How do I use PositiveLookbehind to match multiple strings in GREP styles?

Question

I'm trying to format a keyword(s) that comes after specific string. For example, I want to bold the words, "happy", "sad", and "angry", but only if they are preceded by "be" or "become". This is an example of what I expect to be bolded:

I am happy, but I will be angry soon. Though she is sad now, she will become happy.

I have tried to GREP it like this:

(?<=(be|become).)(happy|sad|angry)

This seems to work on other programs but not Indesign. I could construct the arguments "be" and "become" separately like this: (?<=be)(happy|sad|angry)|(?<=become)(happy|sad|angry), but it's not feasible when there are a lot of strings I need to match.

Answer 1

try using the InDesign script “FindChangeByList.jsx”. Find out about it here:

InDesign: how to run multiple find/change queries at once

In your instance, after first adding the “bold” character style to your document, you would add these lines to the “FindChangeList.txt”, then run the script.

grep    {findWhat:"(?<=be.)(happy|sad|angry)"}  {appliedCharacterStyle:"bold"}  {includeFootnotes:true, includeMasterPages:true, includeHiddenLayers:true, wholeWord:false}

grep    {findWhat:"(?<=become.)(happy|sad|angry)"}  {appliedCharacterStyle:"bold"}  {includeFootnotes:true, includeMasterPages:true, includeHiddenLayers:true, wholeWord:false}

Answer 2

It doesn't work because a lookbehind assertion has to be fixed width. Use this instead:

\b(?<=[become]\s)(happy|sad|angry)

\b for word boundary.

\s for space, instead of . (which matches any character).