Rhai - Embedded Scripting for Rust ================================= ![GitHub last commit](https://img.shields.io/github/last-commit/rhaiscript/rhai?logo=github) [![Build Status](https://github.com/rhaiscript/rhai/workflows/Build/badge.svg)](https://github.com/rhaiscript/rhai/actions) [![license](https://img.shields.io/crates/l/rhai)](https://github.com/license/rhaiscript/rhai) [![crates.io](https://img.shields.io/crates/v/rhai?logo=rust)](https://crates.io/crates/rhai/) [![crates.io](https://img.shields.io/crates/d/rhai?logo=rust)](https://crates.io/crates/rhai/) [![API Docs](https://docs.rs/rhai/badge.svg?logo=docs.rs)](https://docs.rs/rhai/) [![chat](https://img.shields.io/discord/767611025456889857.svg?logo=discord)](https://discord.gg/HquqbYFcZ9) [![Reddit](https://img.shields.io/reddit/subreddit-subscribers/Rhai?logo=reddit)](https://www.reddit.com/r/Rhai) [![Rhai logo](https://rhai.rs/book/images/logo/rhai-banner-transparent-colour.svg)](https://rhai.rs) Rhai is an embedded scripting language and evaluation engine for Rust that gives a safe and easy way to add scripting to any application. Supported targets and builds --------------------------- * All common CPU targets for Windows, Linux and MacOS. * WebAssembly (WASM) * `no-std` * Minimum Rust version 1.49 Standard features ----------------- * Simple language similar to JavaScript+Rust with [dynamic](https://rhai.rs/book/language/dynamic.html) typing. * Fairly efficient evaluation (1 million iterations in 0.3 sec on a single-core, 2.3 GHz Linux VM). * Tight integration with native Rust [functions](https://rhai.rs/book/rust/functions.html) and [types]([#custom-types-and-methods](https://rhai.rs/book/rust/custom.html)), including [getters/setters](https://rhai.rs/book/rust/getters-setters.html), [methods](https://rhai.rs/book/rust/custom.html) and [indexers](https://rhai.rs/book/rust/indexers.html). * Freely pass Rust values into a script as [variables](https://rhai.rs/book/language/variables.html)/[constants](https://rhai.rs/book/language/constants.html) via an external [`Scope`](https://rhai.rs/book/rust/scope.html) - all clonable Rust types are supported; no need to implement any special trait. Or tap directly into the [variable resolution process](https://rhai.rs/book/engine/var.html). * Built-in support for most common [data types](https://rhai.rs/book/language/values-and-types.html) including booleans, [integers](https://rhai.rs/book/language/numbers.html), [floating-point numbers](https://rhai.rs/book/language/numbers.html) (including [`Decimal`](https://crates.io/crates/rust_decimal)), [strings](https://rhai.rs/book/language/strings-chars.html), [Unicode characters](https://rhai.rs/book/language/strings-chars.html), [arrays](https://rhai.rs/book/language/arrays.html) and [object maps](https://rhai.rs/book/language/object-maps.html). * Easily [call a script-defined function](https://rhai.rs/book/engine/call-fn.html) from Rust. * Relatively little `unsafe` code (yes there are some for performance reasons). * Few dependencies (currently only [`smallvec`](https://crates.io/crates/smallvec), [`num-traits`](https://crates.io/crates/num-traits) and [`ahash`](https://crates.io/crates/ahash)). * Re-entrant scripting engine can be made `Send + Sync` (via the `sync` feature). * Compile once to [AST](https://rhai.rs/book/engine/compile.html) form for repeated evaluations. * Scripts are [optimized](https://rhai.rs/book/engine/optimize.html) (useful for template-based machine-generated scripts). * Easy custom API development via [plugins](https://rhai.rs/book/plugins/index.html) system powered by procedural macros. * [Function overloading](https://rhai.rs/book/language/overload.html) and [operator overloading](https://rhai.rs/book/rust/operators.html). * Dynamic dispatch via [function pointers](https://rhai.rs/book/language/fn-ptr.html) with additional support for [currying](https://rhai.rs/book/language/fn-curry.html). * [Closures](https://rhai.rs/book/language/fn-closure.html) (anonymous functions) that can capture shared values. * Some syntactic support for [object-oriented programming (OOP)](https://rhai.rs/book/language/oop.html). * Organize code base with dynamically-loadable [modules](https://rhai.rs/book/language/modules.html), optionally [overriding the resolution process](https://rhai.rs/book/rust/modules/resolvers.html). * Serialization/deserialization support via [serde](https://crates.io/crates/serde) (requires the `serde` feature). * Support for [minimal builds](https://rhai.rs/book/start/builds/minimal.html) by excluding unneeded language [features](https://rhai.rs/book/start/features.html). Protected against attacks ------------------------- * _Don't Panic_ guarantee - Any panic is a bug. Rhai subscribes to the motto that a library should never panic the host system, and is coded with this in mind. * [Sand-boxed](https://rhai.rs/book/safety/sandbox.html) - the scripting engine, if declared immutable, cannot mutate the containing environment unless [explicitly permitted](https://rhai.rs/book/patterns/control.html). * Rugged - protected against malicious attacks (such as [stack-overflow](https://rhai.rs/book/safety/max-call-stack.html), [over-sized data](https://rhai.rs/book/safety/max-string-size.html), and [runaway scripts](https://rhai.rs/book/safety/max-operations.html) etc.) that may come from untrusted third-party user-land scripts. * Track script evaluation [progress](https://rhai.rs/book/safety/progress.html) and manually terminate a script run. For those who actually want their own language --------------------------------------------- * Use as a [DSL](https://rhai.rs/book/engine/dsl.html). * Restrict the language by surgically [disabling keywords and operators](https://rhai.rs/book/engine/disable.html). * Define [custom operators](https://rhai.rs/book/engine/custom-op.html). * Extend the language with [custom syntax](https://rhai.rs/book/engine/custom-syntax.html). Project Site ------------ [`rhai.rs`](https://rhai.rs) Documentation ------------- See [_The Rhai Book_](https://rhai.rs/book) for details on the Rhai scripting engine and language. Playground ---------- An [_Online Playground_](https://rhai.rs/playground) is available with syntax-highlighting editor, powered by WebAssembly. Scripts can be evaluated directly from the editor. License ------- Licensed under either of the following, at your choice: * [Apache License, Version 2.0](https://github.com/rhaiscript/rhai/blob/master/LICENSE-APACHE.txt), or * [MIT license](https://github.com/rhaiscript/rhai/blob/master/LICENSE-MIT.txt) Unless explicitly stated otherwise, any contribution intentionally submitted for inclusion in this crate, as defined in the Apache-2.0 license, shall be dual-licensed as above, without any additional terms or conditions.