Regex Error (but okay in Regex101)

[Bobbins]

Hello,

Text String;

"The very Blue Sea is always blue unless its orange when its not BLUE sea"

The idea is to split on every "blue" regardless of case to give:

The very

Blue Sea is always

blue unless its orange when its not

BLUE sea

This works in Reg101 but not in Regex as to parse it gives the error: "Error: Nothing to parse. Enter a complete expression."

Code is:
(?i)\s+(?=\bblue\b)

Thank you

[Bobbins]

The example represents a real life scenario for me where I need the case of the lettering to be kept. If i didn't, then your example would have been perfect. Your solution is valid for someone whom case will not matter and I thank you for noting how it could be done this way. If i can select multiple solutions i will do!

[PhilipMannering]

You can also tokenize on this,

(.+?)\s+(?=blue|$)

No need to worry about the (?i) - you can just have the case insensitive box ticked.

[Bobbins]

Interesting @PhilipMannering 

Running this it picks up the first two blues but the all in caps BLUE it fails

[PhilipMannering · Accepted solution]

So it does..

This looks about right,

[Bobbins]

Wow, thanks for that. Question over the regex part, whats the pipe for in "(?=blue|$)"

[PhilipMannering · Accepted solution]

The pipe | means "or". And $ means end of line.

So in this case we're saying that we want to capture text up until a "blue" or "end of the line".

Thinking about it, you'll want to use (?=\bblue\b|$) to split on blue as a word...if you didn't want to split on, say, "bluetooth".

[Bobbins]

Perfect, thank you @PhilipMannering