On page 72, the book Effective Perl Programming shows some code to remove C-style comments from a string. I've reproduced the code below.
local $_;
$_ = "
This_Is_Code = 0; /* This is a comment */
/*
* Can it handle a mult-line comment, i.e.
* one that goes on for more that one
* line? Yes, it can.
*/
This_Is_Code++;
";
for (split m!("(:?\\\W|.)*?"|/\*|\*/)!) {
if ($in_comment) {
$in_comment = 0 if $_ eq "*/"
} else {
if ( $_ eq "/*" ) {
$in_comment = 1;
print " ";
} else {
print;
}
}
}
I have a question about the regular expression that's used in the call to split(). The expression (:?\\\W|.) seems to say match either a non-word character, or any character. Why have both patterns in the alternation when the dot includes non-word characters?
Thanks,
Carl-Joseph