/************************************************************************* * * * YAP Prolog * * * * Yap Prolog was developed at NCCUP - Universidade do Porto * * * * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 * * * ************************************************************************** * * * File: charsio.yap * * Last rev: 5/12/99 * * mods: * * comments: I/O on character strings * * * *************************************************************************/ :- module(charsio, [ format_to_chars/3, format_to_chars/4, write_to_chars/3, write_to_chars/2, atom_to_chars/3, atom_to_chars/2, number_to_chars/3, number_to_chars/2, read_from_chars/2, open_chars_stream/2, with_output_to_chars/2, with_output_to_chars/3, with_output_to_chars/4, term_to_atom/2 ]). :- use_module(library(memfile)). :- meta_predicate(with_output_to_chars(0,?)). :- meta_predicate(with_output_to_chars(0,-,?)). :- meta_predicate(with_output_to_chars(0,-,?,?)). format_to_chars(Format, Args, Codes) :- format(codes(Codes), Format, Args). format_to_chars(Format, Args, OUT, L0) :- format(codes(OUT, L0), Format, Args). write_to_chars(Term, Codes) :- format(codes(Codes), '~w', [Term]). write_to_chars(Term, Out, Tail) :- format(codes(Out,Tail),'~w',[Term]). atom_to_chars(Atom, OUT) :- atom_codes(Atom, OUT). atom_to_chars(Atom, L0, OUT) :- format(codes(L0, OUT), '~a', [Atom]). number_to_chars(Number, OUT) :- number_codes(Number, OUT). number_to_chars(Number, L0, OUT) :- var(Number), !, throw(error(instantiation_error,number_to_chars(Number, L0, OUT))). number_to_chars(Number, L0, OUT) :- number(Number), !, format(codes(L0, OUT), '~w', [Number]). number_to_chars(Number, L0, OUT) :- throw(error(type_error(number,Number),number_to_chars(Number, L0, OUT))). open_chars_stream(Codes, Stream) :- open_chars_stream(Codes, Stream, ''). open_chars_stream(Codes, Stream, Postfix) :- new_memory_file(MF), open_memory_file(MF, write, Out), format(Out, '~s~w', [Codes, Postfix]), close(Out), open_memory_file(MF, read, Stream, [ free_on_close(true) ]). with_output_to_chars(Goal, Codes) :- with_output_to(codes(Codes), Goal). with_output_to_chars(Goal, Codes, L0) :- with_output_to(codes(Codes, L0), Goal). %% with_output_to_chars(:Goal, -Stream, -Codes, ?Tail) is det. % % As with_output_to_chars/2, but Stream is unified with the % temporary stream. with_output_to_chars(Goal, Stream, Codes, Tail) :- with_output_to(codes(Codes, Tail), with_stream(Stream, Goal)). with_stream(Stream, Goal) :- current_output(Stream), call(Goal).