jotlang-lsp

The JOTL Language Server — implements the Language Server Protocol (LSP) to provide editor intelligence for .jot files in any editor that supports LSP.

What it provides

• Diagnostics — unknown tags, invalid variants, unclosed blocks, responsive overrides on style attributes, mismatched closers, unterminated strings
• Completions — tag names (filtered by context), variants for the current tag, attribute names valid for the current tag, enum values for attributes like type, root-level directive snippets
• Hover — rich markdown tooltips for sigils, tags (with variants and attributes), individual variants, attributes (with accepted values and responsive capability), and references

Installation

npm install -g jotlang-lsp

This installs the jotlang-lsp binary, which communicates over stdio (the default transport for LSP).

Editor setup

VS Code / Cursor

Install the JOTLANG Language Support extension — it bundles this server internally. No separate installation needed.

Neovim (nvim-lspconfig)

local lspconfig = require('lspconfig')
local configs = require('lspconfig.configs')

if not configs.jotl then
  configs.jotl = {
    default_config = {
      cmd = { 'jotlang-lsp', '--stdio' },
      filetypes = { 'jotl' },
      root_dir = lspconfig.util.root_pattern('package.json', '.git'),
      settings = {},
    },
  }
end

lspconfig.jotl.setup({})

Zed

In your settings.json:

{
  "languages": {
    "JOTL": {
      "language_servers": ["jotlang-lsp"]
    }
  },
  "lsp": {
    "jotlang-lsp": {
      "binary": {
        "path": "jotlang-lsp",
        "arguments": ["--stdio"]
      }
    }
  }
}

Helix

In your languages.toml:

[[language]]
name = "jotlang"
scope = "source.jotlang"
file-types = ["jot"]
language-servers = ["jotlang-lsp"]

[language-server.jotlang-lsp]
command = "jotlang-lsp"
args = ["--stdio"]

Architecture

The server has three layers:

1. Data (src/data/) — static registries of sigils, tags, and attributes. The canonical source of truth for what JOTL knows about itself.
2. Parser (src/parser/) — a lightweight token-stream tokenizer with position indexing. This is separate from the compiler's Peggy grammar because LSP needs per-character classification for hover and cursor queries, not full AST construction.
3. Features (src/features/) — diagnostics, completions, and hover providers. Each consumes the token stream and data registries to produce LSP responses.

The server.ts entry wires the features to the LSP connection and manages per-document analysis caching.

Development

# Build
npm run build

# Type check
npm run typecheck

# Run the smoke test
npm run test

License

MIT