Struct SystemHost 

pub struct SystemHost;

A default host over the process: its streams, the system clock, UTC. The default host: the process’s streams, the system clock, UTC.

Trait Implementations

impl Debug for SystemHost

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

Formats the value using the given formatter.

impl Default for SystemHost

fn default() -> SystemHost

Returns the “default value” for a type.

impl Host for SystemHost

fn write(&mut self, stream: Stream, text: &[u8])

Writes host output (print): UTF-8, with a lone surrogate of the JavaScript string encoded as is (WTF-8), as QuickJS’s JS_ToCStringLen writes it. The default writes to the process’s streams.

fn now_ms(&mut self) -> f64

Milliseconds since the Unix epoch (Date.now()).

fn local_tz_offset_minutes(&mut self, _utc_ms: f64) -> i32

UTC minus local time, in minutes, at utc_ms (Date.prototype.getTimezoneOffset’s sign). The default is UTC.

fn random_seed(&mut self) -> u64

The initial state of Math.random. The default derives it from the system clock, as QuickJS seeds from host time.

fn promise_rejection(&mut self, event: RejectionEvent, promise: Value)

HostPromiseRejectionTracker(promise, operation). The promise is a value of the runtime; while rejection tracking is on (Runtime::set_track_rejections) the runtime also keeps every unhandled rejected promise alive in Runtime::unhandled_rejections. The default ignores the event.

fn read_file(&mut self, path: &str) -> Option<String>

The text of the file at path, for the CLI’s load and read (qjs --std). The default reads the process’s file system.

fn interrupt(&mut self) -> bool

Polled about every thousand loop back-edges and calls while a script runs: true stops the script with an uncatchable InternalError: interrupted. The default never interrupts.