Files
mercury/samples/diff/file.m
1995-05-24 04:53:43 +00:00

93 lines
2.9 KiB
Mathematica

%-----------------------------------------------------------------------------%
% Copyright (C) 1995 University of Melbourne.
% This file may only be copied under the terms of the GNU General
% Public License - see the file COPYING in the Mercury distribution.
%-----------------------------------------------------------------------------%
:- module file.
:- interface.
:- import_module io, list, string.
:- type file.
:- pred file__read_file(string, file, io__state, io__state).
:- mode file__read_file(in, out, di, uo) is det.
:- pred file__read_input(file, io__state, io__state).
:- mode file__read_input(out, di, uo) is det.
:- pred file__get_line(file, int, string).
:- mode file__get_line(in, in, out) is semidet.
:- pred file__get_numlines(file, int).
:- mode file__get_numlines(in, out) is det.
:- pred file__to_list(file, list(string)).
:- mode file__to_list(in, out) is det.
%-----------------------------------------------------------------------------%
:- implementation.
:- import_module array, require, int.
%-----------------------------------------------------------------------------%
:- type file == array(string).
file__read_file(FileName, Contents) -->
io__open_input(FileName, Res),
( { Res = ok(InputStream) },
file__read_stream(InputStream, Contents),
io__close_input(InputStream)
; { Res = error(Error) },
{ io__error_message(Error, Msg) },
{ error(Msg) }
).
file__read_input(Contents) -->
io__input_stream(InputStream),
file__read_stream(InputStream, Contents).
:- pred file__read_stream(io__input_stream, file, io__state, io__state).
:- mode file__read_stream(in, out, di, uo) is det.
file__read_stream(Stream, File) -->
file__read_stream2(Stream, 0, _, File).
:- pred file__read_stream2(io__input_stream, int, int, file,
io__state, io__state).
:- mode file__read_stream2(in, in, out, out, di, uo) is det.
file__read_stream2(Stream, LinesIn, LinesOut, File) -->
io__read_line(Stream, Res),
( { Res = eof },
( { LinesIn < 1 } ->
{ LinesOut = 1 }
;
{ LinesOut = LinesIn }
),
{ array__init(1, LinesOut, "", File) }
; { Res = ok(Line) },
{ LinesIn1 is LinesIn+1 },
{ string__from_char_list(Line, Line1) },
file__read_stream2(Stream, LinesIn1, LinesOut, File1),
{ array__set(File1, LinesIn1, Line1, File) }
; { Res = error(Error) },
{ io__error_message(Error, Msg) },
{ error(Msg) }
).
%-----------------------------------------------------------------------------%
file__get_line(File, LineNo, Line) :-
array__get_bounds(File, Low, High),
Low <= LineNo, LineNo <= High,
array__lookup(File, LineNo, Line).
file__get_numlines(File, NumLines) :-
array__bounds(File, _, NumLines).
file__to_list(File, List) :-
array__to_list(File, List).
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%