The problem is that the code is potentially ambigous.

There are two ways to parse it: 

s{...}{
 # much stuff here
}x

[download]

The other, but less obvious, ist this: 

s{...}{ 
# some characters 
{}{
# more characters...
}
# no terminator

[download]

When perl tries to parses the regex it doesn't know if there is going to come an /x modifier, so the braces have to be balanced - even in comments.

That's one of the reasons Perl 6 puts the modifiers at the start of the regexes.

Perl 6 in German

In reply to Re: Commented braces in Code by moritz
in thread Commented braces in Code by sanPerl

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