package Regexp::Simple;

use overload;
use Parse::RecDescent;

local $/;
my $translate = Parse::RecDescent->new(<DATA>);

sub import {
        overload::constant qr => sub {
                return $translate->pattern($_[0]);
        }
}

1;

__DATA__
{ sub wrap { "(?:$_[0])".($_[1]||"") } }

pattern: element(s)         { join '', @{$item{element}} }

element: 'start_of_line'    { '^' }
       | 'whitespace'       { '\\s' }
       | 'digit'            { '\\d' }
       | 'non_digit'        { '\\D' }
       | 'literal' subpat   { wrap $item{subpat} }
       | 'optional' subpat  { wrap $item{subpat}, '?' }
       | 'many' subpat      { wrap $item{subpat}, '+' }
       | 'any' subpatlist   { wrap join "|", @{$item{subpatlist}} }
       | 'remember' subpat  { "($item{subpat})" }
       | <perl_quotelike>   { quotemeta $item[1][2] }

       # etc. as necessary

subpat: '(' pattern ')'     { $item[2] }

subpatlist: '(' pattern(s /,/) ')'
                            { $item[2] }


##</code><code>##

use Regexp::Simple;

my $re = qr{
        start_of_line
        literal("1998/10/08")
        optional( whitespace )
        literal("[")
        remember( many( any( ":", digit ) ) )
        non_digit
};

if ('1998/10/08 [11:10]' =~ m/$re/) {
   print "Found a match at time $1!\n";
}