Editor Support¶

Kaappi includes a Language Server Protocol (LSP) server for IDE integration.

VS Code¶

From source¶

git clone https://github.com/kaappi/vscode-kaappi
cd vscode-kaappi
npm install
npm run compile

Then press F5 in VS Code to launch an Extension Development Host, or copy the folder to ~/.vscode/extensions/.

Features¶

Syntax highlighting for .scm, .sld, .ss, .sls files
Auto-completion of all 600+ built-in procedures and your definitions
Hover information showing type and arity of procedures
Real-time diagnostics for parse and compile errors
Bracket matching and auto-closing for parentheses
Comment toggling — line (;) and block (#| |#)

Configuration¶

Setting	Default	Description
`kaappi.lspPath`	`kaappi-lsp`	Path to the kaappi-lsp binary

If kaappi-lsp is not in your PATH:

{
  "kaappi.lspPath": "/usr/local/bin/kaappi-lsp"
}

Language Server (kaappi-lsp)¶

The kaappi-lsp binary is included with Kaappi and built alongside the main interpreter. It communicates via JSON-RPC over stdin/stdout following the Language Server Protocol.

Capabilities¶

Feature	Description
Diagnostics	Parse and compile errors on every file change
Completion	All global symbols, filtered by prefix at cursor
Hover	Type name and arity for any symbol
Document sync	Full text synchronization

Using with other editors¶

Any editor with LSP support can use kaappi-lsp. Configure it as a stdio language server for .scm files:

Neovim (nvim-lspconfig):

vim.api.nvim_create_autocmd("FileType", {
  pattern = "scheme",
  callback = function()
    vim.lsp.start({
      name = "kaappi-lsp",
      cmd = { "kaappi-lsp" },
    })
  end,
})

Emacs (eglot):

(add-to-list 'eglot-server-programs '(scheme-mode . ("kaappi-lsp")))

Helix (languages.toml):

[[language]]
name = "scheme"
language-servers = ["kaappi-lsp"]

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

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