File Coverage

blib/lib/Text/Wrap/Smart.pm

Criterion	Covered	Total	%
statement	73	73	100.0
branch	14	16	87.5
condition	9	9	100.0
subroutine	13	13	100.0
pod	2	2	100.0
total	111	113	98.2

package Text::Wrap::Smart;

use strict;
use warnings;
use base qw(Exporter);
use boolean qw(true);

use Carp qw(croak);
use Math::BigFloat ();
use Params::Validate ':all';

our ($VERSION, @EXPORT_OK, %EXPORT_TAGS);
my @subs;

$VERSION = '0.9';
@subs = qw(exact_wrap fuzzy_wrap);
@EXPORT_OK = @subs;
%EXPORT_TAGS = ('all' => [ @subs ]);

use constant WRAP_AT_DEFAULT => 160;

validation_options(
    on_fail => sub
{
    my ($error) = @_;
    chomp $error;
    croak $error;
},
    stack_skip => 2,
);

my $pre_process = sub
{
    local $_ = ${$_[0]};

    s/^\s+//;
    s/\s+$//;
    s/\s+/ /g;

    ${$_[0]} = $_;
};

my $calc_average = sub
{
    my ($text, $wrap_at) = @_;

    my $length = length $text;

    my $i = int $length / $wrap_at;
       $i++ if  $length % $wrap_at != 0;

    my $x = Math::BigFloat->new($length / $i);
    my $average = $x->bceil;

    return $average;
};

sub exact_wrap
{
    _validate(@_);
    my ($text, $wrap_at) = @_;

    $pre_process->(\$text);
    return () unless length $text;

    $wrap_at ||= WRAP_AT_DEFAULT;
    my $average = $calc_average->($text, $wrap_at);

    return _exact_wrap($text, $average);
}

sub fuzzy_wrap
{
    _validate(@_);
    my ($text, $wrap_at) = @_;

    $pre_process->(\$text);
    return () unless length $text;

    $wrap_at ||= WRAP_AT_DEFAULT;
    my $average = $calc_average->($text, $wrap_at);

    return _fuzzy_wrap($text, $average);
}

sub _exact_wrap
{
    my ($text, $average) = @_;

    my @chunks;

    for (my $offset = 0; $offset < length $text; $offset += $average) {
        push @chunks, substr($text, $offset, $average);
    }

    return @chunks;
}

sub _fuzzy_wrap
{
    my ($text, $average) = @_;

      my @spaces;
    push @spaces, pos $text while $text =~ /(?= )/g;

    my $pos          = $average;
    my $start_offset = 0;
    my $skip_space   = 1;

    my @offsets;

    while (true) {
        my $begin = @offsets ? ($offsets[-1] + $skip_space) : $start_offset;

        my $index = index($text, ' ', ($begin == $start_offset ? $start_offset : $begin - $skip_space) + $average);
        last if $index == -1;

        my @spaces_prev = grep $_ <= $pos, @spaces;

        my $space_prev = $spaces_prev[-1] || undef;
        my $space_next = $index;

        splice(@spaces, 0, scalar @spaces_prev);
        @spaces = grep $_ != $space_next, @spaces;

        if (defined $space_prev && substr($text, $begin, $space_prev - $begin) =~ / /) {
            push @offsets, $space_prev;
        }
        else {
            push @offsets, $space_next;
        }
        $pos = $offsets[-1] + $skip_space + $average;
    }

    my @chunks;

    my $begin = $start_offset;
    foreach my $offset (@offsets) {
        my $range = $offset - $begin;
        if ($text =~ /\G(.{$range}) (?=[^ ])/g) {
            push @chunks, $1;
        }
        $begin = $offset + $skip_space;
    }
    push @chunks, $1 if $text =~ /\G(.+)$/;

    return @chunks;
}

sub _validate
{
    validate_pos(@_,
        { type => SCALAR },
        { type => SCALAR, optional => true, regex => qr/^\d+$/ },
    );
}

1;
__END__