Custom request locate types

[xvw]

Add a custom request for merlin-locate-types

cc @liam923, the major difference of Merlin is the inclusion of the field set which is a compact representation of every reacheables types.

[voodoos]

• I think the result spec here does not match the actually returned json ? Data objects have type and result fields

• "every occured type" sounds very wrong 😅

• Also, could you elaborate on the expected usage of the "set" field ? Does it provide information that is not available otherwise ?

[xvw]

Currently, in Emacs with the in-house xref extension, and in VSCode, the UI is very limitated, so from my POV, for the moment, we do not know how to deal with that kind of structural answer. So the set is just a compact way to handle every "reachable type", since we do not rebuilt the type expression inside the client.|
(So just iterating on set seems legit)

[voodoos]

But could this compact representation be inferred from the rest of the result on the client side ? If it is, then is it really worth it to make the protocol more complex to spare that work to the clients ? (not saying we shouldn't, just trying to weight the pro and cons)

[xvw]

But could this compact representation be inferred from the rest of the result on the client side ?

Yes.

If it is, then is it really worth it to make the protocol more complex to spare that work to the clients ?

Yes I think it make sense when it is possible.
For me, the goal of the protocol is to give a quick-as-possible way to extend clients, so I expect from a client perspective to reduce the logic to handle at the client side. (Like for Type Enclosing)

[voodoos]

Alright. (Still need to fix the doc so that it matches the actual results I think)