Replace whole words in string

Question

replace-string has the DELIMITED parameter, which can be used to replace only whole words. replace-in-string does not have such a parameter. Is there an easy work-around besides creating a temporary buffer and using replace-string?

Answer 1

I don't know the function replace-in-string, but assuming it uses emacs regex (or using replace-regexp-in-string) you should be able to use word boundaries. You could match foo by using \bfoo\b (or in a string "\\bfoo\\b").

For example, evaluating (replace-regexp-in-string "\\bfoo\\b" "bar" "afoo foob foo moo") would result in the string "afoo foob bar moo".

See here for a detailed description.

Answer 2

Based on the answer of @theldoria, here is the function:

(defun replace-in-string-whole-words(what with in)
  "Like 'replace-in-string, but replaces whole words."
  (replace-regexp-in-string (concat "\\b" what "\\b")  with in))