Regex to insert space in vim

Question

I am a regex supernoob (just reading my first articles about them), and at the same time working towards stronger use of vim. I would like to use a regex to search for all inst

Answer 1

You want to use a zero-width negative lookahead assertion, which is a fancy way of saying look for a character that's not a space, but don't include it in the match:

:%s/: \@!/: /g

The \@! is the negative lookahead.