VS Code client for the latform language
server — editor support for Bmad lattice files (*.bmad, *.lat,
*.lat.bmad).
Features provided by the server:
- Go-to-definition for elements, lines, lists, and constants (F12)
- Find all references across the project (Shift+F12)
- Workspace symbols — jump to any name across the project (Ctrl+T)
- Hover — element/constant/line definitions, attribute types & units,
element-type keywords, and builtin functions & constants
- Completion — element types, attributes (for the element's type), defined
names, and builtins, cased to your project's format settings
(triggered on
:, [, ,, and space)
- Rename symbol and all its references (F2)
- Formatting — Format Document and Format Selection
- Semantic highlighting — parser-accurate token colors, layered over the
TextMate grammar. Defined element names are coloured as classes and beamlines
as namespaces (so valid names stand out from typos), element types as
types, attributes as properties, and builtins as functions
- Document highlight — occurrences of the name under the cursor
- Document symbols (outline / breadcrumbs / Ctrl+Shift+O)
- File dependencies — the
call include tree, via the Latform: Show File
Dependencies command
- Code actions / quick fixes (💡) — remove duplicate attribute / unused
constant / override, "use built-in constant", "did you mean…" for unknown
names/types/attributes, inline/extract constant, expand abbreviation, and
suppress a lint
- Diagnostics (parse errors + linter warnings), live as you type
The server is project-aware: with a latform.toml declaring top-level
lattices (or a tao.init), cross-file references resolve across the tree, edits
re-analyze quickly, and on-disk changes are picked up automatically.
The extension also ships a TextMate grammar for basic syntax highlighting that
works even before the server attaches; once connected, the server's semantic
tokens refine it (requires a theme with semantic highlighting enabled, the
default).
Requirements
The latform-lsp server must be resolvable (see configuration below). Install
it with:
pip install 'latform[lsp]'
This pulls in pygls. Verify with
which latform-lsp.
Configuration
| Setting |
Default |
Description |
latform.server.command |
latform-lsp |
Executable to launch. Use an absolute path if the server lives in a virtualenv that is not on your PATH. |
latform.server.args |
[] |
Extra command-line arguments passed to the server. |
latform.server.logLevel |
warning |
Server log verbosity (error / warning / info / debug). Logs appear in the Latform Language Server output channel; debug reports every request. |
latform.server.logFile |
"" |
If set, the server writes logs to this file instead of stderr. |
latform.trace.server |
off |
Trace VS Code ↔ server traffic (off / messages / verbose). |
To format on save, add to your settings:
{
"[bmad]": { "editor.formatOnSave": true }
}
If latform-lsp lives in a virtualenv, point the command at it directly:
{
"latform.server.command": "/path/to/venv/bin/latform-lsp"
}
The Latform: Restart Language Server command (Command Palette) restarts the
server; changing any latform.server.* setting restarts it automatically.
Development
npm install
npm run watch # incremental esbuild bundle into dist/
Press F5 ("Run Extension") to launch an Extension Development Host
with the extension loaded. Open a .bmad or .lat file to activate it.
Package a .vsix:
npx vsce package
Troubleshooting
- Server not found — check
latform.server.command and that latform-lsp
is installed (pip install 'latform[lsp]').
- A feature isn't responding — set
latform.server.logLevel to debug and
open the "Latform Language Server" output channel to see each request handled.
- Inspect traffic — set
latform.trace.server to verbose (protocol-level
JSON-RPC messages).
License
BSD-3-Clause. See LICENSE.
