mogrify
The mogrify gem is a set of non-destructive transformers for enumerable objects. The tests are the best place to look for a feel of what the methods do.
symogrify
Instance method on Hash, returns the same hash with all string keys converted to symbols (even keys in nested hashes).
hashmogrify
Monkey patch for enumerable, takes a block and returns a hash where the key and value are the result of applying the block to the enumerable.