Editors

.rayfold is a language, so it gets what a language gets: errors as you type, completion, hover, go to definition and an outline. @rayfold/lsp is a language server that reads a schema with the same parser and validator the runtime uses, so what an editor underlines is what rayfold check reports, in the same words.

npm install --save-dev @rayfold/cli @rayfold/lsp
npx rayfold lsp        # speaks the protocol over stdin and stdout

What you ask	What you get
errors as you type	every syntax error, and every validation finding placed on the declaration it is about
completion	declaration keywords; annotations, each with where it is allowed; type names in a type position
hover	the declaration, its description and its annotations; an operation shows its signature, what it throws and what it emits
go to definition	from a type reference to its declaration
outline	types with their fields, and the operations

Visual Studio Code

editors/vscode in this repository is a small extension with the language's grammar: highlighting, comments and brackets for .rayfold. Copy it into ~/.vscode/extensions (or open it and press F5 to run it in a second window).

To get the diagnostics and the rest, start the server from an extension of your own with vscode-languageclient:

const { LanguageClient, TransportKind } = require("vscode-languageclient/node");

const client = new LanguageClient(
  "rayfold",
  "Rayfold",
  { command: "npx", args: ["rayfold", "lsp"], transport: TransportKind.stdio },
  { documentSelector: [{ scheme: "file", language: "rayfold" }] },
);
client.start();

Neovim

vim.filetype.add({ extension = { rayfold = "rayfold" } })
vim.api.nvim_create_autocmd("FileType", {
  pattern = "rayfold",
  callback = function()
    vim.lsp.start({ name = "rayfold", cmd = { "npx", "rayfold", "lsp" }, root_dir = vim.fn.getcwd() })
  end,
})

Anything else

Any editor that speaks LSP over stdio works: the command is rayfold lsp, and the server needs nothing else. In a program of your own, diagnosticsFor(text) from @rayfold/lsp returns the same findings as a plain function, and RayfoldLanguageServer takes the protocol's messages directly if you have a channel that is not a pipe.