Fix regression introduced in fafe8f0f53bf91fc41f016b5c2af41ca712783f7.
Counting the number of hyphens in a string cannot be done in a single
expression, thus split this and introduce another local variable.
Fixes#227.
This is the (partially) documented public API for Homebrew.
The main class you should look at is the {Formula} class (and classes linked from there). That's the class that's used to create Homebrew formulae (i.e. package descriptions). Assume anything else you stumble upon is private.