#!/usr/bin/perl -w
use strict;
use Algorithm::Diff qw( traverse_sequences );
exit main();
{
my( $outState, %markUp, %htmlEnt );
BEGIN {
%markUp= (
same => ['',''],
new => ['',''],
old => ['',''],
);
%htmlEnt= ( "<"=>"lt", "&"=>"amp", ">"=>"gt",
"["=>"#91", "]"=>"#93" );
}
sub output {
my( $style, $text )= @_;
if( ! defined $outState ) {
print $markUp{ $outState= $style }[0];
} elsif( $style ne $outState ) {
print $markUp{$outState}[1], $markUp{$style}[0];
$outState= $style;
}
$text =~ s#([][<>&])#&$htmlEnt{$1};#g;
$text =~ s#\n#
\n#g;
print $text;
}
}
sub flush {
my( $meth, $rOld, $rNew )= @_;
return if "" eq $$rOld && "" eq $$rNew;
if( "" eq $$rOld ) {
output( "new", $$rNew );
} elsif( "" eq $$rNew ) {
output( "old", $$rOld );
} elsif( ! $meth ) {
output( "old", $$rOld );
output( "new", $$rNew );
} else {
my( $meth, $old, $new )= &$meth( $rOld, $rNew );
compare( $meth, $old, $new );
}
$$rOld= $$rNew= "";
}
sub compare {
my( $meth, $old, $new )= @_;
my( $oldTemp, $newTemp )= ( "", "" );
traverse_sequences( $old, $new, {
MATCH => sub { flush( $meth, \$oldTemp, \$newTemp );
output( "same", $old->[$_[0]] ) },
DISCARD_A => sub { $oldTemp .= $old->[$_[0]] },
DISCARD_B => sub { $newTemp .= $new->[$_[1]] },
} );
flush( $meth, \$oldTemp, \$newTemp );
}
sub SentToWord {
my( $rOld, $rNew )= @_;
return(
undef,
[ split /(?<=\s)(?=\S)/, $$rOld ],
[ split /(?<=\s)(?=\S)/, $$rNew ],
);
}
sub ParaToSent {
my( $rOld, $rNew )= @_;
return(
\&SentToWord,
[ split /(?<=[.?!]\s)/, $$rOld ],
[ split /(?<=[.?!]\s)/, $$rNew ],
);
}
sub main {
die "Usage: $0 old new >dif\n" unless 2 == @ARGV;
my( $old, $new );
{ local($/,@ARGV)= ('',$ARGV[0]); $old= [<>]; }
{ local($/,@ARGV)= ('',$ARGV[1]); $new= [<>]; }
compare( \&ParaToSent, $old, $new );
output( "same", "" );
exit 0;
}