Chasm Language Support

Language support for Chasm — a lightweight scripting language designed for games and real-time tools.

Features

Syntax highlighting — keywords, types, atoms, string interpolation, module attributes
Diagnostics — type errors, undefined variables, and missing end blocks shown inline
Hover documentation — hover any builtin, keyword, or user-defined function for its signature
Completions — keywords, builtins, user functions, module attributes, and array/struct methods (.get, .set, .push, etc.)
Go to definition — jump to def/defstruct/enum declarations
Document symbols — outline view for all functions, structs, and enums
Code formatting — auto-format on save
CodeLens — ▶ Run button above on_tick/on_draw/main functions
Snippets — tick, draw, fn, struct, for, if, game, with, and more

Requirements

The LSP features (diagnostics, hover, completions, go-to-definition) require the chasm-lsp binary on your PATH. Install it with the Chasm installer:

curl -fsSL https://raw.githubusercontent.com/Chasm-lang/Chasm/main/install.sh | sh

Extension Settings

Setting	Default	Description
`chasm.serverPath`	`""`	Path to `chasm-lsp`. Leave empty to use PATH.
`chasm.chasmPath`	`"chasm"`	Path to the `chasm` CLI for running files.

Quick Start

@score :: script int = 0

def on_tick(dt :: float) do
  @score = @score + 1
end

def on_draw() do
  draw_text("Score: #{@score}", 10.0, 10.0, 24, 0xFFFFFFFF)
end

Language Overview

Lifetimes — frame (cleared each tick), script (survives ticks), persistent (survives reload)
Structs — value types with update syntax: e with { x: new_x, y: new_y }
Enums — tagged unions with optional payloads
Arrays — array_fixed(n, default) for arena-backed arrays, array_new(cap) for heap arrays
String interpolation — "Score: #{@score}"

Full language reference: SPEC.md

Chasm