File Coverage

blib/lib/PerlX/Let.pm

Criterion	Covered	Total	%
statement	32	32	100.0
branch	11	12	91.6
condition	5	6	83.3
subroutine	8	8	100.0
pod			n/a
total	56	58	96.5

package PerlX::Let;

# ABSTRACT: Syntactic sugar for lexical state constants

use v5.12;
use warnings;

use Const::Fast ();
use Keyword::Simple 0.04;
use Text::Balanced ();

our $VERSION = 'v0.3.0';


sub import {
    Keyword::Simple::define 'let', \&_rewrite_let;
}

sub unimport {
    Keyword::Simple::undefine 'let';
}

sub _rewrite_let {
    my ($ref) = @_;

    my $let = "";

    my ( $name, $val );

    ( $name, $$ref ) = Text::Balanced::extract_variable($$ref);
    die "A variable name is required for let" unless defined $name;
    $$ref =~ s/^\s*\=>?\s*// or die "An assignment is required for let";
    ( $val, $$ref ) = Text::Balanced::extract_quotelike($$ref);
    ( $val, $$ref ) = Text::Balanced::extract_bracketed( $$ref, '({[' )
        unless defined $val;

    unless ( defined $val ) {
        ($val) = $$ref =~ /^(\S+)/;
        $$ref =~ s/^\S+//;
    }

    die "A value is required for let" unless defined $val;

    if ($val !~ /[\$\@\%\&]/ && ($] >= 5.028 || substr($name, 0, 1) eq '$')) {

        # We can't use Const::Fast on state variables, so we use this workaround.

        $let .= "use feature 'state'; state $name = $val; unless (state \$__perlx_let_state_is_set = 0) { Const::Fast::_make_readonly(\\$name); \$__perlx_let_state_is_set = 1; };";

    }
    else {

        $let .= "Const::Fast::const my $name => $val; ";
    }

    substr( $$ref, 0, 0 ) = $let;

}



1;

__END__