Rhai - Embedded Scripting for Rust
=================================
[](http://travis-ci.org/jonathandturner/rhai)
[](https://github.com/license/jonathandturner/rhai)
[](https://crates.io/crates/rhai/)
[](https://crates.io/crates/rhai/)
[](https://docs.rs/rhai/)
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`
Standard features
-----------------
* Easy-to-use language similar to JavaScript+Rust with dynamic typing.
* Tight integration with native Rust [functions](https://schungx.github.io/rhai/rust/functions.html) and [types]([#custom-types-and-methods](https://schungx.github.io/rhai/rust/custom.html)), including [getters/setters](https://schungx.github.io/rhai/rust/getters-setters.html), [methods](https://schungx.github.io/rhai/rust/custom.html) and [indexers](https://schungx.github.io/rhai/rust/indexers.html).
* Freely pass Rust variables/constants into a script via an external [`Scope`](https://schungx.github.io/rhai/rust/scope.html).
* Easily [call a script-defined function](https://schungx.github.io/rhai/engine/call-fn.html) from Rust.
* Fairly low compile-time overhead.
* Fairly efficient evaluation (1 million iterations in 0.3 sec on a single core, 2.3 GHz Linux VM).
* Relatively little `unsafe` code (yes there are some for performance reasons, and most `unsafe` code is limited to
one single source file, all with names starting with `"unsafe_"`).
* Re-entrant scripting engine can be made `Send + Sync` (via the `sync` feature).
* [Function overloading](https://schungx.github.io/rhai/language/overload.html).
* [Operator overloading](https://schungx.github.io/rhai/rust/operators.html).
* Dynamic dispatch via [function pointers](https://schungx.github.io/rhai/language/fn-ptr.html).
* Some support for [object-oriented programming (OOP)](https://schungx.github.io/rhai/language/oop.html).
* Organize code base with dynamically-loadable [modules](https://schungx.github.io/rhai/language/modules.html).
* Serialization/deserialization support via [serde](https://crates.io/crates/serde) (requires the `serde` feature).
* Scripts are [optimized](https://schungx.github.io/rhai/engine/optimize.html) (useful for template-based machine-generated scripts) for repeated evaluations.
* Support for [minimal builds](https://schungx.github.io/rhai/start/builds/minimal.html) by excluding unneeded language [features](https://schungx.github.io/rhai/start/features.html).
Protection against attacks
--------------------------
* Sand-boxed - the scripting engine, if declared immutable, cannot mutate the containing environment unless explicitly permitted (e.g. via a `RefCell`).
* Rugged - protected against malicious attacks (such as [stack-overflow](https://schungx.github.io/rhai/safety/max-call-stack.html), [over-sized data](https://schungx.github.io/rhai/safety/max-string-size.html), and [runaway scripts](https://schungx.github.io/rhai/safety/max-operations.html) etc.) that may come from untrusted third-party user-land scripts.
* Track script evaluation [progress](https://schungx.github.io/rhai/safety/progress.html) and manually terminate a script run.
For those who actually want their own language
---------------------------------------------
* Use as a [DSL](https://schungx.github.io/rhai/engine/dsl.html).
* Restrict the language by surgically [disabling keywords and operators](https://schungx.github.io/rhai/engine/disable.html).
* Define [custom operators](https://schungx.github.io/rhai/engine/custom-op.html).
* Extend the language with [custom syntax](https://schungx.github.io/rhai/engine/custom-syntax.html).
Documentation
-------------
See [The Rhai Book](https://schungx.github.io/rhai) for details on the Rhai scripting engine and language.
Playground
----------
An [Online Playground](https://alvinhochun.github.io/rhai-demo/) is available with syntax-highlighting editor.
Scripts can be evaluated directly from the editor.
License
-------
Licensed under either of Apache License, Version
2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.