Syntax highlighting, inline diagnostics, and format on save for .lemma files. The extension starts the Lemma LSP binary; formatting and diagnostics come from the LSP.
Install from this repo (development)
Build the LSP (from the Lemma repo root):
cargo build --release -p lsp
Binary: target/release/lsp.
Install the extension in VS Code / Cursor:
Option A: Open this folder (engine/lsp/editors/vscode) in VS Code and press F5 to run the Extension Development Host; or
Option B: From this folder run npm run package, then install the generated .vsix via Extensions → ... → Install from VSIX.
LSP discovery:
If your workspace root is the Lemma repo, the extension uses target/release/lsp automatically.
Otherwise, set the path in settings: Lemma: Lsp Server Path (lemma.lspServerPath) to the full path of the lsp binary, or ensure lsp is on your PATH.
Format on save not working
Format on save uses the LSP. If the LSP does not start, formatting (and diagnostics) will not work.
Check that the LSP is running
Open a .lemma file, then View → Output and select Lemma Language Server.
You should see a line like “Lemma LSP server initialized”. If you see a spawn/ENOENT error, the binary was not found.
Fix the LSP path
When not in the Lemma repo: set lemma.lspServerPath to the full path to the lsp binary (e.g. /path/to/lemma/target/release/lsp).
Or build the LSP and add the directory containing lsp to your PATH.
Confirm formatter for Lemma
In a .lemma file, open the Command Palette and run Format Document. If it works, format-on-save should work once Editor: Format On Save is on and the default formatter for [lemma] is this extension (both are set by the extension’s default config).
Marketplace install
The extension is published under the Lemma publisher. Search for Lemma Language or lemma-language in the Extensions view.
After first publish: The marketplace can take from about 10 minutes up to several hours to index a new or updated extension. If you don’t see it, wait and try again, or search by publisher: @lemma.
LSP when installed from marketplace: The extension does not bundle the LSP binary. You must either have the Lemma repo open (with target/release/lsp built) or set lemma.lspServerPath to your lsp binary. Installing from the marketplace is mainly for users who also build Lemma from source or have lsp on their system.
