Crate v8

A high-level wrapper around the V8 Javascript engine.

Usage

First, you need to create an Isolate. An isolate is a VM instance with its own heap. You should most likely create one per thread and re-use it as much as possible.

Then, you need to create a Context. A context is an execution environment that allows separate, unrelated, JavaScript code to run in a single instance of V8. You must explicitly specify the context in which you want any JavaScript code to be run. You should keep track of the context of a script manually as part of your application.

Example

use v8::{self, value};

// Create a V8 heap
let isolate = v8::Isolate::new();
// Create a new context of execution
let context = v8::Context::new(&isolate);

// Load the source code that we want to evaluate
let source = value::String::from_str(&isolate, "'Hello, ' + 'World!'");

// Compile the source code.  `unwrap()` panics if the code is invalid,
// e.g. if there is a syntax  error.
let script = v8::Script::compile(&isolate, &context, &source).unwrap();

// Run the compiled script.  `unwrap()` panics if the code threw an
// exception.
let result = script.run(&context).unwrap();

// Convert the result to a value::String.
let result_str = result.to_string(&context);

// Success!
assert_eq!("Hello, World!", result_str.value());

Isolate foreground tasks

Javascript can produce "deferred" or "time-outed" tasks that need to run on the main thread. Additionally, V8 has a bunch of internal tasks it wants to perform regularly (for example GC). The user should therefore call isolate.run_enqueued_tasks() regularly to allow these tasks to run.

Reexports

pub use context::Context;

pub use isolate::Isolate;

pub use script::Script;

pub use value::Value;

Modules

context	Execution contexts and sandboxing.
error	Error types and utilities.
isolate	Heap and execution isolation.
script	Script and source code compilation, execution, origins and management.
template	Templates for constructing functions and objects efficiently.
value	Javascript values that user code can interact with.