Highlight `SquishedCommas`, except at end of line

Question

Following up on this question on how to highlight commas not followed by a space; the accepted answer provides a nice solution for problems like:

func(a, b,c,d)

But it also highlights commas at the end of a line (after longname2):

func(longname1, longname2,
     longname3)

There I would actually like to highlight the opposite case, i.e. if there actually was a space behind longname2, (which is already handled by the highlighting of trailing spaces).

Is there a way to extend/modify this command:

highlight SquishedCommas ctermbg=red guibg=red
match SquishedCommas /, \@!/

To only highlight the SquishedCommas if they are not at the end of a line?

Answer 1

match SquishedCommas /, \@!/

You are actively highlighting commas, that are not followed by a space. But in fact you want to only highlight commas that are not at the end of line and are not followed by a space. I think this change to your :match command will achieve this:

match SquishedCommas /,\%($\| \)\@!/

That will highlight commas, that are not at the end of the line and not followed by a space.

Note: the :match function is a window local function. That means it won't work after splitting a new window.