Files
mercury/samples/diff/filter.m
Julien Fischer 59933b6530 Update the syntax in diff sample.
samples/*.m:
    As above.
2015-12-15 01:44:08 +11:00

122 lines
3.8 KiB
Mathematica

%-----------------------------------------------------------------------------%
% vim: ft=mercury ts=4 sw=4 et wm=0 tw=0
%-----------------------------------------------------------------------------%
% Copyright (C) 1998, 2006 The 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.
%-----------------------------------------------------------------------------%
%
% Main author: bromage
%
% This module contains code to filter the diff before output, based on
% the command-line options presented.
%
% At the moment, only one option is handled: --ignore-blank-lines.
% This causes edits to be dropped if they contain changes which only
% add, delete or change blank lines.
%
% TO DO: What exactly is a blank line, and does its definition change
% if --ignore-space-change or --ignore-all-space have been
% specified? At the moment, we define a blank line to be a line
% containing zero or more whitespace characters. Check if this is
% correct or not.
%
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%
:- module filter.
:- interface.
:- import_module difftype.
:- import_module file.
:- import_module io.
%-----------------------------------------------------------------------------%
:- pred filter_diff(file::in, file::in, diff::in, diff::out,
io::di, io::uo) is det.
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%
:- implementation.
:- import_module globals.
:- import_module options.
:- import_module bool.
:- import_module char.
:- import_module int.
:- import_module list.
:- import_module pair.
:- import_module string.
%-----------------------------------------------------------------------------%
filter_diff(File1, File2, !Diff, !IO) :-
globals.io_lookup_bool_option(ignore_blank_lines, FilterBlank, !IO),
(
% If we didn't request a filter, skip this pass.
FilterBlank = no
;
FilterBlank = yes,
filter.blank_lines(!.Diff, File1, File2, !:Diff)
).
:- pred filter.blank_lines(diff::in, file::in, file::in, diff::out) is det.
filter.blank_lines([], _, _, []).
filter.blank_lines([Edit | Diff0], File1, File2, Diff) :-
filter.blank_lines(Diff0, File1, File2, Diff1),
(
Edit = add(_, Y1 - Y2),
( if range_has_only_blank_lines(Y1, Y2, File2) then
Diff = Diff1
else
Diff = [Edit | Diff1]
)
;
Edit = delete(X1 - X2, _),
( if range_has_only_blank_lines(X1, X2, File1) then
Diff = Diff1
else
Diff = [Edit | Diff1]
)
;
Edit = change(X1 - X2, Y1 - Y2),
( if
range_has_only_blank_lines(X1, X2, File1),
range_has_only_blank_lines(Y1, Y2, File2)
then
Diff = Diff1
else
Diff = [Edit | Diff1]
)
).
%-----------------------------------------------------------------------------%
:- pred range_has_only_blank_lines(int::in, int::in, file::in) is semidet.
range_has_only_blank_lines(First, Last, File) :-
(
First < Last
=>
(
file.get_line(File, First, Line),
string.to_char_list(Line, Chars),
all [C] (
list.member(C, Chars)
=>
char.is_whitespace(C)
),
range_has_only_blank_lines(First + 1, Last, File)
)
).
%-----------------------------------------------------------------------------%
:- end_module filter.
%-----------------------------------------------------------------------------%