How to Modify Only Non-Quoted Words?

[ventolin]

Hi Monks,

I'm a bit lost on the best solution - what's the best way to prefix every word in a string with the letter A except any words within quotes?

Thanks!

[ikegami]

$_ = q{
xxx "xxxxx xxx xxxx" 'xxxx xx xx' xxxx xxxx "xxxxx " "xxx" xxx
};

s/
   \G
   ( # $1
      (?:
         (?:"(?:[^"\\]|\\.)*")  # Skip double-quoted phrases.
         |
         (?:'(?:[^'\\]|\\.)*')  # Skip single-quoted phrases.
         |
         \s                     # Skip whitespace.
      )*
   )
   ( # $2
      [^\s"']+                  # Something to prefix.
   )
/$1A$2/gsx;

print;


__END__
output:
======
Axxx "xxxxx xxx xxxx" 'xxxx xx xx' Axxxx Axxxx "xxxxx " "xxx" Axxx

[ventolin]

Works great! Thanks!

[ccn]

s { ([^"']*)?   # non quoted part
   ("[^"]*")?   # doublequoted
   ('[^']*')?   # singlequoted 
  }
  {
    my($x, $y, $z) = map {defined() ? $_ : ''} $1, $2, $3;
    $x =~ s/(?<!\S)(?=\S)/A/g;
    $x . $y . $z
  }xge;

[Your Mother]

Don't know if it's relevant to the problem but both your and ikegami's solutions fail when contractions enter into the "word" list.

[ikegami]

If you want to escape quotes oustide of quoted strings, change

   ( # $2
      [^\s"']+                  # Something to prefix.
   )

to

   ( # $2
      (?:[^\s"'\\]|\\.)+        # Something to prefix. 
   )

[Your Mother]

Don't get me wrong, I enjoyed reading both solutions. They break down on a string like: She said, 'I've known you can't since yesterday.' Not that it is necessarily relevant to OP's real problem.