[codemirror_mode_extensions] add new nbextension

[jcb91]

This is a small nbextension adding an extension to the codemirror octave mode, because I got frustrated while using an octave kernel from metakernel. I've submitted this extension to codemirror & it's been merged, but it won't make it into notebook for a while, so I'm adding it here for now. We could also add similar extensions for other codemirror modes in future

[juhasch]

👍
Commenting works for me. I can't get codefolding to work with Matlab though.

[jcb91]

ok, I didn't look at codefolding yet, just added what I'd found on other codemirror modes. Did you try octave as well, or just MATLAB?

For future reference, the CodeMirror PR is codemirror/codemirror5#4570

[juhasch]

Actually, this is my 'fault'. In the codefolding extension, the folding options are hardcoded currently.
Let me see if this can be changed.

[juhasch]

OK, I fixed the codefolding extension and removed the hardcoded folding type setting in PR #908.

However, for Matlab/Octave I don't think indent folding is correct. This is more of a convention, the language itself doesn't care about indenting.

[jcb91]

However, for Matlab/Octave I don't think indent folding is correct. This is more of a convention, the language itself doesn't care about indenting.

Yes, you're absolutely right, I just added it as a stop-gap, since I didn't have the time to find out how to implement more complex folding in CodeMirror. I think it requires the mode to implement it itself, but I'll have a think.

[juhasch]

I think we can merge it.

[jcb91]

Ok, I've made a proper fold mode for octave, but haven't managed to get it to load correctly yet, so I'll merge as-is for now.

[juhasch]

Cool, I look forward to that!

[jcb91]

It'll be a while coming I'm afraid, as I'm away from laptop for probably the rest of this week...