GameScript

GameScript is a lightweight, indentation-based scripting language and toolchain built for game development. It compiles to a compact bytecode format executed by a small embeddable VM, and ships with a full Language Server for first-class editor support.

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Language at a Glance

GameScript has three scalar types (bool, int, string), four method kinds, and a prefix-based identifier system that makes every symbol's role visible at a glance:

// constants (.const)
int ^npc_knight = 2

// context variables (.context) — backed by a host-provided slot
bool %logged_in = 0

// methods (.gs)
command print(string $value)          // host-implemented opcode, no body

func greet(string $name)             // regular function, returns to caller
    string $msg = "Hello, " + $name
    print($msg)

label do_login()                     // one-way jump (GOTO), never returns
    ~greet("adventurer")

mn_button_1 login:submit()            // trigger — UI event entry point
    @do_login()

Kind	Prefix	Returns?	Notes
func	~	✅	Standard function; returns to caller
label	@	❌	One-way jump; never returns
command	—	✅	Declares a host opcode; no body allowed
trigger	—	❌	Event entry point; cannot be called from script

Symbol	Prefix	Declared in
Local var	$	.gs
Constant	^	.const
Context var	%	.context

See GUIDE.md for the full language reference, including tuple returns, type rules, and the bytecode compiler API.

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Repo Layout

Folder	Purpose
GameScript.Language/	Lexer, parser, AST, visitors (index, semantic, type), bytecode compiler
GameScript.Bytecode/	Bytecode VM and runtime (ScriptState, ScriptRunner)
GameScript.LanguageServer/	LSP server executable
GameScript.Vscode/	VS Code extension
GameScript.VisualStudio/	Visual Studio 2022 extension

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NuGet Packages

Package	Purpose
GameScript.Bytecode	Embed the VM — register opcode handlers, create ScriptState, run bytecode.
GameScript.Language	Full toolchain — parse source, build the symbol index, run analysis passes, compile to bytecode.

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Editor Support

The VS Code extension (GameScript.Vscode) bundles the language server and provides:

• Semantic syntax highlighting for .gs, .const, and .context files
• Completions, hover tooltips, and real-time diagnostics
• Go to Definition, Find All References, Document Highlights
• Rename Symbol, Document Symbols, Workspace Symbols
• Syntax highlighting for Object Definition files (.varp, .item, .npc, .menu, .obj, .tile)

A Visual Studio 2022 extension (GameScript.VisualStudio) is also available.

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Building

git clone https://github.com/Juiix/GameScript.git
cd GameScript
dotnet build

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Contributing

Pull requests are welcome. Please open an issue first to discuss major changes. See CONTRIBUTING.md for coding standards and branch workflow.

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License

GameScript is licensed under the Apache License 2.0 — see LICENSE for details.