natural-compare

A natural-sort compatator for strings in Clojure/Script. Sorts embedded digits as integers, so strings like ["v12" "v2"] will sort 'naturally' as you would expect:

(def v ["v12" "v2"])

(sort v)
;;user=> ("v12" "v2")   ;; lexical sort

(sort natural-compare v)
;;user=> ("v2" "v12")   ;; 'natural' sort

Install

deps.edn

wevre/natural-compare {:mvn/version "0.0.8"}

project.clj

[wevre/natural-compare "0.0.8"]

How to use

(require '[wevre/natural-compare :refer [natural-compare]])

(def ss ["t3" "t1" "t10" "t12" "t2" "t27"])

(sort natural-compare ss)

;;=> ("t1" "t2" "t3" "t10" "t12" "t27")

How it works

natural-compare operates on strings. Each is split into a sequence of alternating text and integer elements and then the two sequences are compared element by element. The trick is to make sure that when splitting the string, the first element is always text, the elements always alternate between text and integer, and the last element is an integer. The sequence is padded as necessary with values "" and -1 (which always sort lower than 'legit' values) to make sure shorter strings sort first.

See test cases for more examples.

License

Copyright © Mike Weaver

Licensed under the terms of Ecplise Public License 2.0, see license.txt.