I am trying to match anything that isn't the previous match with regex.

I have the following regex:

(?<return>return)|(?<other>(?![ \n]).*?(?=(?:[\s\n]|$)))

If I use it on the following string, I get one match for the return group

return

But on the following string I get the other group:

 return

(notice the space before the return).

The regex for other shouldn't match any spaces (or new lines) however (due to the (?![ \n]).

So, for example let's say I have the following string: return abc 123. Then I'd like to have 3 matches using the above regex: one in the return group which contains "return", and two in the other group containing "abc" and "123"

I can't seem to figure out why this is happening. Does anyone have an explanation for this? And how can I fix this?

CodePudding user response：

You might use

(?<return>return)|(?<other>\S )

It matches

• (?<return>return) - Group "return": a return substring
• | - or
• (?<other>\S ) - Group "other": one or more non-whitespace chars.

If the return can appear inside a non-whitespace chunk, you might want to exclude return from the second part: (?<return>return)|(?<other>(?:(?!return)\S) ). See demo.

If there must be a whitespace or start of string on the left, and a whitespace or end of string on the right, you may add whitespace boundaries:

(?<!\S)(?:(?<return>return)|(?<other>\S ))(?!\S)

See this regex demo.