The Rhai Book
User’s Guide
Introduction
❱
Features of Rhai
Supported Targets and Builds
What Rhai Isn't
Licensing
Related Resources
Getting Started
❱
Online Playground
Install the Rhai Crate
Optional Features
Packaged Utilities
The Scripting Engine
❱
“Hello, Rhai”
Compile to AST
Raw Engine
❱
Built-in Operators
Scope – Maintaining State
Expressions Only
Options
Examples
❱
Rust
Scripts
Special Builds
❱
Performance
Minimal
no-std
WebAssembly (WASM)
Rust Integration
Introduction
Traits
Register a Rust Function
❱
String Parameters
Generic Functions
Fallible Functions
Dynamic Parameters
NativeCallContext
Override a Built-in Function
Call a Rhai Function from Rust
❱
Create a Rust Closure from a Rhai Function
Operator Overloading
Working with Any Rust Type
❱
Register a Rust Type and Its Methods
Property Getters and Setters
Indexers
Call Method as Function
Collection Types
Disable Custom Types
Printing Custom Types
Modules
❱
Create in Rust
Create from AST
Use a Module
Module Resolvers
❱
Custom Module Resolvers
Self-Contained AST
Plugins
❱
Export a Rust Module
Export a Rust Function
Packages
❱
Built-in Packages
Create Custom Packages
Create Packages as Crates
External Packages
❱
Random Number Generation, Shuffling and Sampling
Scripting Language
Comments
❱
Doc-Comments
Values and Types
❱
Dynamic Values
❱
type_of()
Value Tag
Serialization/Deserialization with serde
Numbers
❱
Operators
Standard Functions
Value Conversions
Ranges
Bit-Fields
Strings and Characters
❱
ImmutableString
Standard Functions and Operators
Arrays
❱
BLOB's (Byte Arrays)
Object Maps
❱
Parse from JSON
Special Support for OOP
Timestamps
Keywords
Statements
❱
Statement Expression
Variables
❱
Variable Shadowing
Strict Variables Mode
Variable Definition Filter
Variable Resolver
Constants
❱
Automatic Global Module
Assignments
Compound Assignments
Logic Operators
In Operator
If Statement
❱
If Expression
Switch Statement
❱
Switch Expression
While Loop
Do Loop
Loop Statement
For Loop
❱
Make a Custom Type Iterable
Return Value
Throw Exception on Error
Catch Exceptions
Functions
❱
Method Calls
Overloading
Namespaces
Function Pointers
❱
Currying
Anonymous Functions
Closures
Metadata
❱
Get Scripted Functions Metadata in Rhai
Get Scripted Functions Metadata from AST
Get Native Function Signatures
Export All Functions Metadata to JSON
Print and Debug
Modules
❱
Export Variables, Functions and Sub-Modules from Script
Import Modules
Eval Function
Safety and Protection
Introduction
Sand-Boxing
Limits
❱
Maximum Length of Strings
Maximum Size of Arrays
Maximum Size of Object Maps
Maximum Number of Operations
❱
Tracking Progress and Force-Termination
Maximum Number of Modules
Maximum Call Stack Depth
Maximum Expression Depth
Turn Off Safety Checks
Script Optimization
Introduction
Optimization Passes
❱
Dead Code Elimination
Constants Propagation
Compound Assignment Rewrite
Eager Operator Evaluation
Re-Optimize an AST
Subtle Semantic Changes
Eager Function Evaluation
❱
Side-Effect Considerations
Volatility Considerations
Advanced Topics
Manage AST's
Low-Level API to Register Functions
Evaluation Context
Call Function Within Caller's Scope
Use Rhai as a DSL
❱
Remap Tokens During Parsing
Disable Keywords and/or Operators
Disable Looping
Custom Operators
Extend with Custom Syntax
Debugging Interface
❱
Debugger
❱
State
Call Stack
Break-Points
Debugging Server
Usage Patterns
Programming Styles
❱
Object-Oriented Programming (OOP)
Working with Rust Enums
Simulate Macros to Simplify Scripts
Working with Constants
❱
Dynamic Constants Provider
Global Constants
Loadable Configuration
Multi-Layered Functions
Hot Reloading
One Engine Instance Per Call
Multi-Threaded Synchronization
Designing a Scriptable API
❱
Control Layer Over Rust Backend
Singleton Command Object
Blocking/Async Function Calls
Scriptable Event Handler with State
❱
Main Style
JS Style
Map Style
Domain-Specific Tools
Multiple Instantiation
Language Reference
Introduction
Comments
Value Types
❱
Dynamic Values
❱
type_of()
Value Tag
Numbers
❱
Operators
Standard Functions
Value Conversions
Ranges
Bit-Fields
Strings and Characters
❱
Standard Functions and Operators
Arrays
❱
BLOB's (Byte Arrays)
Object Maps
❱
Special Support for OOP
Timestamps
Keywords
Statements
Variables
Constants
❱
Automatic Global Module
Assignments
Operators
Conditional Statements
❱
If Statement
Switch Statement
Loops
❱
While Loop
Do Loop
Infinite Loop
For Loop
Return Value
Throw Exception on Error
❱
Catch Exceptions
Functions
❱
Method Calls
Overloading
Function Pointers
❱
Currying
Anonymous Functions
Closures
Metadata
Print and Debug
Modules
❱
Export Variables, Functions and Sub-Modules from Script
Import Modules
Eval Function
Appendix
External Tools
❱
Online Playground
rhai-doc
Keywords
Operators and Symbols
Literals
Light (default)
Rust
Coal
Navy
Ayu
Rhai - Embedded Scripting for Rust
Rhai Language Reference
This is a stand-alone reference for the Rhai scripting language.
