File Coverage

blib/lib/Template/Reverse.pm

Criterion	Covered	Total	%
statement	54	54	100.0
branch	6	6	100.0
condition	1	3	33.3
subroutine	10	10	100.0
pod	1	1	100.0
total	72	74	97.3

package Template::Reverse;

# ABSTRACT: A template generator getting different parts between pair of text
use Moo;
use utf8;
use Template::Reverse::Util;
use constant::Atom qw(WILDCARD BOF EOF);
use Algorithm::Diff qw(sdiff);
use List::Util qw(max min);
require Exporter;
our @ISA = 'Exporter';
our @EXPORT = qw(WILDCARD BOF EOF);

our $VERSION = '0.202'; # VERSION


has 'sidelen' => (
    is=>'rw',
    default => sub{return 10;}
);


sub detect{
    my ($self,$arr1,$arr2,$sidelen) = @_;
    $sidelen ||= $self->sidelen();
    $arr1 = [BOF, @{$arr1}, EOF];
    $arr2 = [BOF, @{$arr2}, EOF];
    my $diff = _diff($arr1,$arr2);
    my $pattern = _detect($diff, $sidelen);
    return $pattern;
}

### internal functions

sub _detect{
    my ($diff, $sidelen) = @_;
    my @parts = partition_by(sub{$_[0]==WILDCARD}, @{$diff});
    my @each_parts = partition(3, 2, @parts);

    my @res;
    foreach my $part (@each_parts){
        my($pre, $wc, $post) = @{$part};
        my @pre = @{$pre};
        my @post = @{$post};
        @pre = splice(@pre, max(0-@pre,-$sidelen));
        @post = splice(@post, 0, min(0+@post,$sidelen));
        push(@res, {pre=>\@pre, post=>\@post});
    }
    return \@res;
}

sub _diff{
    my ($a,$b) = @_;
    my @d = sdiff($a,$b);
    my @rr;
    my $idx = 0;
    for my $r (@d){
        if( $r->[0] eq 'u' ){
            push(@rr,$a->[$idx]);
        }
        else{
            push(@rr,WILDCARD) unless WILDCARD == $rr[-1];
        }
        $idx++ if $r->[0] ne '+';
    }
    return \@rr;
}



1;

__END__