Question

The “not followed by” operator is as follows: ( per quick reference at http://regexpal.com/ )

?!exprssion

Can I chain these together like this?

?!(?!exprssion)

Why do I ask you ask?

because I need to split() on

|

or

| not follwed by |*

but

| followed by |** is O.K.

See how that is complicated?

Broken Try

.split( /\|\*\*|\|(?!\*)/ );

This does not work because it splits on

|**

and I need my split on

|

Answer 1

Split on this:

\|(?!\*)|\|\*\*

This says: either a pipe followed by something not a star (which we will not use to split on), or a pipe followed by 2 stars (use the whole thing to split). I’m not certain from your wording if that’s what you’re looking for. If you mean “split on pipe, unless it’s followed by a single star, but split on a pipe following by 2 stars” then use this:

\|(?!\*[^*])

Demo: http://codepad.org/Gt0xNQNO