I agree that would be nice, but I think adding this sort of thing would overly-complicate an already extremely dense regular expression.  Something like this would work:
```
FORMAT = re.compile(r"""^(\s+)?(?P<src>\"[^\"]*\"|\'[^\']*\'|\S+)(\s+)?((cells\[)(?P<start>-?[0-9]*):(?P<end>-?[0-9]*)(\]))?(\s+)?$""")
```
But then you end up with a string containing quotation marks if they're used, which adds further complicated post-processing.  Additionally, a regular expression like this is extremely difficult to read, maintain, and understand, even if you're the person who wrote it!

The best option would be to write a simple modular parsing framework to express these things within the submodule, but I don't really have the bandwidth to take that on right now.  Plus, who puts spaces in their filenames anymore? :smile: