Editor setup¶

a816-lsp-server ships with the package and speaks LSP over stdio. Any editor that can launch an LSP for a file extension can use it. Configure it for .s and .i files.

See LSP for the full feature list and the a816.toml / ;! a816-lsp entrypoint discovery rules.

Neovim (nvim-lspconfig)¶

vim.filetype.add({ extension = { s = "a816", i = "a816" } })

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

if not configs.a816 then
    configs.a816 = {
        default_config = {
            cmd = { "a816-lsp-server" },
            filetypes = { "a816" },
            root_dir = lspconfig.util.root_pattern("a816.toml", ".git"),
            single_file_support = true,
        },
    }
end

lspconfig.a816.setup({})

VS Code¶

There's no published extension yet. Wire a816-lsp-server through a generic LSP client extension (e.g., mattn.lsp or SteefH.external-formatters), or write a 30-line extension:

// .vscode/settings.json
{
    "files.associations": {
        "*.s": "a816",
        "*.i": "a816"
    }
}

// extension.ts (snippet)
import * as vscode from "vscode";
import { LanguageClient, ServerOptions, TransportKind } from "vscode-languageclient/node";

export function activate(context: vscode.ExtensionContext) {
    const serverOptions: ServerOptions = {
        run:   { command: "a816-lsp-server", transport: TransportKind.stdio },
        debug: { command: "a816-lsp-server", args: ["--verbose"], transport: TransportKind.stdio },
    };
    const client = new LanguageClient(
        "a816",
        "a816 LSP",
        serverOptions,
        { documentSelector: [{ scheme: "file", language: "a816" }] },
    );
    client.start();
    context.subscriptions.push(client);
}

Helix¶

languages.toml:

[[language]]
name = "a816"
scope = "source.a816"
file-types = ["s", "i"]
roots = ["a816.toml"]
language-servers = ["a816-lsp-server"]
indent = { tab-width = 4, unit = "    " }

[language-server.a816-lsp-server]
command = "a816-lsp-server"

Emacs (eglot)¶

(define-derived-mode a816-mode prog-mode "a816"
  "Major mode for 65c816 assembly.")

(add-to-list 'auto-mode-alist '("\\.s\\'" . a816-mode))
(add-to-list 'auto-mode-alist '("\\.i\\'" . a816-mode))

(with-eval-after-load 'eglot
  (add-to-list 'eglot-server-programs
               '(a816-mode . ("a816-lsp-server"))))

(add-hook 'a816-mode-hook #'eglot-ensure)

JetBrains IDEs¶

The repository ships an IntelliJ plugin under intellij/. Build and install it from sources, or wire a816-lsp-server through the Generic LSP plugin if you prefer a thinner integration.

Format-on-save¶

Most LSP clients can route format-on-save through the server's formatting capability. The server runs the same fluff formatter as a816 format, so save-formatted output matches what CI's a816 format --check expects.

Neovim:

vim.api.nvim_create_autocmd("BufWritePre", {
    pattern = { "*.s", "*.i" },
    callback = function() vim.lsp.buf.format({ async = false }) end,
})

VS Code:

{
    "[a816]": {
        "editor.formatOnSave": true
    }
}

Sanity check¶

After wiring up, opening a .s file should produce:

• Parser errors as red squigglies (source: a816 lsp).
• Fluff lint hits as yellow squigglies (source: a816 fluff, carrying the rule code: DOC001, E501, N801, …).
• Hover over a label / macro / scope / .import token yields the attached docstring.
• Goto-definition hops across modules.