Well, it breaks because the /e modifier means, evaluate the
right-hand side of this substitution as Perl code. And that's not
valid Perl code. But you may have already known that.
Did you try running it through B::Deparse? This is what you get:
$words = 'This%is%Devious';
$words =~ s/%/do { () }/eg;
$words =~ s/ /do { %} }\n/eg;
print "$words\n";
Of course, this isn't valid code either, nor is the original with the
ending curly brace. :) But apparently you're tricking the
parser into recognizing it as valid. Very odd...
Some wonderful opportunities for obfuscation may lie down
this path, it seems. :)
