Trait Host 

pub trait Host {
    // Provided methods
    fn write_stdout(&mut self, _bytes: &[u8]) { ... }
    fn write_stderr(&mut self, _bytes: &[u8]) { ... }
    fn exit_code(&self) -> i32 { ... }
    fn set_exit_code(&mut self, _exit_code: i32) { ... }
    fn argv(&self) -> &[String] { ... }
    fn env(&self, _name: &str) -> Option<&str> { ... }
    fn set_env(&mut self, _name: &str, _value: &str) { ... }
    fn delete_env(&mut self, _name: &str) -> bool { ... }
    fn now_ms(&mut self) -> u64 { ... }
    fn monotonic_ns(&mut self) -> u64 { ... }
    fn random(&mut self) -> f64 { ... }
    fn hash(&mut self, _algorithm: &str, _data: &[u8]) -> Option<Vec<u8>> { ... }
    fn script_compiler(
        &mut self,
    ) -> Option<&mut (dyn CompileProvider + 'static)> { ... }
    fn timers(&mut self) -> Option<&mut (dyn TimerProvider + 'static)> { ... }
}

External capabilities available to the JavaScript runtime.

Runtime values never cross this boundary. The engine owns all JavaScript objects and value semantics; hosts provide byte sinks and process services.

Provided Methods

fn write_stdout(&mut self, _bytes: &[u8])

fn write_stderr(&mut self, _bytes: &[u8])

fn exit_code(&self) -> i32

fn set_exit_code(&mut self, _exit_code: i32)

fn argv(&self) -> &[String]

fn env(&self, _name: &str) -> Option<&str>

fn set_env(&mut self, _name: &str, _value: &str)

fn delete_env(&mut self, _name: &str) -> bool

fn now_ms(&mut self) -> u64

fn monotonic_ns(&mut self) -> u64

fn random(&mut self) -> f64

fn hash(&mut self, _algorithm: &str, _data: &[u8]) -> Option<Vec<u8>>

fn script_compiler(&mut self) -> Option<&mut (dyn CompileProvider + 'static)>

This host’s script compiler, or None when it provides none.

Presence MUST remain stable for the lifetime of one machine because it determines whether node:vm is installed during construction.

fn timers(&mut self) -> Option<&mut (dyn TimerProvider + 'static)>

This host’s timer scheduler, or None when it provides none.

Presence MUST remain stable for the lifetime of one machine because it determines whether setTimeout/clearTimeout are installed during construction.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors