RE: <skip: over comments> and misleading <error> messages

.....

> The problem is, (as far as I understand) that the <skip> must be
> bound to a rule, and when the rule isn't matched, then the already
> skipped text is stuffed back to the $text stream from where the
> <error> directive is generating the message "but found ....".
> 
> If Damian had spent a Package Variable:
> 
> $RD_SKIP

Well, there is such a variable, but its not called $::RD_SKIP its called 

$Parse::RecDescent::skip

(I assume that this variable is defined in the Parse::RecDescent namespace
because it has a default value)

Note that it appears this value is a string, and not a regex (i could be
wrong, I havent checked the source code)

So if you rewrite your example to be (with a couple of extra comments for
testing)

#!/usr/bin/perl -w
use Parse::RecDescent;
# Ignore continuous whitespace or # and everything after it.
$Parse::RecDescent::skip=qr/
                            (
                             ^\s+   # ignore continuous whitespace
                            |       # or 
                             \#.*$  # Comment to the end of the line (the \
is mandatory)
                            )+      # One or many times.
                          /x;       # xtended regex syntax, ignore
whitespace and comments in regex
my $grammar =<<'EOGRAMMAR';
	file 	: int(s) /\z/
			| <error>

	int		: /[+-]?\d+/
			| <error>
EOGRAMMAR

my $parser = Parse::RecDescent->new($grammar);

my $text = <<'EOTEXT';
	# comment
	123 #comment
	# comment
	.123 #Comment
EOTEXT

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

__END__

The I get the following result


       ERROR (line 1): Invalid int: Was expecting /[+-]?\\d+/

       ERROR (line 1): Invalid file: Was expecting int


Which is what I believe you wanted.

Incidentally the regex you posted qr{(\s*(#.*\n)*)*} scares the *sh*t* out
of me.  (The )*)* is a construct that may not be wrong in this case but
often _is_ very wrong, so when I see it my spidey sense goes crazy, and I
replace it.  (Not everything a programmer does is logical...)

I rewrote it as /(^\s+|#.*)+$/ which to me is much safer and easier to
understand too.

Yves