Struct JsRuntime 

pub struct JsRuntime { /* private fields */ }

Available on crate features js and std only.

A javascript runtime, executing scripts on the current thread.

Create one via JsRuntime::builder, or use JsRuntime::eval_once for a one-off script evaluation with the default configuration.

A runtime is single-threaded (!Send); services which need to evaluate scripts from async (Send) contexts use a JsWorker instead.

Implementations

impl JsRuntime

pub fn builder() -> JsRuntimeBuilder

Create a JsRuntimeBuilder to configure a new runtime.

pub fn eval_once(src: impl AsRef<str>) -> Result<JsValue, JsError>

Evaluate a single script with the default runtime configuration, returning the value of its final expression.

pub fn eval(&mut self, src: impl AsRef<str>) -> Result<JsValue, JsError>

Evaluate a script, returning the value of its final expression.

State (globals, function definitions, …) persists across evaluations within the same runtime.

pub fn exec(&mut self, src: impl AsRef<str>) -> Result<(), JsError>

Execute a script while discarding its final expression value.

This avoids materializing a value snapshot when only script side effects are relevant.

pub fn call<I, V>( &mut self, name: impl AsRef<str>, args: I, ) -> Result<JsValue, JsError>

where I: IntoIterator<Item = V>, V: Into<JsValue>,

Call a global function (defined by a previously evaluated script, or registered as a host function) with the given arguments.

pub fn has_global_fn(&mut self, name: impl AsRef<str>) -> bool

Returns true if a global function with the given name exists.

pub fn is_poisoned(&self) -> bool

Returns true once an evaluation exceeded the configured execution time limit: the script was aborted mid-execution, so every later operation fails with JsErrorKind::Setup.

pub fn set_host_global<T>( &mut self, name: impl Into<JsStr>, object: JsHostObject<T>, ) -> Result<(), JsError>

where T: Send + 'static,

Install a Rust-owned native object as a global in this runtime.

This operation is deliberately runtime-local: native objects are not accepted by JsRuntimeBuilder, because a reusable builder may back multiple runtimes.

Trait Implementations

impl Debug for JsRuntime

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.