Parse piped expressions to Maxima's abs function

[mattvague]

Would be really nice if tex2max supported parsing strings like ln|x| and transpiled them to ln(abs(x)). Seems doable, and I don't mind taking this on as I need it as soon as possible but if I could get some advice on where/how to start that'd be awesome. Thanks!

[andstor]

I have added some basic support for absolute value symbols in the branch feat/abs.

However, since we have based grouping of expressions on the distinction of opening "(" and closing parenthesis ")", braces and brackets, parsing "|" symbols is considerably more difficult. We should make use of the "\left" and "\right" macros to determin if it is a opening or closing pipe. Other macros that should be supported must also be researched further.

Please, feel free to try to fix the problems marked with "TODO" in the post-parser.js file. Alternativley, implement the "\left" and "\right" macros.

[mattvague]

@andstor Ah, awesome thank you! Yeah I imagined that was why it wasn't in master. I'll take a look and see how hard I think it would be.

One thing I was noticing is I didn't see any unit tests, was wondering if you thought that might be something worth adding to ease development and prevent regressions?

[andstor]

@mattvague Yes, we should definitely add unit testing. I have created an issue #29. Help would be much appreciated.