Please improve pylance's parameter prompt layout style and provide function documentation

[CatNofishing]

Compared with jedi, pylance's parameter prompt typesetting is too dense and not suitable for reading. In addition, for the same function, pylance only has parameter prompts, but no function documentation.

[CatNofishing]

@jakebailey @erictraut @mattetti

[jakebailey]

I had thought the original issue here would be fixed by the fixes for type aliases over-expanding, but it appears not:

Even though this is defined as:

def scatter(
    x: ArrayLike,
    y: ArrayLike,
    s: Optional[Union[Scalar, ArrayLike]] = ...,
    c: Optional[Union[_ColorLike, Sequence[float], Sequence[_ColorLike]]] = ...,
    marker: Optional[MarkerStyle] = ...,
    cmap: Optional[Colormap] = ...,
    norm: Optional[Normalize] = ...,
    vmin: Optional[Scalar] = ...,
    vmax: Optional[Scalar] = ...,
    alpha: Optional[Scalar] = ...,
    linewidths: Optional[Union[Scalar, ArrayLike]] = ...,
    verts: Optional[Any] = ..., # not documented?
    edgecolors: Optional[Union[Literal["face", "none"], _ColorLike, Sequence[_ColorLike]]] = ...,
    *,
    plotnonfinite: bool = ...,
    data: Optional[Any] = ...,
    **kwargs: Any
) -> PathCollection: ...

And should be displayed much smaller thanks to the aliases.

[erictraut]

Aliases are still expanded when used within unions because the resulting union needs to be deduped. I don't see any straightforward way to avoid this. Typescript also expands type aliases for unions.

[jakebailey]

I can understand within a union (unfortunate), but ArrayLike is an alias itself and its name is being elided for the x and y parameters.

[erictraut]

Yes, you're correct @jakebailey. There are places where the the type checker was transforming types unnecessarily and removing the type alias information in the process. I've checked in a fix, and the ArrayLike alias is now preserved. I don't know if this change will make it into this week's Pylance build. It might be too late. If not, it will be in the following release.

[jakebailey]

I'll try to sneak it in. The fix saves a few lines, though the nested unions still get expanded (as you said).

[jakebailey]

Okay, I've gotten it in. I won't mark this issue as closed quite yet (as I believe this is the overall tracking issue for "tooltips are too big").

[CatNofishing]

☺Thanks for your reply!

[CatNofishing]

To be honest, the readability of parameter prompts is really poor. You can't even quickly distinguish which one is the formal parameter and which is the default parameter. You have to scan such a long function signature one by one, and there is no function document

[yvvt0379]

@jakebailey @erictraut Here's my suggestions, and it's up to you to accept or reject: We can show types in a non-monospaced font(say, Segoe UI) and/or in smaller sizes so that they will occupy less space, and in a different background color to make it easier to distinguish them and parameter names apart.

[judej]

Moving this issue to discussion as an enhancement request for comments and upvotes.