Ah, good thought. So, by doing this the "compiled" eval is kept in memory and this eval, if called again is much more efficient? Oh, wait! The eval is only done once per degree, the compiled translation subroutine is assigned to the %pwdrots hash, then used as needed.

Excellent! This makes a file of x strings all using the same transformation a lot more efficient.

In reality, I'm hoping for a slightly more philisophical discussion of the pro's and con's of the various methods available. Holding some hope for a magical "use this instead of an eval'ed tr//".