Improved tooltip: functions, tuples, etc

[rongcuid]

This is an attempt to fix #631.

I have implemented the behavior specified in the issue, allowing tooltip for f when Shift-Tab is pressed inside a function call f(x, y, ... |) or right outside the call f(x, y, ...)|. | is cursor. Detailed behavior is in docstring.

The current implementation has some string hacks which I consider ugly (explained thoroughly, I hope, in docstrings). If I can dig deeper, I prefer an implementation using a proper Julia language parser. Maybe one that comes from Julia itself.

In any case, I tested with quite a few of my Notebooks, and they all seem to work well.

I forgot to squash the commits, though.

[stevengj]

Would be good to add a test/completion.jl with some tests for get_token.

[stevengj]

I agree that it would be nice to use the Julia parser; the basic issue is that the user might be asking for help on code they haven't finished writing yet…

[rongcuid]

I will try quickly adding some test cases. It's the first time I develop Julia packages so I will need to check out some docs...

[rongcuid]

I have changed behavior slightly to make sure the basic x + y + z works, giving x, y, and z respectively. Further making the completion more robust might be out of scope for my goals, so I propose to merge this as an intermediate solution which provides a slight quality of life improvement. It should be good enough for many common cases.

[rongcuid]

As a note, the julia tokenizer might be helpful for a better solution:

https://github.com/JuliaLang/Tokenize.jl

[rongcuid]

Do you have any plan on merging? I think the current state is good enough for an intermediate improvement.

[rongcuid]

Any updates?

[rongcuid]

Any activities on this? @stevengj can this be merged, or are there some feedback?

[rongcuid]

Any more reviews?

[rongcuid]

Do you think this is mergable or is it too hacky to be put into mainline? I have been waiting for a decision for quite a while.

[rongcuid]

Is there anything I still need to do? Or is this superseded by some other patches?