ceil

Returns the smallest double greater than or equal to a, and equal to a mathematical integer. If a is ##NaN or ##Inf or ##-Inf or already equal to an integer => a Note that if a is `nil` then an exception will be thrown. This matches Clojure, rather than js/Math.ceil See: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/ceil