
(********************************************************************)
(*                                                                  *)
(*  stdio.s7i     Standard input and output via files               *)
(*  Copyright (C) 1989 - 2011  Thomas Mertes                        *)
(*                                                                  *)
(*  This file is part of the Seed7 Runtime Library.                 *)
(*                                                                  *)
(*  The Seed7 Runtime Library is free software; you can             *)
(*  redistribute it and/or modify it under the terms of the GNU     *)
(*  Lesser General Public License as published by the Free Software *)
(*  Foundation; either version 2.1 of the License, or (at your      *)
(*  option) any later version.                                      *)
(*                                                                  *)
(*  The Seed7 Runtime Library is distributed in the hope that it    *)
(*  will be useful, but WITHOUT ANY WARRANTY; without even the      *)
(*  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR *)
(*  PURPOSE.  See the GNU Lesser General Public License for more    *)
(*  details.                                                        *)
(*                                                                  *)
(*  You should have received a copy of the GNU Lesser General       *)
(*  Public License along with this program; if not, write to the    *)
(*  Free Software Foundation, Inc., 51 Franklin Street,             *)
(*  Fifth Floor, Boston, MA  02110-1301, USA.                       *)
(*                                                                  *)
(********************************************************************)


include "file.s7i";
include "null_file.s7i";
include "external_file.s7i";
include "enable_io.s7i";


const func external_file: INIT_STD_FILE (ref clib_file: primitive_file,
    in string: fileName) is func
  result
    var external_file: standardFile is external_file.value;
  begin
    standardFile.ext_file := primitive_file;
    standardFile.name := fileName;
  end func;


(**
 *  Standard input file of the operating system.
 *  The file IN is initialized with STD_IN.
 *)
var external_file: STD_IN is  INIT_STD_FILE(CLIB_INPUT,  "STD_IN");


(**
 *  Standard output file of the operating system.
 *  The file OUT is initialized with STD_OUT.
 *)
var external_file: STD_OUT is INIT_STD_FILE(CLIB_OUTPUT, "STD_OUT");


(**
 *  Standard error file of the operating system.
 *)
var external_file: STD_ERR is INIT_STD_FILE(CLIB_ERROR,  "STD_ERR");


(**
 *  Standard input file used by read and readln.
 *  Assigning a file to ''IN'' changes the source of the functions
 *  [[#read(inout_string)|read]] and [[#readln|readln]].
 *)
var file: IN is STD_IN;


(**
 *  Standard output file used by write and writeln.
 *  Assigning a file to OUT changes the destination fo the
 *  functions [[#write(in_string)|write]] and [[#writeln|writeln]].
 *)
var file: OUT is STD_OUT;


var file: PROT_OUTFILE is STD_OUT;


(* Set of operations for IN and OUT *)


(**
 *  Write a string to the standard output file ([[#OUT|OUT]]).
 *)
const proc: write (in string: stri) is func
  begin
    write(OUT, stri);
  end func;


(**
 *  Write end-of-line to the standard output file.
 *  The file type of [[#OUT|OUT]] decides how writing end-of-line is done.
 *  It can be done by writing '\n', but other solutions are also
 *  possible.
 *)
const proc: writeln is func
  begin
    writeln(OUT);
  end func;


(**
 *  Write a string followed by end-of-line to the standard output.
 *  The file type of [[#OUT|OUT]] decides how writing end-of-line is done.
 *  It can be done by writing '\n', but other solutions are also
 *  possible.
 *)
const proc: writeln (in string: stri) is func
  begin
    writeln(OUT, stri);
  end func;


(**
 *  Read a word from the standard input file ([[#IN|IN]]).
 *  Before reading the word it skips spaces and tabs. The function
 *  accepts words ending with " ", "\t", end-of-line or [[char#EOF|EOF]].
 *  The word ending characters are not copied into the string.
 *  When the function is left [[#IN|IN]].bufferChar contains the
 *  word ending character (' ', '\t', '\n' or [[char#EOF|EOF]]).
 *)
const proc: read (inout string: aVar) is func
  begin
    read(IN, aVar);
  end func;


(**
 *  Read a word from the standard input file ([[#IN|IN]]) or use ''defaultValue''.
 *  Before reading the word it skips spaces and tabs. The function
 *  accepts words ending with " ", "\t", end-of-line or [[char#EOF|EOF]].
 *  When the word is empty ''defaultValue'' is assigned to ''aVar''.
 *  The word ending characters are not copied into the string.
 *  When the function is left [[#IN|IN]].bufferChar contains the
 *  word ending character (' ', '\t', '\n' or [[char#EOF|EOF]]).
 *)
const proc: read (inout string: aVar, in string: defaultValue) is func
  begin
    read(IN, aVar, defaultValue);
  end func;


(**
 *  Read a line from the standard input file ([[#IN|IN]]).
 *  The function reads a string up to end-of-line or [[char#EOF|EOF]].
 *  The line ending characters are not copied into the string.
 *  When the function is left [[#IN|IN]].bufferChar contains the
 *  line ending character ('\n' or [[char#EOF|EOF]]).
 *)
const proc: readln (inout string: aVar) is func
  begin
    readln(IN, aVar);
  end func;


(**
 *  Read a line from the standard input file ([[#IN|IN]]) or use ''defaultValue''.
 *  The function reads a string up to end-of-line or [[char#EOF|EOF]].
 *  When the line is empty ''defaultValue'' is assigned to ''aVar''.
 *  The line ending characters are not copied into the string.
 *  When the function is left [[#IN|IN]].bufferChar contains the
 *  line ending character ('\n' or [[char#EOF|EOF]]).
 *)
const proc: readln (inout string: aVar, in string: defaultValue) is func
  begin
    readln(IN, aVar, defaultValue);
  end func;


(**
 *  Discard a line from the standard input file ([[#IN|IN]]).
 *  The function discards characters up to end-of-line or [[char#EOF|EOF]].
 *  When the function is left [[#IN|IN]].bufferChar contains the
 *  line ending character ('\n' or [[char#EOF|EOF]]).
 *)
const proc: readln is func
  local
    var string: stri is "";
  begin
    stri := getln(IN);
  end func;
