#!/usr/bin/perl --
use strict;
use warnings;
use Data::Dump qw/ dd /;
use Marpa::R2;

my $hamlInput = q{-# haml comment
%p a paragraph
%p
  %span foo inside span inside p
};


my $syntax = <<'__SYNTAX__';
:default ::= action => [values]

:start ::= haml
haml        ::= comments | oneliners

oneliners    ::= oneliner+

comments    ::= comment+

comment     ::= <hash style comment>

# oneliner   ::= <terminated oneliner> | <unterminated oneliner>
oneliner   ::= <terminated oneliner>
oneliner   ::= <unterminated oneliner>

<terminated oneliner>               ~ '%' tagname <oneline body> <vertical space char>
<unterminated oneliner>             ~ '%' tagname <oneline body>
<oneline body>                      ~ <hash comment char>+

tagname ~ [a-zA-Z]+

# Hash comment handling copied from Marpa::R2's metag.bnf.

<hash style comment>                ~ <terminated hash comment>
                                                                                | <unterminated final hash comment>

<terminated hash comment>           ~ '-#' <hash comment body> <vertical space char>

<unterminated final hash comment>   ~ '-#' <hash comment body>

<hash comment body>                 ~ <hash comment char>*

<vertical space char>               ~ [\x{0A}\x{0B}\x{0C}\x{0D}\x{2028}\x{2029}]

<hash comment char>                 ~ [^\x{0A}\x{0B}\x{0C}\x{0D}\x{2028}\x{2029}]

__SYNTAX__

my $grammar = Marpa::R2::Scanless::G->new({source => \$syntax});
my $recce   = Marpa::R2::Scanless::R->new( {
        grammar => $grammar ,
        trace_values => 1,
        trace_terminals => 1,
    } );
eval {
    dd( $recce->read( \$hamlInput, ) );
#~     dd( $recce->read( \$hamlInput, 0,16 ) );
    1;
} or warn $@;
my $value_ref = $recce->value();
dd( $value_ref );
#~ dd( $recce, $grammar );

__END__
Setting trace_terminals option
Setting trace_values option
Accepted lexeme L1c1-16 e1: <hash style comment>; value="-# haml comment
"
Rejected lexeme L2c1-15: <terminated oneliner>; value="%p a paragraph
"
Error in SLIF parse: No lexemes accepted at line 2, column 1
  Rejected lexeme #0: <terminated oneliner>; value="%p a paragraph
"; length = 15
* String before error: -# haml comment\n
* The error was at line 2, column 1, and at character 0x0025 '%', ...
* here: %p a paragraph\n%p\n  %span foo inside span inside
Marpa::R2 exception at - line 60.
\[[["-# haml comment\n"]]]