Question

I would like to find a regex that will pick out all commas that fall outside quote sets.

For example:

'foo' => 'bar', 'foofoo' => 'bar,bar' 

This would pick out the single comma on line 1, after 'bar',

I don’t really care about single vs double quotes.

Has anyone got any thoughts? I feel like this should be possible with readaheads, but my regex fu is too weak.

Answer 1

This will match any string up to and including the first non-quoted ‘,’. Is that what you are wanting?

/^([^']|'[^']*')*?(,)/ 

If you want all of them (and as a counter-example to the guy who said it wasn’t possible) you could write:

/(,)(?=(?:[^']|'[^']*')*$)/ 

which will match all of them. Thus

'test, a 'comma,', bob, ',sam,',here'.gsub(/(,)(?=(?:[^']|'[^']*')*$)/,';') 

replaces all the commas not inside quotes with semicolons, and produces:

'test; a 'comma,'; bob; ',sam,';here' 

If you need it to work across line breaks just add the m (multiline) flag.