Immutable and interned! (This may or may not be an issue, but it still offended me somewhat, since you're getting all of the compile-time cost at runtime, comb

Immutable and interned! (This may or may not be an issue, but it still offended me somewhat, since you're getting all of the compile-time cost at runtime, combined with none of the expressiveness. Not a tradeoff that impresses me, personally, even if the speed is fine - but it takes all sorts.)