handle mixed numbers

[ldworkin]

[ldworkin]

Never mind this isn't ready, found some issues 😬

[ldworkin]

Ok it's actually ready now guys!

[evykassirer]

here's a followup thought @aliang8 @ldworkin

This change is very specific for Socratic's use case. Does it make sense for when people actually enter that text? If you were just going to mathsteps and entering -1(7)/(8) ... I guess most people wouldn't do that :p

But I think that very Socratic focused changes could happen in Athena. e.g. you could convert -1(7)/(8) to -1 + 7/8 and just pass that into mathsteps. Just a thought - lemme know what you think about this kind of thing in general for dealing with future parsing errors

[ldworkin]

So re: your thought -- I totally agree that generally anything specific to Socratic should go in Athena! However, in this case, we can't really do that -- because we don't want the pedagogy to involve a conversion to -1 + 7/8. We really want the steps to be as they are above. I agree this is a slightly weird case, but I think it's fine and doesn't really cause any harm. I'm happy to add some more documentation explaining why we do it this way, in case a newcomer sees this code? I'm also happy to add an issue to re-address this sometime in the future, e.g. when we have a custom parser.

[evykassirer]

a little bit of documentation and an issue sounds good :) thanks!