HEPH-31: Creating Heph Language Server

[Beloin]

There's a lot to unpack here.

1. Why not use starlark-lsp?

• Too weird. It doesnt have any api to ease or way into custom capabilities
• Also their way to import code was so weird, a custom python file had to be generated to be imported into entrypoint.

2. Why not Use Starlark Parser?

• We won't have custom queries.
• Parsers generate AST not an CST.
• In CST I can look direct into nodes an query specified node in position offset (thus querying and matching position).

3. Why use Python Parser?

• Closer to starlark, we don't have a official starlark parser yet.

4. How to test?

• I have also implemented a Neovim plugin that uses this LSP.
• Available here .

Initial Implemented LSP Capabilities

• Completion
• Declaration
• Hover
• References
• Sync

Not implemented (yet)

• Heph/Starlark modules and structs
• Meaning we dont have any capabilites for heph.canonicalize etc.

Known improvements

1. Use DAG to save relationships from BUILD files
2. Use trie or other prefix trees to make in-memory queries faster

Examples

Function Doc:

Arg Doc:

Completions:

[Beloin]

v1.8.0+ removes ShellCompDirectiveNoMatching.
There's not too much documentation, but for what I could read, the ShellCompDirectiveNoFileComp behaviour is already enough for NoMacthing