fix: jump to def/decl/type-def don't stop working after the first jump

[ulugbekna]

Fixes #898

It seems like we shouldn't reuse a pipeline if a pipeline has been constructed for another file.

[rgrinberg]

It seems like we shouldn't reuse a pipeline if a pipeline has been constructed for another file.

But how are we reusing a pipeline used for another file? We create a pipeline for every document.

[rgrinberg]

In any case, it does seem sketchy what we're doing. We can't stop reusing pipelines altogether, but how about we only save the last used pipeline and reuse it for subsequent requests to the same document?

[ulugbekna]

But how are we reusing a pipeline used for another file? We create a pipeline for every document.

AFAIU, a pipeline creation invalidates all previously created pipelines, due the creation manipulating global variables such as Location.input_name in setup_reader_config fn in mocaml.ml.

how about we only save the last used pipeline and reuse it for subsequent requests to the same document?

Yes, that's what I intend to do.

[rgrinberg]

Okay, carry on then. I misunderstood the PR's description then.

[ulugbekna]

On second thought, we have Mpipeline.with_pipeline that implies that there should be more than one pipeline existing. That function invokes Mocaml.with_state that allows to set a set of global refs to a snapshot captured for this particular pipeline. Env.Current_unit_name.t and Location.input_name mutable vars do not seem to be snapshotted.

Also, there's query field in Mconfig.t, which allows specifying file and its directory, so could a pipeline be reused for different files?

I'll try looking at how emacs/vim use merlin's API tomorrow.

[ulugbekna]

I'll make another PR when I figure things out.