Problem with P::RD grammar

TStanley has asked for the wisdom of the Perl Monks concerning the following question:

I am working on a new grammar for my Config::Yacp module so that it can handle comments inside the configuration file. My test script is below:

#!/opt/perl5/bin/perl -w
use strict;
use Parse::RecDescent;
use vars qw ($grammar);

$::RD_AUTOACTION=q{print"$item[0]: @item[1..$#item]\n"; 1};

$grammar = q(
      file: section(s)
      section: header assign(s?)
      header: '[' /\w+/ ']'
      assign: /\w+/ '=' /\w+/ | /\w+/ '=' /\w+/ '' /\s+[\;#]/ /\w+$/
      );
my $parser= Parse::RecDescent->new($grammar);

my $text;

{
 $/=undef;
 $text=<DATA>;
}

my $tree=$parser->file($text);

__DATA__
[Section1]
key1 = value1    #Comment
key2 = value2   ;Comment
key3 = value3

[Section2]
key4 = value4
key5 = value5
[download]

The output from this is:

header: [ Section1 ]
assign: key1 = value1
section: 1 ARRAY(0x401da6cc)
file: ARRAY(0x401da708)
[download]

By printing out $#item in the $::RD_AUTOACTION, I was able to see that it was totally ignoring anything past the value.
Can someone give me a pointer in the right direction?

TStanley
--------

Comment on Problem with P::RD grammar Select or Download Code

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Re: Problem with P::RD grammar by artist (Parson) on May 23, 2003 at 19:00 UTC
If you set $::RD_TRACE, it would tell you where it stopped working for the first time, by not matching the terminals or rule or subrules. The following code works as per what you want. `$grammar = q( file: section(s) section: header assign(s?) header: '[' /\w+/ ']' assign: pair comment(?) pair: /\w+/ '=' /\w+/ comment: /[\;\#]/ /\w+/ };` [download] It gives you the output like: `header: [ Section1 ] pair: key1 = value1 comment: # Comment assign: 1 ARRAY(0x1d5e758) pair: key2 = value2 comment: ; Comment assign: 1 ARRAY(0x2014078) pair: key3 = value3 assign: 1 ARRAY(0x1d5e818) section: 1 ARRAY(0x1d5e74c) header: [ Section2 ] pair: key4 = value4 assign: 1 ARRAY(0x20140cc) pair: key5 = value5 assign: 1 ARRAY(0x1d5e830) section: 1 ARRAY(0x2014090) file: ARRAY(0x2014084)` [download] The removal of the '$' sign at the end of the 'assign' terms does the trick. I also seperated the comments from the key value pair. artist	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: Problem with P::RD grammar
by artist (Parson) on May 23, 2003 at 19:00 UTC

The following code works as per what you want.

$grammar = q(
       file: section(s) 
       section: header assign(s?)
       header: '[' /\w+/ ']'
       assign: pair comment(?)
       pair:   /\w+/ '=' /\w+/
       comment: /[\;\#]/ /\w+/
};
[download]

header: [ Section1 ]
pair: key1 = value1
comment: # Comment
assign: 1 ARRAY(0x1d5e758)
pair: key2 = value2
comment: ; Comment
assign: 1 ARRAY(0x2014078)
pair: key3 = value3
assign: 1 ARRAY(0x1d5e818)
section: 1 ARRAY(0x1d5e74c)
header: [ Section2 ]
pair: key4 = value4
assign: 1 ARRAY(0x20140cc)
pair: key5 = value5
assign: 1 ARRAY(0x1d5e830)
section: 1 ARRAY(0x2014090)
file: ARRAY(0x2014084)
[download]

artist

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