performance improvements needed

[boxxxie]

i am using this to convert camel case json to clojure kabab case keywords...
i have found that this conversion is extremely slow!

please offer memoized versions in this lib. :)

[qerub]

You can easily memoize the functions yourself with clojure.core.memoize so I see no point in offering it built-in.

In regard to performance, I'd happily accept concrete advice or patches unless they sacrifice code readability.

[qerub]

By the way, com.google.common.base.CaseFormat is a more performant alternative.

[qerub]

I added some notes about memoization to the README: https://github.com/qerub/camel-snake-kebab/tree/master#with-memoization