File Coverage

blib/lib/Perl6/Placeholders.pm

Criterion	Covered	Total	%
statement	6	6	100.0
branch			n/a
condition			n/a
subroutine	2	2	100.0
pod			n/a
total	8	8	100.0

package Perl6::Placeholders;

use Filter::Simple;

our $VERSION = '0.07';

my %giftwrap = (
        'sort' => sub {"{$_[0]\->(\$a,\$b)}"},
        'grep' => sub {"{$_[0]\->(\$_)}"},
        'map'  => sub {"{$_[0]\->(\$_)}"},
        'sub'  => sub {$_[0]},
        ''     => sub {$_[0]},
);

use re 'eval';
our $code        = qr{ (?: [^{}]+ | \{ (??{ $code }) \} )* }x;
our $placeholder = qr{ (?: $code (?: (??{ $carvar }) $code ) )+ }x;
our $carvar      = qr{ (?: \$\w+ (?:
                        (?:->)?  (?:\[$placeholder\]|\{$placeholder\}) )+
                       | \$\^\w+
                       )
                     }x;

FILTER_ONLY
        executable => sub {
                        s<(sub|sort|map|grep)?\s*(?=.*\$\^\w)\{($placeholder)\}> {
                                my ($context,$code) = ($1||"",$2);
                                my %vars;
                                @vars{$code =~ m/(\$\^\w+)/g} = ();
                                my $vars = join ',', sort keys %vars;
                                my $decl = qq{my($vars)=\@_;};
                                $decl = "" if $code =~ /\Q$decl/;
                                $code = qq{ sub {$decl $code } };
                                $code =~ s/\$\^(\w+)/\$$1/g;
                                "$context ". $giftwrap{$context}($code);
                        }ge;
                },

__END__