Aion for VS Code

Language support for Aion, the scripting-style language that compiles to a native binary.

Features

Syntax highlighting for .aion files: comments (nested block comments and /** */ docs), strings with $name and ${expr} interpolation, triple-quoted and raw strings, characters, all number forms, declarations, types, operators and the standard library's built-ins.
aion.project is recognised by its exact file name and has its own highlighting.
File icons: the Aion logo for .aion files, and the logo with a gear for aion.project. They are used where the active file icon theme has no icon of its own for these files; a theme that does, such as Material Icon Theme, keeps its own.
Go to Definition (Ctrl+click or F12) on a function, type, variable, parameter, field, enum variant or import. It follows import and from … import to the file in your project, and into your dependencies: a path dependency, and a git dependency that aion install downloaded into the project's aion-dependencies/ folder (the commit comes from aion.lock). Git dependencies kept in the shared cache are not followed. It works from the text alone, so it needs no compiler. A call like shape.area() lists every area in the type hierarchy, because the extension does not know the type of shape. The standard library is built into the compiler, so its names have no file to open.
Problems from aion check, shown in the editor when a file is opened or saved.
Run Aion File: a play button in the editor title bar (like the Python extension), the editor and explorer context menus, the command palette, and Ctrl+Alt+R (Cmd+Alt+R on macOS).
Build Aion File, Check Aion File, Run Aion Tests and Open Aion REPL commands.
Format Document through aion fmt, so format-on-save works.
Tasks: an aion task type with a problem matcher, so errors from a build link back to the code.
Snippets for functions, types, when, loops, try, tasks and more.
Bracket matching, auto-closing pairs, comment toggling, indentation and // region folding.

Requirements

The aion compiler must be installed and on your PATH, or aion.path must point at it. See the Aion repository for installation. Highlighting and snippets work without it.

Settings

Setting	Default	What it does
`aion.path`	`aion`	The compiler to run: a command on `PATH` or a full path.
`aion.compilerArgs`	`[]`	Options for the compiler when running or building, e.g. `["-O3", "--no-trace"]`.
`aion.run.programArgs`	`[]`	Arguments passed to your program (read with `args()`).
`aion.run.command`	empty	A command line to run in the terminal instead of `aion run`. See below.
`aion.saveBeforeRun`	`true`	Save the file before running, building or checking it.
`aion.check.run`	`onSave`	`onSave` checks files when opened and saved; `never` checks only on request.

A custom run command

By default Run Aion File runs aion run -O… <file> -- <args> as a VS Code task. Set aion.run.command to run something else in the integrated terminal:

{
  "aion.run.command": "${aion} run -O3 ${file}"
}

Variables: ${aion} (the compiler, from aion.path), ${file}, ${fileDirname}, ${fileBasename}, ${fileBasenameNoExtension} and ${workspaceFolder}. A value with a space in it is quoted. Any other ${...} is left for your shell.

Tasks

{
  "version": "2.0.0",
  "tasks": [
    { "type": "aion", "command": "run", "file": "${file}", "flags": ["-O3"], "args": ["--verbose"], "label": "run optimised" },
    { "type": "aion", "command": "test", "group": "test", "label": "aion test" }
  ]
}

command is one of run, build, check and test. Without file, the project (aion.project) is used.

Development

npm install
npm test

Open the folder in VS Code and press F5 to start an Extension Development Host. The extension is plain JavaScript with no build step. npm test also tokenizes every program in a neighbouring checkout of the Aion repository (../aion, or the path in AION_REPO) to check the grammar against real code.

The icons come from node scripts/make-icons.js, which draws the logo and the gear into icons/, and renders icons/icon.png, the marketplace picture.

Package it with npx @vscode/vsce package.

License

Apache-2.0. See LICENSE.

Aion Support

AionLang