clojure equivalent for ruby's gsub

Question

How do i do this in clojure

"text".gsub(/(\d)([ap]m|oclock)\b/, '\1 \2')

Answer 1

That would be replace in the clojure.string namespace. You can find it here.

Use it like so:

(ns rep
  (:use [clojure.string :only (replace)]))
(replace "this is a testing string testing testing one two three" ;; string
         "testing" ;; match
         "Mort") ;; replacement

replace is awesome because the match and replacement can also be string/string or char/char, or you could even do regex pattern/function of the match or string.

Answer 2

You can use Java's replaceAll method. The call would look like:

(.replaceAll "text" "(\\d)([ap]m|oclock)\\b" "$1 $2")

Note that this will return a new string (like gsub (without the bang) would in ruby). There is no equivalent for gsub! in clojure as java/clojure string are immutable.

Answer 3

To add to Isaac's answer, this is how you would use clojure.string/replace in this particular occasion:

user> (str/replace "9oclock"
                   #"(\d)([ap]m|oclock)\b"
                   (fn [[_ a b]] (str a " " b)))
                      ; ^- note the destructuring of the match result
                  ; ^- using an fn to produce the replacement 
"9 oclock"

To add to sepp2k's answer, this is how you can take advantage of Clojure's regex literals while using the "$1 $2"gimmick (arguably simpler than a separatefn` in this case):

user> (.replaceAll (re-matcher #"(\d)([ap]m|oclock)\b" "9oclock")
                             ; ^- note the prettier regex
                   "$1 $2")
"9 oclock"