highlighting large regions (comments) with font-lock keywords

[Eric Schulte]

Hi,

I'm working on a major mode for a new language [1] which comments
regions between \* ... *\.  I've properly (I believe) instantiated
font-lock keywords, and I have added a function to the
`font-lock-extend-region-functions' list to ensure that both ends of a
comment are always considered at the same time but unfortunately comment
highlighting often does not work.

Specifically, when I first enter a buffer and right after calling
`shen-mode' all comments are properly highlighted, however as I edit and
navigate in the buffer larger comments often lose fontification.

Any thoughts as to the cause of or solution to this problem would be
greatly appreciated.

Thanks -- Eric

Footnotes: 
[1]  https://github.com/eschulte/shen-mode/blob/master/shen-mode.el

-- 
Eric Schulte
http://cs.unm.edu/~eschulte/