Perl program for parsing a Ruby file

Hai anyone please prov开发者_开发问答ide me a code or say the perl module for parsing a ruby file. Like it has to count the number of lines having comments. Number of lines having source code. Extract the source code and extract the comment lines. Thanks in Advance

---

You could simply process the ruby source file and count any line that starts with \s*# or is only whitespace as a comment and all else as code...

---

You could write a grammar for Regexp::Grammars, which will in turn parse the file for you. The module is very well documented.

I hope the following script will help you understand the idea behind parsing:

Parser

#!/usr/bin/env perl

use strict;
use warnings;

use Regexp::Grammars;

my $parser = qr{
    <File>

    <rule: File>
        (
              (?:
                    \n
                  | <[Comment]>
              )
            | <[Comment]>
            | <[Source]>
        )+

        <rule: Comment>
              \# <InlineComment>
            | ^=begin
             <MultilineComment> \n
             ^=end

            <rule: InlineComment>
                [^\n]+

            <rule: MultilineComment>
                .*

    <rule: Source>
        [^\n]+
}xms;

my $text = do { local $/; <DATA> };

if ( $text =~ $parser ) {
    my @source;
    my @comments;

    if ( exists $/{'File'}->{'Source'} ) {
        @source = @{ $/{'File'}->{'Source'} };
    }
    if ( exists $/{'File'}->{'Comment'} ) {
        @comments = @{ $/{'File'}->{'Comment'} };
    }

    my $line = 1;
    print '__SOURCE__ [', scalar @source, "]\n";

    for (@source) {
        print "$line: $_\n";
        $line++;
    }

    print "\n\n";

    $line = 1;
    print '__COMMENTS__ [', scalar @comments, "]\n";

    for my $comment (@comments) {
        print "$line: ";

        if ( exists $comment->{'InlineComment'} ) {
            print $comment->{'InlineComment'};
        }
        elsif ( exists $comment->{'MultilineComment'} ) {
            print $comment->{'MultilineComment'};
        }

        print "\n";
        $line++;
    }
}
else {
}

__DATA__
=begin
The following code snippet was copied from:
http://www.ruby-lang.org/en/documentation/quickstart/4/
=end
# Say hi to everybody
def say_hi
  if @names.nil?
    puts "..."
  elsif @names.respond_to?("each")
    # @names is a list of some kind, iterate!
    @names.each do |name|
      puts "Hello #{name}!"
    end
  else
    puts "Hello #{@names}!"
  end
end

Output

__SOURCE__ [11]
1: def say_hi
2: if @names.nil?
3: puts "..."
4: elsif @names.respond_to?("each")
5: @names.each do |name|
6: puts "Hello #{name}!"
7: end
8: else
9: puts "Hello #{@names}!"
10: end
11: end


__COMMENTS__ [3]
1: The following code snippet was copied from:
http://www.ruby-lang.org/en/documentation/quickstart/4/
2: Say hi to everybody
3: @names is a list of some kind, iterate!