Just to clear up MeowChow's answer, the => acts like a comma AND tries to quote the word to its left. If you confuse the parser into not knowing that it is reading a word, it doesn't know what to quote and it complains and dies. Basically if your words are going to have characters other than a-zA-Z0-9_- in them, go ahead and quote it manually and save yourself and the parser some worry.

--
$you = new YOU;
honk() if $you->love(perl)