Ashes for Visual Studio Code

Full language support for the Ashes pure functional programming language.

Features

Syntax highlighting — TextMate grammar for .ash files
Diagnostics — real-time error and warning squiggles from the Ashes language server
Formatting — auto-format on save using the canonical Ashes formatter
Hover — type information and documentation on hover
Go to Definition — jump to function and binding definitions
Completions — context-aware IntelliSense suggestions
Semantic tokens — rich token-level highlighting
Debugging — integrated DAP support with breakpoints, stepping, and variable inspection (GDB / LLDB backends)
Compile / Run / Test — run Ashes programs directly from the editor

Quick Start

Install the extension from the VS Code Marketplace (or build locally).
Open a folder containing .ash files.
The language server starts automatically when you open an Ashes file.
Use Ctrl+F5 to run or Shift+F5 to compile the active file.

Install Toolchain

Run Ashes: Install Toolchain from the Command Palette (Ctrl+Shift+P) to pre-download the compiler, language server, and debug adapter in one step.

Commands

Command	Default Key	Description
Ashes: Compile	`Shift+F5`	Compile the active `.ash` file or project
Ashes: Run	`Ctrl+F5`	Compile and run the active file/project
Ashes: Run Tests	—	Run tests in the workspace or active file
Ashes: Install Toolchain	—	Download compiler, LSP, and DAP binaries

Settings

Setting	Default	Description
`ashes.autoStartLanguageServer`	`true`	Automatically start the language server when an `.ash` file is opened. Set to `false` to disable automatic startup.
`ashes.debugger`	`"gdb"`	Native debugger backend (`gdb` or `lldb`)
`ashes.lspServerPath`	`""`	Override the language server binary path
`ashes.dapServerPath`	`""`	Override the DAP server binary path
`ashes.compilerPath`	`""`	Override the compiler binary path

Debugging

Compile your program with --debug:

ashes compile --debug myprogram.ash -o myprogram

Add a launch configuration (or let the extension generate one):

{
  "name": "Ashes: Launch",
  "type": "ashes",
  "request": "launch",
  "program": "${workspaceFolder}/out/${workspaceFolderBasename}",
  "cwd": "${workspaceFolder}",
  "stopOnEntry": false,
}

Optional pre-launch task:

{
  "label": "ashes: compile (debug)",
  "type": "shell",
  "command": "${command:ashes.getCompilerPath}",
  "args": [
    "compile",
    "--debug",
    "${file}",
    "-o",
    "${workspaceFolder}/out/${workspaceFolderBasename}",
  ],
  "group": {
    "kind": "build",
    "isDefault": true,
  },
  "problemMatcher": [],
}

The ${command:ashes.getCompilerPath} variable lets the extension provide the configured, bundled, or downloaded compiler path without requiring ashes to be installed on your shell PATH.

Press F5 to start debugging.

A Taste of Ashes

import Ashes.IO as io
import Ashes.List as list

type Shape =
    | Circle(Float)
    | Rect(Float, Float)

let area = fun (s) ->
    match s with
        | Circle(r) -> 3.14159 * r * r
        | Rect(w, h) -> w * h

in
    [Circle(5.0), Rect(3.0)(4.0), Circle(1.0)]
    |> list.map(area)
    |> list.map(io.print)

Workspace Trust

This extension requires a trusted workspace because it downloads and executes external toolchain binaries. In an untrusted workspace, all download-related features are disabled and an informational message is shown.

Requirements

VS Code 1.110+
Node 20.19+ (extension host)
Linux x64, Linux arm64, or Windows x64

License

MIT — see LICENSE.

Ashes Programming Language

Mattias Högnäs