Regex lookbehind - excluding words from searches

Question

I need to search my corpus for words such as game or shame but I would like to specify the search to exclude three strings a game/a shame or , A game/A shame and a/an/A/An WORD game or a/an/A/An WORD shame , where WORD is a modifier, e.g., a great game or a great shame.

If someone could help me out, that would be great, thanks!

In my corpus, the optional WORD between the indefinite article a/an and game or a/an and shame is most commonly great and real. So even excluding these two, would already help me a lot.

The lookbehind below works perfectly to exclude a/A

(?<!a\s|A\s)\bshame\b

To exclude the modifying WORD, I was trying to use ?\w in the lookbehind grep, but it just wouldn't work - the grep below without ? runs and it still excludes examples such as a shame, but it still returns the undesired examples such as a great shame or a crying shame - see concordance lines (3) and (4) in the sample text below:

    (?<!a\s|A\s|a\b\w\b|A\b\w\b)\bshame\b

The tool I'm using to implement regex is AntConc, which supports Perl regular expressions.

Sample text with two irrelevant examples (3 & 4) after using the search string below

(?<!a\s|A\s)\bshame\b

---

1 (match shame)

, people ogling from the sidelines.  If you want a closer look, you have to ring for entry and wait to be admitted.  I guess me and Saul just have no shame (or just know the benefits of our bank accounts being in hard currencies), because we wandered into plenty.  Lots and lots of little boutiques and edgily designed fashion stores with music blaring.& abbutterflie.txt 47 1

2 (match shame)

last twenty years and I've experienced all sorts of biggotry but I seriously thought that anti black nazism in football wass a thing of the past. You should all hang your heads in shame, bunch of [badword]s. adamdphillips.txt 57 1

3 (don't match shame)

me monetarily as I wasn't that close to her, but she was really good friends with the other girl and it's messed that up for them a bit, which is a great shame. Anyway, Holly and I have since found somewhere to move in just the two of us. It's going to cost an absolute fortune and I'm going to be eating basics beans on aderyn.txt 60 1

4 (don't match shame)

are loads of amazingly good bands out there, gigging up and down the country who will never get signed because no-one can figure out how to market them, and this is a crying shame. There are artists out there like <a href="http://www.angelsintheabattoir.com/" rel="nofollow">Thea Gilmore</a> and <a href="http://blog.amandapalmer.net/" rel="nofollow"> Amanda Palmer& aderyn.txt 60 2

5 (match shame)

/><br />"There is no better time to show these terrorists that we have no fear of them. Instead we are forced, through the cowardly acts of our superiors, to hide in shame."<br /><br />But Herb Wiseman, high school consultant for Lee County, Florida, pointed to the July 7 London bombings.<br /><br />"What happens if kids get on aggy91.txt 64 1

Answer 1

Because variable length negative lookbehinds are not allowed, the approach in your previous question's answer won't transfer to this one.

I've gone with a (*SKIP)(*FAIL) pattern. This will match and discard the disqualified matches, and only retain qualifying matches:

/[Aa]n?( \w+)? shame(*SKIP)(*FAIL)|shame/ 3844 steps (Demo)

Or if you wish to include word boundary metacharacters:

/\b[Aa]n?( \w+)? shame\b(*SKIP)(*FAIL)|\bshame\b/ 4762 steps (Demo)