Using Parse::Lex, is there a way to return tokens only in certain states/conditions - perl

Question

Assuming that i need to tokenize and parse only multiline comments, how will i do that using Parse::Lex. When using flex-bison, the default action for any pattern in the rules section of the lex file used to be 'skip'.
%%
.* ;
%%
How to do this here ?
[EDIT] Well, i tried that, i'm still missing something - here is my code - and result. Where have i gone wrong ??
my simplified lex file:
use Parse::Lex;
use Regexp::Common;
use YParser;
my $lexer;
my #token = (
qw|esp:TA abcdefgh|,
qw(esp:REST .|\n),
);
Parse::Lex->trace;
Parse::Lex->exclusive('esp');
$lexer = Parse::Lex->new(#token);
$lexer->from(\*STDIN);
$lexer->skip(qr! [ \t]+ | $RE{balanced}{-begin=>'/*'}{-end=>'*/'} !xms);
$lexer->start('esp');
my $j = YParser->new();
$j->YYParse(yylex => \&lex);
sub lex {
my $token = $lexer->next;
return ('', undef) if $lexer->eoi;
if ($token->name eq 'TA' || $token->name eq 'REST') {
return ($token->name, {LINENO => $lexer->line, TEXT => $token->text});
}
}
my simplified grammar file
% token TA REST
%%
Program: Element
| Program Element
;
Element: TA
| REST
;
%%
Input file:
abcdefgh
/*sdf*/
Result:
perl lexfile.pl < inputfile
Trace is ON in class Parse::Lex
Can't call method "name" on an undefined value at qnlex.pl line 26, <STDIN> line 1.

Answer 1

Use the skip setting, shown here using Regexp::Common to help construct a regexp matching balanced pairs of comment delimiters. I've assumed /* */ as the comment delimiters, but they could be anything.
$lexer->skip(qr! [ \t]+ | $RE{balanced}{-begin=>'/*'}{-end=>'*/'} !xms);
The [ \t]+ alternative is left in place since that's the default.

Answer 2

Well, i figured this out :) Very simple - all i have to do is make the lex get the next token when encountering tokens i want to skip. Below is code to skip passing the token 'REST' to the parser.
sub lex {
my $token;
NEXTTOKEN:
$token = $lexer->next;
return ('', undef) if $lexer->eoi;
if ($token->name eq 'TA') {
return ($token->name, {LINENO => $lexer->line, TEXT => $token->text});
}
elsif ($token->name eq 'REST') {
goto NEXTTOKEN;
}
}