Hi, If there was no x in the comment, the second test would still fail because there is no ' x' to match (note the blank space before the x). But I agree with you that I am trying to do too much with regular expression. I believe I can do the following: 
    my $c = qr/(?>\s|--[^\n]*(?:\n|\z))/; # one whitespace or one comm
+ent

    # later on, when parsing...

    pos($str) = 0;

    if ($str =~ m/a/gc)
      { print "found a\n" } else { print "missing a\n" }

    $str =~ m/$c*/gc; # skip any comments, whitespaces

    if ($str =~ m/x/gc)
      { print "found x\n" } else { print "missing x\n" }

[download]
I am not sure if I need set pos($str) to 0 at the beginning. And I am not sure if I need to use \G when parsing.

But again, thanks for your ideas!

In reply to Re^2: How do I avoid regex engine bumping along inside an atomic pattern? by zemane
in thread How do I avoid regex engine bumping along inside an atomic pattern? by zemane

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