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yap-6.3/pl/yio.yap
2011-05-02 23:28:59 +01:00

363 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: yio.yap *
* Last rev: *
* mods: *
* comments: Input output predicates *
* *
*************************************************************************/
/* stream predicates */
/* check whether a list of options is valid */
'$check_io_opts'(V,G) :- var(V), !,
'$do_error'(instantiation_error,G).
'$check_io_opts'([],_) :- !.
'$check_io_opts'([H|_],G) :- var(H), !,
'$do_error'(instantiation_error,G).
'$check_io_opts'([Opt|T],G) :- !,
'$check_opt'(G,Opt,G),
'$check_io_opts'(T,G).
'$check_io_opts'(T,G) :-
'$do_error'(type_error(list,T),G).
'$check_opt'(read_term(_,_),Opt,G) :-
'$check_opt_read'(Opt, G).
'$check_opt'(stream_property(_,_),Opt,G) :-
'$check_opt_sp'(Opt, G).
'$check_opt'(yap_flag(_,_),Opt,G) :-
'$check_opt_write'(Opt, G).
'$check_opt_read'(variables(_), _) :- !.
'$check_opt_read'(variable_names(_), _) :- !.
'$check_opt_read'(singletons(_), _) :- !.
'$check_opt_read'(syntax_errors(T), G) :- !,
'$check_read_syntax_errors_arg'(T, G).
'$check_opt_read'(term_position(_), _) :- !.
'$check_opt_read'(module(_), _) :- !.
'$check_opt_read'(A, G) :-
'$do_error'(domain_error(read_option,A),G).
'$check_opt_sp'(file_name(_), _) :- !.
'$check_opt_sp'(mode(_), _) :- !.
'$check_opt_sp'(input, _) :- !.
'$check_opt_sp'(output, _) :- !.
'$check_opt_sp'(alias(_), _) :- !.
'$check_opt_sp'(position(_), _) :- !.
'$check_opt_sp'(end_of_stream(_), _) :- !.
'$check_opt_sp'(eof_action(_), _) :- !.
'$check_opt_sp'(reposition(_), _) :- !.
'$check_opt_sp'(type(_), _) :- !.
'$check_opt_sp'(bom(_), _) :- !.
'$check_opt_sp'(encoding(_), _) :- !.
'$check_opt_sp'(representation_errors(_), _) :- !.
'$check_opt_sp'(A, G) :-
'$do_error'(domain_error(stream_property,A),G).
'$check_read_syntax_errors_arg'(X, G) :- var(X), !,
'$do_error'(instantiation_error,G).
'$check_read_syntax_errors_arg'(dec10,_) :- !.
'$check_read_syntax_errors_arg'(fail,_) :- !.
'$check_read_syntax_errors_arg'(error,_) :- !.
'$check_read_syntax_errors_arg'(quiet,_) :- !.
'$check_read_syntax_errors_arg'(X,G) :-
'$do_error'(domain_error(read_option,syntax_errors(X)),G).
'$check_boolean'(X, _, _, G) :- var(X), !,
'$do_error'(instantiation_error,G).
'$check_boolean'(true,_,_,_) :- !.
'$check_boolean'(false,_,_,_) :- !.
'$check_boolean'(X,B,T,G) :-
'$do_error'(domain_error(B,T),G).
open_pipe_streams(Read, Write) :-
(
'$undefined'(pipe(_,_),unix)
->
load_files(library(unix), [silent(true),if(not_loaded)])
;
true
),
unix:pipe(Read, Write).
fileerrors :- '$swi_set_prolog_flag'(fileerrors, true).
nofileerrors :- '$swi_set_prolog_flag'(fileerrors, false).
exists(F) :- access_file(F,exist).
/* Term IO */
read(T) :-
'$read'(false,T,_,_,_,Err),
(nonvar(Err) ->
print_message(error,Err), fail
;
true
).
read(Stream,T) :-
'$read'(false,T,_,_,_,Err,Stream),
(nonvar(Err) ->
print_message(error,Err), fail
;
true
).
read_term(T, Options) :-
'$check_io_opts'(Options,read_term(T, Options)),
current_input(S),
'$preprocess_read_terms_options'(Options,Module),
'$read_vars'(S,T,Module,Pos,VL,'|: '),
'$postprocess_read_terms_options'(Options, T, VL, Pos).
read_term(Stream, T, Options) :-
'$check_io_opts'(Options,read_term(T, Options)),
'$preprocess_read_terms_options'(Options,Module),
'$read_vars'(Stream,T,Module,Pos,VL,'|: '),
'$postprocess_read_terms_options'(Options, T, VL, Pos).
%
% support flags to read
%
'$preprocess_read_terms_options'([],_).
'$preprocess_read_terms_options'([syntax_errors(NewVal)|L],Mod) :- !,
'$get_read_error_handler'(OldVal),
set_value('$read_term_error_handler', OldVal),
'$set_read_error_handler'(NewVal),
'$preprocess_read_terms_options'(L,Mod).
'$preprocess_read_terms_options'([module(Mod)|L],Mod) :- !,
'$preprocess_read_terms_options'(L,Mod).
'$preprocess_read_terms_options'([_|L],Mod) :-
'$preprocess_read_terms_options'(L,Mod).
'$postprocess_read_terms_options'([], _, _, _).
'$postprocess_read_terms_options'([H|Tail], T, VL, Pos) :- !,
'$postprocess_read_terms_option'(H, T, VL, Pos),
'$postprocess_read_terms_options_list'(Tail, T, VL, Pos).
'$postprocess_read_terms_options_list'([], _, _, _).
'$postprocess_read_terms_options_list'([H|Tail], T, VL, Pos) :-
'$postprocess_read_terms_option'(H, T, VL, Pos),
'$postprocess_read_terms_options_list'(Tail, T, VL, Pos).
'$postprocess_read_terms_option'(syntax_errors(_), _, _, _) :-
get_value('$read_term_error_handler', OldVal),
'$set_read_error_handler'(OldVal).
'$postprocess_read_terms_option'(variable_names(Vars), _, VL, _) :-
'$read_term_non_anonymous'(VL, Vars).
'$postprocess_read_terms_option'(singletons(Val), T, VL, _) :-
'$singletons_in_term'(T, Val1),
'$fetch_singleton_names'(Val1,VL,Val).
'$postprocess_read_terms_option'(variables(Val), T, _, _) :-
'$variables_in_term'(T, [], Val).
'$postprocess_read_terms_option'(term_position(Pos), _, _, Pos).
'$postprocess_read_terms_option'(module(_), _, _, _).
%'$postprocess_read_terms_option'(cycles(Val), _, _).
'$read_term_non_anonymous'([], []).
'$read_term_non_anonymous'([[S|V]|VL], [Name=V|Vars]) :-
atom_codes(Name,S),
'$read_term_non_anonymous'(VL, Vars).
% problem is what to do about _ singletons.
% no need to do ordering, the two lists already come ordered.
'$fetch_singleton_names'([], _, []).
'$fetch_singleton_names'([_|_], [], []) :- !.
'$fetch_singleton_names'([V1|Ss], [[Na|V2]|Ns], ONs) :-
V1 == V2, !,
'$add_singleton_if_no_underscore'(Na,V2,NSs,ONs),
'$fetch_singleton_names'(Ss, Ns, NSs).
'$fetch_singleton_names'([V1|Ss], [[_|V2]|Ns], NSs) :-
V1 @> V2, !,
'$fetch_singleton_names'([V1|Ss], Ns, NSs).
'$fetch_singleton_names'([_V1|Ss], Ns, NSs) :-
% V1 @> V2,
'$fetch_singleton_names'(Ss, Ns, NSs).
'$add_singleton_if_no_underscore'([95|_],_,NSs,NSs) :- !.
'$add_singleton_if_no_underscore'(Na,V2,NSs,[(Name=V2)|NSs]) :-
atom_codes(Name, Na).
/* meaning of flags for '$write' is
1 quote illegal atoms
2 ignore operator declarations
4 output '$VAR'(N) terms as A, B, C, ...
8 use portray(_)
flags are defined in yapio.h
*/
display(T) :-
current_output(Out),
write_term(Out, T, [ignore_ops(true)]).
display(Stream, T) :-
write_term(Term, T, [ignore_ops(true)]).
format(T) :-
format(T, []).
writeln(T) :-
write(T),
nl.
/* interface to user portray */
'$portray'(T) :-
\+ '$undefined'(portray(_),user),
'$system_catch'(call(portray(T)),user,Error,user:'$Error'(Error)), !,
set_value('$portray',true), fail.
'$portray'(_) :- set_value('$portray',false), fail.
/* character I/O */
ttyget(N) :- get(user_input,N).
ttyget0(N) :- get0(user_input,N).
ttyskip(N) :- N1 is N, '$skip'(user_input,N1).
ttyput(N) :- N1 is N, put(user_output,N1).
ttynl :- nl(user_output).
current_line_number(N) :-
current_input(Stream),
line_count(Stream, N).
current_line_number(Stream,N) :-
line_count(Stream, N).
stream_position(Stream, Position) :-
stream_property(Stream, position(Position)).
stream_position(Stream, Position, NewPosition) :-
stream_property(Stream, position(Position)),
set_stream_position(Stream, NewPosition).
at_end_of_line :-
current_input(S),
at_end_of_line(S).
at_end_of_line(S) :-
current_stream(S, end_of_stream(past)), !.
at_end_of_line(S) :-
peek(S,N), ( N = 10 -> true ; N = -1).
consult_depth(LV) :- '$show_consult_level'(LV).
current_char_conversion(X,Y) :-
var(X), !,
'$all_char_conversions'(List),
'$fetch_char_conversion'(List,X,Y).
current_char_conversion(X,Y) :-
'$current_char_conversion'(X,Y).
'$fetch_char_conversion'([X,Y|_],X,Y).
'$fetch_char_conversion'([_,_|List],X,Y) :-
'$fetch_char_conversion'(List,X,Y).
current_stream(File, Opts, Stream) :-
'$current_stream'(File, Opts, Stream).
'$extend_file_search_path'(P) :-
atom_codes(P,S),
'$env_separator'(ES),
'$split_for_path'(S,0'=,ES,Paths), %'
'$add_file_search_paths'(Paths).
'$split_for_path'([], _, _, []).
'$split_for_path'(S, S1, S2, [A1=A2|R]) :-
'$fetch_first_path'(S, S1, A1, SR1),
'$fetch_second_path'(SR1, S2, A2, SR),
'$split_for_path'(SR, S1, S2, R) .
'$fetch_first_path'([S1|SR],S1,[],SR) :- !.
'$fetch_first_path'([C|S],S1,[C|F],SR) :-
'$fetch_first_path'(S,S1,F,SR).
'$fetch_second_path'([],_,[],[]).
'$fetch_second_path'([S1|SR],S1,[],SR) :- !.
'$fetch_second_path'([C|S],S1,[C|A2],SR) :-
'$fetch_second_path'(S,S1,A2,SR).
'$add_file_search_paths'([]).
'$add_file_search_paths'([NS=DS|Paths]) :-
atom_codes(N,NS),
atom_codes(D,DS),
assert(user:file_search_path(N,D)),
'$add_file_search_paths'(Paths).
'$format@'(Goal,Out) :-
with_output_to(codes(Out), Goal).
sformat(String, Form, Args) :-
format(codes(String, []), Form, Args).
write_depth(T,L) :- write_depth(T,L,_).
%% stream_position_data(?Field, +Pos, ?Date)
%
% Extract values from stream position objects. '$stream_position' is
% of the format '$stream_position'(Byte, Char, Line, LinePos)
stream_position_data(Prop, Term, Value) :-
nonvar(Prop), !,
( '$stream_position_field'(Prop, Pos)
-> arg(Pos, Term, Value)
; throw(error(domain_error(stream_position_data, Prop)))
).
stream_position_data(Prop, Term, Value) :-
'$stream_position_field'(Prop, Pos),
arg(Pos, Term, Value).
'$stream_position_field'(char_count, 1).
'$stream_position_field'(line_count, 2).
'$stream_position_field'(line_position, 3).
'$stream_position_field'(byte_count, 4).
'$default_expand'(Expand) :-
nb_getval('$open_expands_filename',Expand).
'$set_default_expand'(true) :- !,
nb_setval('$open_expands_filename',true).
'$set_default_expand'(false) :- !,
nb_setval('$open_expands_filename',false).
'$set_default_expand'(V) :- !,
'$do_error'(domain_error(flag_value,V),yap_flag(open_expands_file_name,X)).
prolog_file_name(File, PrologFileName) :-
var(File), !,
'$do_error'(instantiation_error, prolog_file_name(File, PrologFileName)).
prolog_file_name(user, Out) :- !, Out = user.
prolog_file_name(File, PrologFileName) :-
atom(File), !,
operating_system_support:true_file_name(File, PrologFileName).
prolog_file_name(File, PrologFileName) :-
'$do_error'(type_error(atom,T), prolog_file_name(File, PrologFileName)).
'$codes_to_chars'(String0, String, String0) :- String0 == String, !.
'$codes_to_chars'(String0, [Code|String], [Char|Chars]) :-
atom_codes(Char, [Code]),
'$codes_to_chars'(String0, String, Chars).