1		% (c) 2009-2023 Lehrstuhl fuer Softwaretechnik und Programmiersprachen,
2		% Heinrich Heine Universitaet Duesseldorf
3		% This software is licenced under EPL 1.0 (http://www.eclipse.org/org/documents/epl-v10.html)
4
5		:- module(tools_io,[safe_open_file/4,
6		intelligent_open/4,
7		safe_intelligent_open_file/3, safe_intelligent_open_file/4,
8		safe_intelligent_close_file/2,
9		with_open_stream_to_codes/4,
10		read_byte_line/2,
11		read_byte_word/2,
12		put_bytes/2]).
13
14		:- meta_predicate with_open_stream_to_codes(0,*,*,*).
15
16		:- use_module(module_information).
17		:- module_info(group,infrastructure).
18		:- module_info(description,'This module contains file io helper predicates.').
19
20		:- use_module(error_manager).
21		:- use_module(probsrc(tools_strings), [ajoin/2]).
22
23		safe_open_file(Filename,_,_,_) :-
24		(Filename=[] ; \+ atom(Filename)),!,
25		add_error(open_file,'Filename must be an atom:',Filename),fail.
26		safe_open_file(Filename,Mode,Stream,Options) :-
27		%print(opening(Filename)),nl,
28		catch(open(Filename,Mode,Stream,Options), error(A,B),
29		(ajoin(['Exception occurred opening file \'',Filename,
30		'\' (mode: ',Mode, ', options: ',Options,') :'],Msg),
31		add_error(open_file,Msg,error(A,B)),fail)).
32
33
34		safe_intelligent_open_file(Filename,Mode,Stream) :-
35		safe_intelligent_open_file(Filename,Mode,Stream,[encoding(utf8)]).
36		safe_intelligent_open_file(Filename,Mode,Stream,Options) :-
37		%print(opening(Filename)),nl,
38		catch(intelligent_open(Filename,Mode,Stream,Options), % utf8
39		error(A,B),
40		(add_error(open_file,'Exception occurred opening file:',error(A,B)),fail)).
41
42		intelligent_open(user_error,Mode,Stream,_) :- (Mode=append ; Mode=write), !, Stream=user_error.
43		intelligent_open(stderr,Mode,Stream,_) :- (Mode=append ; Mode=write), !, Stream=user_error.
44		intelligent_open(user_output,Mode,Stream,_) :- (Mode=append ; Mode=write), !, Stream=user_output.
45		intelligent_open(stdout,Mode,Stream,_) :- (Mode=append ; Mode=write), !, Stream=user_output.
46		intelligent_open(File,Mode,Stream,Options) :- open(File,Mode,Stream,Options).
47
48		% use if you have called safe_intelligent_open_file with alias(A) in options and want to call close(A)
49		safe_intelligent_close_file(user_error,_) :- !.
50		safe_intelligent_close_file(stderr,_) :- !.
51		safe_intelligent_close_file(user_output,_) :- !.
52		safe_intelligent_close_file(stdout,_) :- !.
53		safe_intelligent_close_file(_,Stream) :- close(Stream).
54
55
56		:- use_module(library(codesio), [with_output_to_codes/4]).
57		% Variant of with_output_to_codes that preserves the current output stream instead of replacing it with the codes stream.
58		% This ensures that debug prints inside Goal aren't redirected into the codes by accident.
59		with_open_stream_to_codes(Goal, Stream, S0, S) :-
60		current_output(CurrentOutput),
61		with_output_to_codes((set_output(CurrentOutput), Goal), Stream, S0, S).
62
63
64		% a utility to read bytes of a binary stream until the end of line
65		% stream is obtained e.g. by open(File,read,Stream,[type(binary)])
66		read_byte_line(Stream,Res) :- read_bytes_until(Stream,[10],Res).
67
68		% a utility to read bytes of a binary stream until the end of line, eof, tab or space
69		read_byte_word(Stream,Res) :- read_bytes_until(Stream,[8,10,32],Res).
70
71		:- use_module(library(ordsets),[ord_member/2]).
72		read_bytes_until(Stream,EndCodes,Res) :-
73		get_byte(Stream,Code),
74		(ord_member(Code,EndCodes) -> Res=[]
75		; Code = 13 -> read_bytes_until(Stream,EndCodes,Res)
76		; Code = -1 -> Res = [] % end of file
77		; Res = [Code|T],
78		read_bytes_until(Stream,EndCodes,T)
79		).
80
81
82		% utility to write a sequence of bytes to a binary stream
83		put_bytes(_,[]).
84		put_bytes(Stream,[H|T]) :- put_byte(Stream,H), put_bytes(Stream,T).