Trait Js 

pub trait Js: Sealed {
    // Required methods
    fn eval(&mut self, source: &str) -> JsResult<Value>;
    fn eval_bytes(&mut self, source: &[u8]) -> JsResult<Value>;
    fn eval_with_filename(
        &mut self,
        source: &str,
        filename: &str,
    ) -> JsResult<Value>;
    fn eval_with_options(
        &mut self,
        source: &str,
        options: &EvalOptions,
    ) -> JsResult<Value>;
    fn eval_bytes_with_options(
        &mut self,
        source: &[u8],
        options: &EvalOptions,
    ) -> JsResult<Value>;
    fn eval_bytes_with_filename(
        &mut self,
        source: &[u8],
        filename: &str,
    ) -> JsResult<Value>;
    fn compile(&mut self, source: &str) -> JsResult<FunctionBytecodeRef>;
    fn compile_bytes(&mut self, source: &[u8]) -> JsResult<FunctionBytecodeRef>;
    fn compile_with_filename(
        &mut self,
        source: &str,
        filename: &str,
    ) -> JsResult<FunctionBytecodeRef>;
    fn compile_with_options(
        &mut self,
        source: &str,
        options: &CompileOptions,
    ) -> JsResult<FunctionBytecodeRef>;
    fn compile_bytes_with_options(
        &mut self,
        source: &[u8],
        options: &CompileOptions,
    ) -> JsResult<FunctionBytecodeRef>;
    fn compile_bytes_with_filename(
        &mut self,
        source: &[u8],
        filename: &str,
    ) -> JsResult<FunctionBytecodeRef>;
    fn execute(&mut self, script: &FunctionBytecodeRef) -> JsResult<Value>;
    fn compile_module(&mut self, source: &str) -> JsResult<ModuleBytecodeRef>;
    fn compile_module_bytes(
        &mut self,
        source: &[u8],
    ) -> JsResult<ModuleBytecodeRef>;
    fn compile_module_with_filename(
        &mut self,
        source: &str,
        filename: &str,
    ) -> JsResult<ModuleBytecodeRef>;
    fn compile_module_bytes_with_options(
        &mut self,
        source: &[u8],
        options: &CompileOptions,
    ) -> JsResult<ModuleBytecodeRef>;
    fn compile_module_bytes_with_filename(
        &mut self,
        source: &[u8],
        filename: &str,
    ) -> JsResult<ModuleBytecodeRef>;
    fn compile_module_bytes_with_import_meta(
        &mut self,
        source: &[u8],
        filename: &str,
        import_meta: Vec<(String, Value)>,
    ) -> JsResult<ModuleBytecodeRef>;
    fn execute_module(&mut self, module: &ModuleBytecodeRef) -> JsResult<Value>;
    fn call(
        &mut self,
        callable: &CallableRef,
        this_value: Value,
        arguments: &[Value],
    ) -> JsResult<Value>;
    fn construct(
        &mut self,
        constructor: &CallableRef,
        arguments: &[Value],
    ) -> JsResult<Value>;
    fn construct_with_new_target(
        &mut self,
        constructor: &CallableRef,
        new_target: &CallableRef,
        arguments: &[Value],
    ) -> JsResult<Value>;
    fn new_object(&mut self) -> JsResult<ObjectRef>;
    fn new_object_with_prototype(
        &mut self,
        prototype: Option<&ObjectRef>,
    ) -> JsResult<ObjectRef>;
    fn new_array(&mut self) -> JsResult<ObjectRef>;
    fn new_array_from_values(
        &mut self,
        values: Vec<Value>,
    ) -> JsResult<ObjectRef>;
    fn get_own_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
    ) -> JsResult<Option<CompleteOrdinaryPropertyDescriptor>>;
    fn define_own_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
        descriptor: &OrdinaryPropertyDescriptor,
    ) -> JsResult<bool>;
    fn get_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
    ) -> JsResult<Value>;
    fn get_property_with_receiver(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
        receiver: Value,
    ) -> JsResult<Value>;
    fn set_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
        value: Value,
    ) -> JsResult<bool>;
    fn set_property_with_receiver(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
        value: Value,
        receiver: Value,
    ) -> JsResult<bool>;
    fn delete_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
    ) -> JsResult<bool>;
    fn has_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
    ) -> JsResult<bool>;
    fn has_own_property(
        &mut self,
        object: &ObjectRef,
        key: &PropertyKey,
    ) -> JsResult<bool>;
    fn own_property_keys(
        &mut self,
        object: &ObjectRef,
    ) -> JsResult<Vec<PropertyKey>>;
    fn get_prototype_of(
        &mut self,
        object: &ObjectRef,
    ) -> JsResult<Option<ObjectRef>>;
    fn set_prototype_of(
        &mut self,
        object: &ObjectRef,
        prototype: Option<&ObjectRef>,
    ) -> JsResult<bool>;
    fn as_callable(
        &mut self,
        object: &ObjectRef,
    ) -> JsResult<Option<CallableRef>>;
    fn is_constructor(&mut self, object: &ObjectRef) -> JsResult<bool>;
    fn is_array_object(&mut self, object: &ObjectRef) -> JsResult<bool>;
    fn is_error_object(&mut self, object: &ObjectRef) -> JsResult<bool>;
    fn to_js_string(&mut self, value: &Value) -> JsResult<JsString>;
    fn to_number(&mut self, value: &Value) -> JsResult<f64>;
    fn detach_array_buffer(&mut self, value: &Value) -> JsResult<()>;
    fn type_of(&mut self, value: &Value) -> JsResult<String>;
    fn print_value(&mut self, value: &Value) -> JsResult<String>;
    fn qjs_print_value_bytes(&mut self, value: &Value) -> JsResult<Vec<u8>>;
    fn new_symbol(
        &mut self,
        description: Option<JsString>,
    ) -> JsResult<SymbolRef>;
    fn symbol_description(
        &mut self,
        symbol: &SymbolRef,
    ) -> JsResult<Option<JsString>>;
    fn well_known_symbol(
        &mut self,
        symbol: WellKnownSymbol,
    ) -> JsResult<SymbolRef>;
    fn promise_snapshot(
        &mut self,
        promise: &ObjectRef,
    ) -> JsResult<Option<PromiseSnapshot>>;
    fn new_promise(&mut self) -> JsResult<PromiseCapability>;
    fn promise_then(
        &mut self,
        promise: &ObjectRef,
        on_fulfilled: impl HostFunction<Raw>,
        on_rejected: impl HostFunction<Raw>,
    ) -> JsResult<ObjectRef>;
    fn new_array_buffer(&mut self, bytes: &[u8]) -> JsResult<ObjectRef>;
    fn array_buffer_len(
        &mut self,
        buffer: &ObjectRef,
    ) -> JsResult<Option<usize>>;
    fn array_buffer_to_vec(&mut self, buffer: &ObjectRef) -> JsResult<Vec<u8>>;
    fn with_array_buffer_bytes<R>(
        &mut self,
        buffer: &ObjectRef,
        f: impl FnOnce(&[u8]) -> R,
    ) -> JsResult<R>;
    fn write_array_buffer(
        &mut self,
        buffer: &ObjectRef,
        offset: usize,
        data: &[u8],
    ) -> JsResult<()>;
    fn typed_array_view(
        &mut self,
        array: &ObjectRef,
    ) -> JsResult<Option<TypedArrayView>>;
    fn new_typed_array(
        &mut self,
        kind: TypedArrayKind,
        buffer: &ObjectRef,
        byte_offset: usize,
        length: Option<usize>,
    ) -> JsResult<ObjectRef>;
    fn global_object(&mut self) -> JsResult<ObjectRef>;
    fn object_prototype(&mut self) -> JsResult<ObjectRef>;
    fn array_prototype(&mut self) -> JsResult<ObjectRef>;
    fn function_prototype(&mut self) -> JsResult<ObjectRef>;
    fn iterator_prototype(&mut self) -> JsResult<ObjectRef>;
    fn string_iterator_prototype(&mut self) -> JsResult<ObjectRef>;
    fn number_prototype(&mut self) -> JsResult<ObjectRef>;
    fn boolean_prototype(&mut self) -> JsResult<ObjectRef>;
    fn string_prototype(&mut self) -> JsResult<ObjectRef>;
    fn symbol_prototype(&mut self) -> JsResult<ObjectRef>;
    fn bigint_prototype(&mut self) -> JsResult<ObjectRef>;
    fn function_constructor(&mut self) -> JsResult<CallableRef>;
    fn new_native_error(
        &mut self,
        kind: NativeErrorKind,
        message: &str,
    ) -> JsResult<Value>;
    fn install_qjs_helpers(&mut self, helpers: &QjsHelpers) -> JsResult<()>;
    fn new_function<Args>(
        &mut self,
        options: FunctionOptions,
        function: impl HostFunction<Args>,
    ) -> JsResult<CallableRef>;
    fn define_function<Args>(
        &mut self,
        target: &ObjectRef,
        name: &str,
        length: u32,
        function: impl HostFunction<Args>,
    ) -> JsResult<CallableRef>;
    fn new_host_object<T: 'static>(
        &mut self,
        value: T,
        prototype: Option<&ObjectRef>,
    ) -> JsResult<ObjectRef>;
    fn host_data<T: 'static>(
        &mut self,
        object: &ObjectRef,
    ) -> JsResult<Option<Rc<T>>>;
    fn throw_error(
        &mut self,
        kind: NativeErrorKind,
        message: &str,
    ) -> RuntimeError;
}

The operations Context and a host function’s Scope share, for code generic over where it runs. Sealed; both types also have each as an inherent method, so calling one needs no import.

Required Methods

fn eval(&mut self, source: &str) -> JsResult<Value>

Compiles and runs source as a script; the completion value.

fn eval_bytes(&mut self, source: &[u8]) -> JsResult<Value>

fn eval_with_filename( &mut self, source: &str, filename: &str, ) -> JsResult<Value>

fn eval_with_options( &mut self, source: &str, options: &EvalOptions, ) -> JsResult<Value>

fn eval_bytes_with_options( &mut self, source: &[u8], options: &EvalOptions, ) -> JsResult<Value>

fn eval_bytes_with_filename( &mut self, source: &[u8], filename: &str, ) -> JsResult<Value>

Compiles and runs source as a script named filename; the completion value. A syntax error is thrown (RuntimeError::Exception with a SyntaxError), as QuickJS’s JS_Eval does.

fn compile(&mut self, source: &str) -> JsResult<FunctionBytecodeRef>

fn compile_bytes(&mut self, source: &[u8]) -> JsResult<FunctionBytecodeRef>

fn compile_with_filename( &mut self, source: &str, filename: &str, ) -> JsResult<FunctionBytecodeRef>

fn compile_with_options( &mut self, source: &str, options: &CompileOptions, ) -> JsResult<FunctionBytecodeRef>

fn compile_bytes_with_options( &mut self, source: &[u8], options: &CompileOptions, ) -> JsResult<FunctionBytecodeRef>

fn compile_bytes_with_filename( &mut self, source: &[u8], filename: &str, ) -> JsResult<FunctionBytecodeRef>

Compiles source as a script named filename. A syntax error is thrown (RuntimeError::Exception with a SyntaxError). Inside a host function the code is transient whatever the options say.

fn execute(&mut self, script: &FunctionBytecodeRef) -> JsResult<Value>

Runs a compiled script with the global object as this.

fn compile_module(&mut self, source: &str) -> JsResult<ModuleBytecodeRef>

fn compile_module_bytes(&mut self, source: &[u8]) -> JsResult<ModuleBytecodeRef>

fn compile_module_with_filename( &mut self, source: &str, filename: &str, ) -> JsResult<ModuleBytecodeRef>

fn compile_module_bytes_with_options( &mut self, source: &[u8], options: &CompileOptions, ) -> JsResult<ModuleBytecodeRef>

fn compile_module_bytes_with_filename( &mut self, source: &[u8], filename: &str, ) -> JsResult<ModuleBytecodeRef>

fn compile_module_bytes_with_import_meta( &mut self, source: &[u8], filename: &str, import_meta: Vec<(String, Value)>, ) -> JsResult<ModuleBytecodeRef>

Compiles source as the module filename, whose import.meta starts with import_meta (qjs’s url and main). A syntax error is thrown.

fn execute_module(&mut self, module: &ModuleBytecodeRef) -> JsResult<Value>

Links and evaluates a compiled module and what it imports; the promise of its evaluation.

fn call( &mut self, callable: &CallableRef, this_value: Value, arguments: &[Value], ) -> JsResult<Value>

fn construct( &mut self, constructor: &CallableRef, arguments: &[Value], ) -> JsResult<Value>

fn construct_with_new_target( &mut self, constructor: &CallableRef, new_target: &CallableRef, arguments: &[Value], ) -> JsResult<Value>

fn new_object(&mut self) -> JsResult<ObjectRef>

fn new_object_with_prototype( &mut self, prototype: Option<&ObjectRef>, ) -> JsResult<ObjectRef>

fn new_array(&mut self) -> JsResult<ObjectRef>

fn new_array_from_values(&mut self, values: Vec<Value>) -> JsResult<ObjectRef>

fn get_own_property( &mut self, object: &ObjectRef, key: &PropertyKey, ) -> JsResult<Option<CompleteOrdinaryPropertyDescriptor>>

fn define_own_property( &mut self, object: &ObjectRef, key: &PropertyKey, descriptor: &OrdinaryPropertyDescriptor, ) -> JsResult<bool>

fn get_property( &mut self, object: &ObjectRef, key: &PropertyKey, ) -> JsResult<Value>

fn get_property_with_receiver( &mut self, object: &ObjectRef, key: &PropertyKey, receiver: Value, ) -> JsResult<Value>

fn set_property( &mut self, object: &ObjectRef, key: &PropertyKey, value: Value, ) -> JsResult<bool>

fn set_property_with_receiver( &mut self, object: &ObjectRef, key: &PropertyKey, value: Value, receiver: Value, ) -> JsResult<bool>

fn delete_property( &mut self, object: &ObjectRef, key: &PropertyKey, ) -> JsResult<bool>

fn has_property( &mut self, object: &ObjectRef, key: &PropertyKey, ) -> JsResult<bool>

fn has_own_property( &mut self, object: &ObjectRef, key: &PropertyKey, ) -> JsResult<bool>

fn own_property_keys( &mut self, object: &ObjectRef, ) -> JsResult<Vec<PropertyKey>>

fn get_prototype_of( &mut self, object: &ObjectRef, ) -> JsResult<Option<ObjectRef>>

fn set_prototype_of( &mut self, object: &ObjectRef, prototype: Option<&ObjectRef>, ) -> JsResult<bool>

fn as_callable(&mut self, object: &ObjectRef) -> JsResult<Option<CallableRef>>

The object as a callable reference; None when it is not callable.

fn is_constructor(&mut self, object: &ObjectRef) -> JsResult<bool>

fn is_array_object(&mut self, object: &ObjectRef) -> JsResult<bool>

IsArray.

fn is_error_object(&mut self, object: &ObjectRef) -> JsResult<bool>

fn to_js_string(&mut self, value: &Value) -> JsResult<JsString>

ToString(value).

fn to_number(&mut self, value: &Value) -> JsResult<f64>

ToNumber(value).

fn detach_array_buffer(&mut self, value: &Value) -> JsResult<()>

QuickJS’s JS_DetachArrayBuffer: detaches an ArrayBuffer; anything else is ignored.

fn type_of(&mut self, value: &Value) -> JsResult<String>

typeof value.

fn print_value(&mut self, value: &Value) -> JsResult<String>

QuickJS’s JS_PrintValue: what print and an uncaught-exception dump show. Runs no JavaScript (no accessor, trap or coercion).

fn qjs_print_value_bytes(&mut self, value: &Value) -> JsResult<Vec<u8>>

print_value as the bytes QuickJS writes: a lone surrogate of a raw name, message or stack as its own three bytes (WTF-8) instead of U+FFFD.

fn new_symbol(&mut self, description: Option<JsString>) -> JsResult<SymbolRef>

fn symbol_description( &mut self, symbol: &SymbolRef, ) -> JsResult<Option<JsString>>

fn well_known_symbol(&mut self, symbol: WellKnownSymbol) -> JsResult<SymbolRef>

fn promise_snapshot( &mut self, promise: &ObjectRef, ) -> JsResult<Option<PromiseSnapshot>>

A promise’s state and result; None when promise is not one.

fn new_promise(&mut self) -> JsResult<PromiseCapability>

NewPromiseCapability(%Promise%): a pending promise and its resolving functions.

fn promise_then( &mut self, promise: &ObjectRef, on_fulfilled: impl HostFunction<Raw>, on_rejected: impl HostFunction<Raw>, ) -> JsResult<ObjectRef>

promise.then(on_fulfilled, on_rejected) with host functions; the promise then returns.

fn new_array_buffer(&mut self, bytes: &[u8]) -> JsResult<ObjectRef>

A new ArrayBuffer holding a copy of bytes.

fn array_buffer_len(&mut self, buffer: &ObjectRef) -> JsResult<Option<usize>>

A buffer’s length in bytes; None for a detached buffer or another object.

fn array_buffer_to_vec(&mut self, buffer: &ObjectRef) -> JsResult<Vec<u8>>

A copy of a buffer’s bytes (ArrayBuffer or SharedArrayBuffer); a detached buffer or another object throws a TypeError.

fn with_array_buffer_bytes<R>( &mut self, buffer: &ObjectRef, f: impl FnOnce(&[u8]) -> R, ) -> JsResult<R>

Calls f with a buffer’s bytes, borrowed in place for an ArrayBuffer and copied first for a SharedArrayBuffer. f runs inside the engine’s borrow, so it cannot call the engine.

fn write_array_buffer( &mut self, buffer: &ObjectRef, offset: usize, data: &[u8], ) -> JsResult<()>

Writes data into a buffer at offset: a TypeError for a detached buffer or another object, a RangeError past its end.

fn typed_array_view( &mut self, array: &ObjectRef, ) -> JsResult<Option<TypedArrayView>>

A typed array’s kind, buffer, byte offset and current length; None for anything but a typed array (a DataView included).

fn new_typed_array( &mut self, kind: TypedArrayKind, buffer: &ObjectRef, byte_offset: usize, length: Option<usize>, ) -> JsResult<ObjectRef>

new <Kind>Array(buffer, byte_offset, length); without length the view tracks a resizable buffer’s length.

fn global_object(&mut self) -> JsResult<ObjectRef>

fn object_prototype(&mut self) -> JsResult<ObjectRef>

fn array_prototype(&mut self) -> JsResult<ObjectRef>

fn function_prototype(&mut self) -> JsResult<ObjectRef>

fn iterator_prototype(&mut self) -> JsResult<ObjectRef>

fn string_iterator_prototype(&mut self) -> JsResult<ObjectRef>

fn number_prototype(&mut self) -> JsResult<ObjectRef>

fn boolean_prototype(&mut self) -> JsResult<ObjectRef>

fn string_prototype(&mut self) -> JsResult<ObjectRef>

fn symbol_prototype(&mut self) -> JsResult<ObjectRef>

fn bigint_prototype(&mut self) -> JsResult<ObjectRef>

fn function_constructor(&mut self) -> JsResult<CallableRef>

fn new_native_error( &mut self, kind: NativeErrorKind, message: &str, ) -> JsResult<Value>

A new native error object (not thrown).

fn install_qjs_helpers(&mut self, helpers: &QjsHelpers) -> JsResult<()>

qjs’s print and console.log, scriptArgs, and under std its load and read.

fn new_function<Args>( &mut self, options: FunctionOptions, function: impl HostFunction<Args>, ) -> JsResult<CallableRef>

A function whose body is function: a closure over a Scope (|scope: &mut Scope<'_>| …), named and shaped by options.

fn define_function<Args>( &mut self, target: &ObjectRef, name: &str, length: u32, function: impl HostFunction<Args>, ) -> JsResult<CallableRef>

Js::new_function defined on target as name, writable and configurable, not enumerable, as QuickJS’s JS_SetPropertyFunctionList defines a method.

fn new_host_object<T: 'static>( &mut self, value: T, prototype: Option<&ObjectRef>, ) -> JsResult<ObjectRef>

An object inheriting from prototype (None for null) holding value, which drops when the object is collected.

fn host_data<T: 'static>( &mut self, object: &ObjectRef, ) -> JsResult<Option<Rc<T>>>

The value a host object holds; None for an ordinary object or a value of another type.

fn throw_error(&mut self, kind: NativeErrorKind, message: &str) -> RuntimeError

An error object of kind with message and a stack from the running frames, as the error to return: return Err(js.throw_error(NativeErrorKind::Type, "x is required")).

Dyn Compatibility

This trait is not dyn compatible.

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

Implementors

impl Js for Context

impl Js for Scope<'_>