hash-combine

(hash-combine x y)

clojure.core/hash-combine: boost's combination of the int x with y's Java hashCode (Util.hash: 0 for nil, a collection's List, Map or Set hash, a keyword's Keyword.hashCode), x xor (hashCode + 0x9e3779b9 + (x << 6) + (x >> 2)) in 32 bits. x is cast like an int parameter: a double or a ratio truncates, a value past the int range is the oracle's ArithmeticException, and a character or nil is refused.