recorda('$unknown','$unknown'(P,'$unknown_error'(P)),_).
'$new_unknown'(warning,_) :- !,
recorda('$unknown','$unknown'(P,'$unknown_warning'(P)),_).
'$new_unknown'(X,M) :-
arg(1,X,A),
recorda('$unknown','$unknown'(A,M:X),_).
'$unknown_error'(Mod:Goal) :-
functor(Goal,Name,Arity),
'$program_continuation'(PMod,PName,PAr),
'$do_error'(existence_error(procedure,Name/Arity),context(Mod:Goal,PMod:PName/PAr)).
'$unknown_warning'(Mod:Goal) :-
functor(Goal,Name,Arity),
'$program_continuation'(PMod,PName,PAr),
print_message(error,error(existence_error(procedure,Name/Arity), context(Mod:Goal,PMod:PName/PAr))),
fail.
%%% Some "dirty" predicates
% Only efective if yap compiled with -DDEBUG
% this predicate shows the code produced by the compiler
'$show_code' :- '$debug'(0'f). %' just make emacs happy
grow_heap(X) :- '$grow_heap'(X).
grow_stack(X) :- '$grow_stack'(X).
%
% gc() expects to be called from "call". Make sure it has an
% environment to return to.
%
%garbage_collect :- save(dump), '$gc', save(dump2).
garbage_collect :-
'$gc'.
gc :-
yap_flag(gc,on).
nogc :-
yap_flag(gc,off).
garbage_collect_atoms :-
'$atom_gc'.
'$force_environment_for_gc'.
'$good_list_of_character_codes'(V) :- var(V), !.
'$good_list_of_character_codes'([]).
'$good_list_of_character_codes'([X|L]) :-
'$good_character_code'(X),
'$good_list_of_character_codes'(L).
'$good_character_code'(X) :- var(X), !.
'$good_character_code'(X) :- integer(X), X > -2, X < 256.
(initialization) :-
'$initialisation_goals'.
prolog_initialization(G) :- var(G), !,
'$do_error'(instantiation_error,initialization(G)).
prolog_initialization(T) :- callable(T), !,
'$assert_init'(T).
prolog_initialization(T) :-
'$do_error'(type_error(callable,T),initialization(T)).
'$assert_init'(T) :- recordz('$startup_goal',T,_), fail.
'$assert_init'(_).
version :- '$version'.
version(V) :- var(V), !,
'$do_error'(instantiation_error,version(V)).
version(T) :- atom(T), !, '$assert_version'(T).
version(T) :-
'$do_error'(type_error(atom,T),version(T)).
'$assert_version'(T) :- recordz('$version',T,_), fail.
'$assert_version'(_).
'$set_toplevel_hook'(_) :-
recorded('$toplevel_hooks',_,R),
erase(R),
fail.
'$set_toplevel_hook'(H) :-
recorda('$toplevel_hooks',H,_),
fail.
'$set_toplevel_hook'(_).
'$oncenotrace'(G) :-
'$disable_creep', !,
(
'$execute'(G)
->
'$creep'
;
'$creep',
fail
).
'$oncenotrace'(G) :-
'$execute'(G), !.
'$once0'(G, M) :-
'$pred_exists'(G, M),
(
'$disable_creep'
->
(
'$execute_nonstop'(G, M)
->
'$creep'
;
'$creep',
fail
)
;
'$execute_nonstop'(G,M)
).
nb_getval(GlobalVariable, Val) :-
'$nb_getval'(GlobalVariable, Val, Error),
(var(Error)
->
true
;
'$getval_exception'(GlobalVariable, Val, nb_getval(GlobalVariable, Val)) ->
nb_getval(GlobalVariable, Val)
;
'$do_error'(existence_error(variable, GlobalVariable),nb_getval(GlobalVariable, Val))
).
b_getval(GlobalVariable, Val) :-
'$nb_getval'(GlobalVariable, Val, Error),
(var(Error)
->
true
;
'$getval_exception'(GlobalVariable, Val, b_getval(GlobalVariable, Val)) ->
true
;
'$do_error'(existence_error(variable, GlobalVariable),b_getval(GlobalVariable, Val))
).
/* This is the break predicate,
it saves the importante data about current streams and
debugger state */
break :-
nb_getval('$system_mode',SystemMode),
nb_getval('$trace',Trace),
nb_setval('$trace',off),
nb_getval('$debug_jump',Jump),
nb_getval('$debug_run',Run),
'$debug_on'(Debug),
'$debug_on'(false),
nb_getval('$break',BL), NBL is BL+1,
nb_getval('$spy_gn',SPY_GN),
b_getval('$spy_glist',GList),
b_setval('$spy_glist',[]),
nb_setval('$break',NBL),
current_output(OutStream), current_input(InpStream),
format(user_error, '% Break (level ~w)~n', [NBL]),
'$do_live',
!,
set_value('$live','$true'),
b_setval('$spy_glist',GList),
nb_setval('$spy_gn',SPY_GN),
set_input(InpStream),
set_output(OutStream),
'$debug_on'(Debug),
nb_setval('$debug_jump',Jump),
nb_setval('$debug_run',Run),
nb_setval('$trace',Trace),
nb_setval('$break',BL),
nb_setval('$system_mode',SystemMode).
at_halt(G) :-
recorda('$halt', G, _),
fail.
at_halt(_).
halt :-
print_message(informational, halt),
fail.
halt :-
'$halt'(0).
halt(_) :-
recorded('$halt', G, _),
call(G),
fail.
halt(X) :-
'$sync_mmapped_arrays',
set_value('$live','$false'),
'$halt'(X).
prolog_current_frame(Env) :-
Env is '$env'.
'$run_atom_goal'(GA) :-
'$current_module'(Module),
atom_to_term(GA, G, _),
'$system_catch'('$query'(once(G), []),Module,Error,user:'$Error'(Error)).
'$add_dot_to_atom_goal'([],[0'.]) :- !. %'
'$add_dot_to_atom_goal'([0'.],[0'.]) :- !.
'$add_dot_to_atom_goal'([C|Gs0],[C|Gs]) :-
'$add_dot_to_atom_goal'(Gs0,Gs).