CODEWITHSUNDEEP
regex
Makani McDougall
Makani McDougall

Reputation: 23

regular expression for excluding between

I have the following regular expression:

first.*(?<!.*([;,\.]|and).*)second

I would like it to match the following:

first some word second

But not match the following:

first . some word second

first ; some word second

It is working but it is also excluding the following:

blah ; first some word second

I only want it to exclude matches if the negative look ahead falls in between the two words. It should not look behind the first word.

Upvotes: 0

Views: 51

Answers (2)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626754

First, you are not using a lookahead, in your pattern, you are using a lookbehind with an unknown width pattern inside. You want to match a string between a and b excluding c, and this is a common scenario for a tempered greedy token:

first(?:(?!and)[^;,.])*second

See the regex demo. Use word boundaries to match whole words: \bfirst\b(?:(?!\band\b)[^;,.])*\bsecond\b.

Details

  • first - a literal substring
  • (?:(?!and)[^;,.])* - zero or more chars other than ;, , and . that do not start an and char sequence
  • second - a literal substring.

Upvotes: 0

blhsing
blhsing

Reputation: 106533

You can simply use:

first\b[^.;]*\bsecond

Upvotes: 1

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