/*************************************************************************
*									 *
*	 YAP Prolog 							 *
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		consult.yap						 *
* Last rev:	8/2/88							 *
* mods:									 *
* comments:	Consulting Files in YAP					 *
*									 *
*************************************************************************/

%
% SWI options
% autoload(true,false)
% derived_from(File) -> make
% encoding(Enconding)
% expand({true,false)
% if(changed,true,not_loaded)
% imports(all,List)
% qcompile(true,false)
% silent(true,false)  => implemented
% stream(Stream)  => implemented
% consult(consult,reconsult) 
%
load_files(Files,Opts) :-
	'$load_files'(Files,Opts,load_files(Files,Opts)).

'$load_files'(Files,Opts,Call) :-		    
	'$process_lf_opts'(Opts,Silent,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult,Files,Call),
        '$current_module'(M0),
	'$lf'(Files,M0,Call,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult),
	'$close_lf'(Silent).

'$process_lf_opts'(V,_,_,_,_,_,_,_,_,_,_,Call) :-
	var(V), !,
	'$do_error'(instantiation_error,Call).
'$process_lf_opts'([],_,_,_,_,_,_,_,_,_,_,_).
'$process_lf_opts'([Opt|Opts],Silent,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult,Files,Call) :-
	'$process_lf_opt'(Opt,Silent,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult,Files,Call), !, 
	'$process_lf_opts'(Opts,Silent,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult,Files,Call).
'$process_lf_opts'([Opt|Opts],_,_,_,_,_,_,_,_,_,_,Call) :-
	'$do_error'(domain_error(unimplemented_option,Opt),Call).

'$process_lf_opt'(autoload(true),_,InfLevel,_,_,_,_,_,_,_,_,_) :-
	get_value('$verbose_auto_load',VAL),
	(VAL = true ->
	    InfLevel = informational
	;
	    InfLevel = silent
	).
'$process_lf_opt'(autoload(false),_,_,_,_,_,_,_,_,_,_,_).
'$process_lf_opt'(derived_from(File),_,_,_,_,_,_,_,_,_,Files,Call) :-
	( atom(File) -> true ;  '$do_error'(type_error(atom,File),Call) ),
	( atom(Files) -> true ;  '$do_error'(type_error(atom,Files),Call) ),
	/* call make */
	'$do_error'(domain_error(unimplemented_option,derived_from),Call).
'$process_lf_opt'(encoding(Encoding),_,_,_,_,_,_,_,_,_,_,Call) :-
	'$do_error'(domain_error(unimplemented_option,encoding),Call).
'$process_lf_opt'(expand(true),_,_,true,_,_,_,_,_,_,_,Call) :-
	'$do_error'(domain_error(unimplemented_option,expand),Call).
'$process_lf_opt'(expand(false),_,_,false,_,_,_,_,_,_,_,_).
'$process_lf_opt'(if(changed),_,_,_,changed,_,_,_,_,_,_,_).
'$process_lf_opt'(if(true),_,_,_,true,_,_,_,_,_,_,_).
'$process_lf_opt'(if(not_loaded),_,_,_,not_loaded,_,_,_,_,_,_,_).
'$process_lf_opt'(imports(all),_,_,_,_,_,_,_,_,_,_).
'$process_lf_opt'(imports(Imports),_,_,_,_,_,Imports,_,_,_,_,_).
'$process_lf_opt'(qcompile(true),_,_,_,_,true,_,_,_,_,_,Call) :-
	'$do_error'(domain_error(unimplemented_option,qcompile),Call).
'$process_lf_opt'(qcompile(false),_,_,_,_,false,_,_,_,_,_).
'$process_lf_opt'(silent(true),Silent,silent,_,_,_,_,_,_,_,_,_) :-
	( get_value('$lf_verbose',Silent) -> true ;  Silent = informational),
	set_value('$lf_verbose',silent).
'$process_lf_opt'(silent(false),_,_,_,_,_,_,_,_,_,_,_).
'$process_lf_opt'(consult(reconsult),_,_,_,_,_,_,_,_,reconsult,_,_).
'$process_lf_opt'(consult(consult),_,_,_,_,_,_,_,_,consult,_,_).
'$process_lf_opt'(stream(Stream),_,_,_,_,_,_,_,Stream,_,_,_,Call) :-
	( '$stream'(Stream) -> true ;  '$do_error'(domain_error(stream,Stream),Call) ),
	( atom(Files) -> true ;  '$do_error'(type_error(atom,Files),Call) ).

'$lf'(V,_,Call,_,_,_,_,_,_,_) :- var(V), !,
	'$do_error'(instantiation_error,Call).
'$lf'([],_,_,_,_,_,_,_,_,_,_) :- !.
'$lf'(M:X, _, Call,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult) :- !,
	(
	  atom(M)
	->
	  '$lf'(X, M, Call,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult)
	  ;
	  '$do_error'(type_error(atom,M),Call)
	).
'$lf'([F|Fs], Mod,Call,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult) :- !,
	'$lf'(F, Mod,Call,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult),
	'$lf'(Fs, Mod,Call,InfLevel,Expand,Changed,CompilationMode,Imports,Stream,Encoding,Reconsult).
'$lf'(X, Mod, Call,InfLevel,_,Changed,CompilationMode,Imports,Stream,_,Reconsult) :-
        nonvar(Stream), !,
	'$do_lf'(X, Mod, Stream, InfLevel,CompilationMode,Imports,Reconsult).
'$lf'(user, Mod, Call,InfLevel,_,Changed,CompilationMode,Imports,_,_,Reconsult) :- !,
	'$do_lf'(user_input, Mod, user_input, InfLevel, CompilationMode,Imports,Reconsult).
'$lf'(user_input, Mod, Call,InfLevel,_,Changed,CompilationMode,Imports,_,_) :- !,
	'$do_lf'(user_input, Mod, user_input, InfLevel, CompilationMode,Imports).
'$lf'(X, Mod, Call, InfLevel,_,Changed,CompilationMode,Imports,_,_,Reconsult) :-
	'$find_in_path'(X, Y, Call),
	'$open'(Y, '$csult', Stream, 0), !,
	'$start_lf'(X, Mod, Stream, InfLevel, CompilationMode, Imports, Changed,Reconsult),
	'$close'(Stream).
'$lf'(X, _, Call, _, _, _, _, _, _, _,_) :-
	'$do_error'(permission_error(input,stream,X),Call).


'$start_lf'(_, Mod, Stream,_ ,_, Imports, not_loaded, _) :-
	'$file_loaded'(Stream, Mod, Imports), !.
'$start_lf'(_, Mod, Stream, _, _, Imports, changed, _) :-
	'$file_unchanged'(Stream, Mod, Imports), !.
'$start_lf'(X, Mod, Stream, InfLevel, CompilationMode, Imports, _, Reconsult) :-
	'$do_lf'(X, Mod, Stream, InfLevel, CompilationMode, Imports, Reconsult).

'$close_lf'(Silent) :- 
	nonvar(Silent),
	set_value('$lf_verbose',Silent).
	
ensure_looaded(Fs) :-
	'$load_files'(Fs, [if(changed)],ensure_loaded(Fs)).

compile(Fs) :-
	'$load_files'(Fs, [], compile(Fs)).

consult(Fs) :-
	'$has_yap_or',
	'$do_error'(context_error(consult(Fs),clause),query).
consult(V) :-
	var(V), !,
	'$do_error'(instantiation_error,consult(V)).
consult(M0:Fs) :- !,
	'$consult'(Fs, M0).
consult(Fs) :-
	'$current_module'(M0),
	'$consult'(Fs, M0).

'$consult'(Fs,Module) :-
	'$access_yap_flags'(8, 2), % SICStus Prolog compatibility
	!,
	'$load_files'(Module:Fs,[],Fs).
'$consult'(Fs, Module) :- var(V), !,
	'$load_files'(Module:Fs,[reconsult(consult)],Fs).

reconsult(Fs) :-
	'$load_files'(Fs, [], reconsult(Fs)).

use_module(F) :-
	'$load_files'(F, [if(not_loaded)],use_module(F)).

use_module(F,Is) :-
	'$load_files'(F, [if(not_loaded),imports(Is)],use_module(F,Is)).

use_module(M,F,Is) :-
	'$load_files'(F, [if(not_loaded),imports(Is)],use_module(M,F,Is)).

'$do_lf'(F, ContextModule, Stream, InfLevel, _, Imports, Reconsult) :-
	'$record_loaded'(Stream, M),
	'$current_module'(OldModule,ContextModule),
	'$getcwd'(OldD),
	get_value('$consulting_file',OldF),
	'$set_consulting_file'(Stream),
	H0 is heapused, '$cputime'(T0,_),
	current_stream(File,_,Stream),
	get_value('$consulting',Old),
	set_value('$consulting',false),
	'$consult_infolevel'(InfLevel),
	recorda('$initialisation','$',_),
	( Reconsult = reconsult ->
	    '$start_reconsulting'(F)
	    '$start_consult'(Reconsult,File,LC),
	    '$remove_multifile_clauses'(File),
	    StartMsg = reconsulting,
	    EndMsg = reconsulted
	    ;
	    '$start_consult'(Reconsult,File,LC),
	    StartMsg = consulting,
	    EndMsg = consulted
	),
	'$print_message'(InfLevel, loading(StartMsg, File)),
	( recorded('$trace', on, TraceR) -> erase(TraceR) ; true),
	'$loop'(Stream,reconsult),
	'$end_consult',
	( nonvar(TraceR) -> recorda('$trace', on, _) ; true),
	'$clear_reconsulting',
	set_value('$consulting',Old),
	set_value('$consulting_file',OldF),
	'$cd'(OldD),
	'$current_module'(Mod,OldModule),
	'$import_to_current_module'(File, ContextModule, Imports),
	( LC == 0 -> prompt(_,'   |: ') ; true),
	H is heapused-H0, '$cputime'(TF,_), T is TF-T0,
	'$print_message'(InfLevel, loaded(EndMsg, File, Mod, T, H)),
	'$exec_initialisation_goals',
	!.

'$import_to_current_module'(File, M, Imports) :-
	recorded('$module','$module'(File,NM,Ps),_), M \= NM, !,
	'$use_preds'(Imports, Ps, NM, M).
'$import_to_current_module'(_, _, _).

'$consult_infolevel'(InfoLevel) :- nonvar(InfoLevel), !.
'$consult_infolevel'(InfoLevel) :-
	get_value('$lf_verbose',InfoLevel), !.
'$consult_infolevel'(informational).

'$start_reconsulting'(F) :-
	recorda('$reconsulted','$',_),
	recorda('$reconsulting',F,_).

'$initialization'(V) :-
	var(V), !,
	'$do_error'(instantiation_error,initialization(V)).
'$initialization'(C) :- number(C), !,
	'$do_error'(type_error(callable,C),initialization(C)).
'$initialization'(C) :- db_reference(C), !,
	'$do_error'(type_error(callable,C),initialization(C)).
'$initialization'(G) :-
	recorda('$initialisation',G,_),
	fail.
'$initialization'(_).


'$include'(V, _) :- var(V), !,
	'$do_error'(instantiation_error,include(V)).
'$include'([], _) :- !.
'$include'([F|Fs], Status) :- !,
	'$include'(F, Status),
	'$include'(Fs, Status).
'$include'(X, Status) :-
	get_value('$lf_verbose',Verbosity),
	'$find_in_path'(X,Y,include(X)),
	'$values'('$included_file',OY,Y),
	'$current_module'(Mod),
	H0 is heapused, '$cputime'(T0,_),
	( '$open'(Y,'$csult',Stream,0), !,
		'$print_message'(Verbosity, loading(including, Y)),
		'$loop'(Stream,Status), '$close'(Stream)
	;
		'$do_error'(permission_error(input,stream,Y),include(X))
	),
	H is heapused-H0, '$cputime'(TF,_), T is TF-T0,
	'$print_message'(Verbosity, loaded(included, Y, Mod, T, H)),
	set_value('$included_file',OY).

'$do_startup_reconsult'(X) :-
	( '$access_yap_flags'(15, 0) ->
	  true
	;
	  set_value('$lf_verbose',silent)
	),
	( '$find_in_path'(X,Y,reconsult(X)),
	  '$open'(Y,'$csult',Stream,0) ->
		( '$access_yap_flags'(15, 0) -> true ; '$skip_unix_comments'(Stream) ),
		'$current_module'(M), '$do_lf'(Y,M,Stream,silent,_,_), '$close'(Stream)
	;
		'$output_error_message'(permission_error(input,stream,X),reconsult(X))
	),
	( '$access_yap_flags'(15, 0) -> true ; halt).

'$skip_unix_comments'(Stream) :-
	'$peek'(Stream, 0'#), !, % 35 is ASCII for #
	'$get0_line_codes'(Stream, _),
	'$skip_unix_comments'(Stream).
'$skip_unix_comments'(_).


prolog_load_context(_, _) :-
	get_value('$consulting_file',[]), !, fail.
prolog_load_context(directory, DirName) :- 
	get_value('$consulting_file',FileName),
	(FileName = user_input ->
	  '$getcwd'(S),
	  atom_codes(DirName,S)
        ;
	  atom_codes(FileName,S),
	  '$strip_file_for_scd'(S,Dir,Unsure,Unsure),
	  atom_codes(DirName,Dir)
	).
prolog_load_context(file, FileName) :- 
	get_value('$included_file',IncFileName),
	( IncFileName = [] ->
	  get_value('$consulting_file',FileName)
        ;
           FileName = IncFileName
        ).
prolog_load_context(module, X) :-
	'$current_module'(X).
prolog_load_context(source, FileName) :-
	get_value('$consulting_file',FileName).
prolog_load_context(stream, Stream) :- 
	'$fetch_stream_alias'('$loop_stream', Stream).
prolog_load_context(term_position, Position) :- 
	'$fetch_stream_alias'('$loop_stream', Stream),
	stream_position(Stream, Position).


% if the file exports a module, then we can
% be imported from any module.
'$file_loaded'(Stream, M, Imports) :-
	'$file_name'(Stream, F),
	'$ensure_file_loaded'(F, M, Imports).

'$ensure_file_loaded'(F, M, Imports) :-
	recorded('$module','$module'(F1,NM,P),_),
	recorded('$lf_loaded','$lf_loaded'(F1,_,Age),R),
	'$same_file'(F1,F), !,
	'$use_preds'(Imports,P, NM, M).
'$ensure_file_loaded'(F, M, _) :-
	recorded('$lf_loaded','$lf_loaded'(F1,M,Age),R),
	'$same_file'(F1,F).

% if the file exports a module, then we can
% be imported from any module.
'$file_unchanged'(Stream, M, Imports) :-
	'$file_name'(Stream, F),
	'$ensure_file_unchanged'(F, M, Imports).

'$ensure_file_unchanged'(F, M, Imports) :-
	recorded('$module','$module'(F1,NM,P),_),
	recorded('$lf_loaded','$lf_loaded'(F1,_,Age),R),
	'$same_file'(F1,F), !,
	'$file_is_unchanged'(F, R, Age),
	'$use_preds'(Imports, P, NM, M).
'$ensure_file_unchanged'(F, M, _) :-
	recorded('$lf_loaded','$lf_loaded'(F1,M,Age),R),
	'$same_file'(F1,F), !,
	'$file_is_unchanged'(F, R, Age).

'$file_is_unchanged'(F, R, Age) :-
        '$file_age'(F,CurrentAge),
         ((CurrentAge = Age ; Age = -1)  -> true; erase(R), fail).



path(Path) :- findall(X,'$in_path'(X),Path).

'$in_path'(X) :- recorded('$path',Path,_),
		atom_codes(Path,S),
		( S = ""  -> X = '.' ;
		  atom_codes(X,S) ).

add_to_path(New) :- add_to_path(New,last).

add_to_path(New,Pos) :-
	atom(New), !,
	'$check_path'(New,Str),
	atom_codes(Path,Str),
	'$add_to_path'(Path,Pos).

'$add_to_path'(New,_) :- recorded('$path',New,R), erase(R), fail.
'$add_to_path'(New,last) :- !, recordz('$path',New,_).
'$add_to_path'(New,first) :- recorda('$path',New,_).

remove_from_path(New) :- '$check_path'(New,Path),
			recorded('$path',Path,R), erase(R).

'$check_path'(At,SAt) :- atom(At), !, atom_codes(At,S), '$check_path'(S,SAt).
'$check_path'([],[]).
'$check_path'([Ch],[Ch]) :- '$dir_separator'(Ch), !.
'$check_path'([Ch],[Ch,A]) :- !, integer(Ch), '$dir_separator'(A).
'$check_path'([N|S],[N|SN]) :- integer(N), '$check_path'(S,SN).

% add_multifile_predicate when we start consult
'$add_multifile'(Name,Arity,Module) :-
	get_value('$consulting_file',File),
	'$add_multifile'(File,Name,Arity,Module).

'$add_multifile'(File,Name,Arity,Module) :-
	recorded('$multifile_defs','$defined'(File,Name,Arity,Module), _), !,
	'$print_message'(warning,declaration((multifile Module:Name/Arity),ignored)).
'$add_multifile'(File,Name,Arity,Module) :-
	recordz('$multifile_defs','$defined'(File,Name,Arity,Module),_), !,
	fail.
'$add_multifile'(File,Name,Arity,Module) :-
	recorded('$mf','$mf_clause'(File,Name,Arity,Module,Ref),R),
	erase(R),
	'$erase_clause'(Ref,Module),
	fail.
'$add_multifile'(_,_,_,_).

% retract old multifile clauses for current file.
'$remove_multifile_clauses'(FileName) :-
	recorded('$multifile_defs','$defined'(FileName,_,_,_),R1),
	erase(R1),
	fail.
'$remove_multifile_clauses'(FileName) :-
	recorded('$mf','$mf_clause'(FileName,_,_,Module,Ref),R),
	'$erase_clause'(Ref, Module),
	erase(R),
	fail.
'$remove_multifile_clauses'(_).