Clojure for the Brave and True

It is better to have 100 functions operate on one data structure than 10 functions on 10 data structures.
—Alan Perlis

let creates a new scope in which the name x is bound to the value 1. I think of scope as

You can also pass a rest parameter with %&:

(#(identity %&) 1 "blarg" :yip); => (1 "blarg" :yip)