dowdiness/js_engine/interpreter

dowdiness/js_engine/interpreter does not have a README file

JsException

pub suberror JsException {
  JsException(Value)
}

ArrayData

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pub(all) struct ArrayData {
  elements : Array[Value]
}

Binding

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type Binding

BindingKind

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pub(all) enum BindingKind {
  LetBinding
  ConstBinding
  VarBinding
}

impl Eq for BindingKind

impl Show for BindingKind

Callable

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pub(all) enum Callable {
  UserFunc(FuncData)
  ArrowFunc(FuncData)
  UserFuncExt(FuncDataExt)
  ArrowFuncExt(FuncDataExt)
  NativeCallable(String, (Array[Value]) -> Value raise)
  NonConstructableCallable(String, (Array[Value]) -> Value raise)
  BoundFunc(Value, Value, Array[Value])
  FuncCallMethod(Value)
  FuncApplyMethod(Value)
  MethodCallable(String, (Value, Array[Value]) -> Value raise)
  InterpreterCallable(String, (Interpreter, Value, Array[Value]) -> Value raise)
  ConstructorOnlyCallable(String, (Interpreter, Array[Value]) -> Value raise)
  ClassConstructor(String, Value, Value?, (Array[String], Array[@dowdiness/js_engine/ast.Stmt
Stmt])?, Environment, Value)
}

Environment

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pub(all) struct Environment {
  bindings : Map[String, Binding]
  parent : Environment?
}

Environment::assign

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fn Environment::assign(self : Environment, name : String, value : Value) -> Unit raise

Environment::def

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fn Environment::def(self : Environment, name : String, value : Value, kind : BindingKind) -> Unit raise

Environment::def_builtin

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fn Environment::def_builtin(self : Environment, name : String, value : Value) -> Unit

Environment::def_tdz

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fn Environment::def_tdz(self : Environment, name : String, kind : BindingKind) -> Unit raise

Define a TDZ binding (let/const before initialization)

Environment::get

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fn Environment::get(self : Environment, name : String) -> Value raise

Environment::has

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fn Environment::has(self : Environment, name : String) -> Bool

Environment::initialize

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fn Environment::initialize(self : Environment, name : String, value : Value) -> Unit raise

Initialize a TDZ binding (when declaration is executed)

Environment::new

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fn Environment::new(parent? : Environment?) -> Environment

FuncData

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pub(all) struct FuncData {
  name : String?
  params : Array[String]
  body : Array[@dowdiness/js_engine/ast.Stmt
Stmt]
  closure : Environment
}

FuncDataExt

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pub(all) struct FuncDataExt {
  name : String?
  params : Array[@dowdiness/js_engine/ast.Param
Param]
  rest_param : String?
  body : Array[@dowdiness/js_engine/ast.Stmt
Stmt]
  closure : Environment
}

Interpreter

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pub(all) struct Interpreter {
  output : Array[String]
  global : Environment
  global_this : Value
  strict : Bool
  microtask_queue : Array[Microtask]
  timer_queue : Array[TimerTask]
  timer_id_counter : Ref[Int]
  timer_insertion_counter : Ref[Int]
  cancelled_timer_ids : Map[Int, Bool]
}

Interpreter::enqueue_microtask

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fn Interpreter::enqueue_microtask(self : Interpreter, callback : Value, args : Array[Value]) -> Unit

Enqueue a microtask to be executed when the current execution context completes This implements HostEnqueuePromiseJob from the ECMAScript spec

Interpreter::new

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fn Interpreter::new() -> Interpreter

Interpreter::run

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fn Interpreter::run(self : Interpreter, stmts : Array[@dowdiness/js_engine/ast.Stmt
Stmt]) -> Value raise

Interpreter::run_microtasks

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fn Interpreter::run_microtasks(self : Interpreter) -> Unit raise

Run all pending microtasks until the queue is empty This is called after each task (script execution) completes Implements the microtask checkpoint from WHATWG Event Loop spec

Interpreter::run_timers

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fn Interpreter::run_timers(self : Interpreter) -> Unit raise

Run the event loop: process all pending timer tasks with microtask checkpoints between each (per WHATWG event loop spec). Timers are sorted by (delay, insertion_order) so they fire in the correct relative order. After each timer callback, microtasks are drained before the next timer fires.

For setInterval, the timer is re-enqueued after each invocation until cancelled. A safety limit prevents infinite loops.

MapData

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pub(all) struct MapData {
  entries : Array[(Value, Value)]
}

Map data structure - stores key-value pairs with insertion order preservation Uses SameValueZero for key comparison (NaN === NaN, +0 === -0)

Microtask

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pub(all) struct Microtask {
  callback : Value
  args : Array[Value]
}

Microtask record for the event loop microtask queue Stores a callback function and argument list to pass to it

ObjectData

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pub(all) struct ObjectData {
  properties : Map[String, Value]
  symbol_properties : Map[Int, Value]
  prototype : Value
  callable : Callable?
  class_name : String
  descriptors : Map[String, PropDescriptor]
  symbol_descriptors : Map[Int, PropDescriptor]
  extensible : Bool
}

PromiseData

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pub(all) struct PromiseData {
  state : PromiseState
  result : Value
  fulfill_reactions : Array[PromiseReaction]
  reject_reactions : Array[PromiseReaction]
  is_handled : Bool
  properties : Map[String, Value]
  symbol_properties : Map[Int, Value]
}

Promise data structure per ECMAScript spec Promises have a state, result value, and queues of pending reactions

PromiseReaction

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pub(all) struct PromiseReaction {
  handler : Value?
  resolve : Value
  reject : Value
  reaction_type : PromiseReactionType
}

Promise reaction record - stores callbacks for promise resolution Each reaction contains the handler (onFulfilled or onRejected) and the dependent promise's resolve/reject capabilities

PromiseReactionType

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pub(all) enum PromiseReactionType {
  Fulfill
  Reject
}

PromiseState

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pub(all) enum PromiseState {
  Pending
  Fulfilled
  Rejected
}

Promise state per ECMAScript spec

PropDescriptor

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pub(all) struct PropDescriptor {
  writable : Bool
  enumerable : Bool
  configurable : Bool
}

RegexMatch

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type RegexMatch

SetData

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pub(all) struct SetData {
  values : Array[Value]
}

Set data structure - stores unique values with insertion order preservation Uses SameValueZero for value comparison (NaN === NaN, +0 === -0)

Signal

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pub(all) enum Signal {
  Normal(Value)
  ReturnSignal(Value)
  BreakSignal(String?)
  ContinueSignal(String?)
}

SymbolData

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pub(all) struct SymbolData {
  id : Int
  description : String?
}

Symbol data structure - each symbol has a unique ID and optional description

TimerTask

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pub(all) struct TimerTask {
  id : Int
  callback : Value
  args : Array[Value]
  delay : Int
  period : Int
  cancelled : Bool
  is_interval : Bool
  insertion_order : Int
}

Timer task for setTimeout/setInterval (task queue per WHATWG spec) Timers are processed one at a time with microtask checkpoints between each

Value

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pub(all) enum Value {
  Number(Double)
  String_(String)
  Bool(Bool)
  Null
  Undefined
  Object(ObjectData)
  Array(ArrayData)
  Symbol(SymbolData)
  Map(MapData)
  Set(SetData)
  Promise(PromiseData)
}

impl Show for Value

get_array_like_element

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fn get_array_like_element(val : Value, index : Int) -> Value

Get indexed element from array-like value

get_array_method

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fn get_array_method(data : ArrayData, prop : String) -> Value

get_array_method_with_interp

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fn get_array_method_with_interp(data : ArrayData, prop : String) -> Value

get_hasinstance_symbol

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fn get_hasinstance_symbol() -> SymbolData

Get the well-known Symbol.hasInstance

get_iterator_symbol

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fn get_iterator_symbol() -> SymbolData

Get the well-known Symbol.iterator

get_map_method

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fn get_map_method(_data : MapData, prop : String) -> Value

Get Map.prototype methods for a Map instance

get_number_method

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fn get_number_method(num_val : Value, prop : String) -> Value

get_promise_method

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fn get_promise_method(_data : PromiseData, prop : String) -> Value

Get Promise.prototype methods for a Promise instance

get_set_method

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fn get_set_method(_data : SetData, prop : String) -> Value

Get Set.prototype methods for a Set instance

get_string_method

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fn get_string_method(s : String, prop : String) -> Value

get_symbol_by_id

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fn get_symbol_by_id(id : Int) -> SymbolData?

Get a symbol by its ID

has_array_like_element

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fn has_array_like_element(val : Value, index : Int) -> Bool

Check if array-like value has indexed property

is_js_catchable_error

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fn is_js_catchable_error(err : Error) -> Bool

Check if an error is a JavaScript catchable error

is_truthy

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fn is_truthy(val : Value) -> Bool

js_error_to_throw_value

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fn js_error_to_throw_value(err : Error) -> Value

Convert a catchable error to the JS throw value used by this interpreter. Runtime engine errors are surfaced as strings like "TypeError: ...".

js_error_to_value

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fn js_error_to_value(err : Error) -> Value

Convert any catchable error to a JavaScript Error object Value

js_error_to_value_with_env

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fn js_error_to_value_with_env(err : Error, env : Environment?) -> Value

Convert any catchable error to a JavaScript Error object Value with proper prototype

make_array_iterator_value

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fn make_array_iterator_value(arr : ArrayData) -> Value

Create an array iterator object that iterates over array elements

make_func

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fn make_func(data : FuncData) -> Value

make_func_ext

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fn make_func_ext(data : FuncDataExt) -> Value

make_native_func

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fn make_native_func(name : String, func : (Array[Value]) -> Value raise) -> Value

make_object

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fn make_object(properties : Map[String, Value], prototype : Value, callable : Callable?, class_name : String, descriptors : Map[String, PropDescriptor], extensible : Bool) -> Value

Helper to create a basic object with default empty symbol maps

make_plain_object

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fn make_plain_object() -> Value

Helper to create a plain object

make_regexp_object

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fn make_regexp_object(pattern : String, flags : String) -> Value

make_string_iterator_value

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fn make_string_iterator_value(s : String) -> Value

Create a string iterator object that iterates over string characters Handles Unicode surrogate pairs correctly per ES6 spec

new_promise_data

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fn new_promise_data() -> PromiseData

Create a new pending promise data structure

new_symbol

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fn new_symbol(description : String?) -> SymbolData

Create a new symbol with a unique ID

regex_match_at

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fn regex_match_at(pattern : String, flags : String, input : String, start_pos : Int) -> RegexMatch? raise

regex_search

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fn regex_search(pattern : String, flags : String, input : String) -> RegexMatch? raise

regex_search_all

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fn regex_search_all(pattern : String, flags : String, input : String) -> Array[RegexMatch] raise

same_value

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fn same_value(a : Value, b : Value) -> Bool

same_value_zero

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fn same_value_zero(a : Value, b : Value) -> Bool

setup_builtins

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fn setup_builtins(env : Environment, output : Array[String]) -> Unit

setup_map_set_builtins

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fn setup_map_set_builtins(env : Environment) -> Unit

Setup Map and Set constructors and prototypes

setup_object_builtins

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fn setup_object_builtins(env : Environment) -> Unit

setup_promise

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fn setup_promise(env : Environment) -> Unit

Setup Promise constructor and prototype methods

setup_string_prototype

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fn setup_string_prototype(string_proto : Value) -> Unit

Populate String.prototype with all string methods

setup_timers

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fn setup_timers(env : Environment) -> Unit

Setup timer builtins: setTimeout, clearTimeout, setInterval, clearInterval These implement the WHATWG Timer APIs Reference: https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html#timers

strict_equal_val

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fn strict_equal_val(a : Value, b : Value) -> Bool

string_match_regex

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fn string_match_regex(s : String, pattern : String, flags : String) -> Value

string_replace_regex

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fn string_replace_regex(s : String, pattern : String, flags : String, replacement : String) -> Value

string_search_regex

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fn string_search_regex(s : String, pattern : String, flags : String) -> Value

this_to_string

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fn this_to_string(this_val : Value) -> String raise

Extract string from a this value (for String.prototype methods called via .call())

to_array_like_length

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fn to_array_like_length(val : Value) -> Int

ToLength: Get length from any value as per ECMAScript spec (array-like objects)

to_int32

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fn to_int32(n : Double) -> Int

to_number

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fn to_number(val : Value) -> Double raise

type_of

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fn type_of(val : Value) -> String

well_known_hasinstance_sym

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let well_known_hasinstance_sym : Ref[SymbolData?]

Well-known Symbol.hasInstance - stored globally for instanceof operator support

well_known_iterator_sym

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let well_known_iterator_sym : Ref[SymbolData?]

Well-known Symbol.iterator - stored globally for iterator protocol support

Source Files

Site source Report issue Packages Build queue Skills Statistics

#JsException

#ArrayData

#Binding

#BindingKind

#Callable

#Environment

#Environment::assign

#Environment::def

#Environment::def_builtin

#Environment::def_tdz

#Environment::get

#Environment::has

#Environment::initialize

#Environment::new

#FuncData

#FuncDataExt

#Interpreter

#Interpreter::enqueue_microtask

#Interpreter::new

#Interpreter::run

#Interpreter::run_microtasks

#Interpreter::run_timers

#MapData

#Microtask

#ObjectData

#PromiseData

#PromiseReaction

#PromiseReactionType

#PromiseState

#PropDescriptor

#RegexMatch

#SetData

#Signal

#SymbolData

#TimerTask

#Value

#get_array_like_element

#get_array_method

#get_array_method_with_interp

#get_hasinstance_symbol

#get_iterator_symbol

#get_map_method

#get_number_method

#get_promise_method

#get_set_method

#get_string_method

#get_symbol_by_id

#has_array_like_element

#is_js_catchable_error

#is_truthy

#js_error_to_throw_value

#js_error_to_value

#js_error_to_value_with_env

#make_array_iterator_value

#make_func

#make_func_ext

#make_native_func

#make_object

#make_plain_object

#make_regexp_object

#make_string_iterator_value

#new_promise_data

#new_symbol

#regex_match_at

#regex_search

#regex_search_all

#same_value

#same_value_zero

#setup_builtins

#setup_map_set_builtins

#setup_object_builtins

#setup_promise

#setup_string_prototype

#setup_timers

#strict_equal_val

#string_match_regex

#string_replace_regex

#string_search_regex

#this_to_string

#to_array_like_length

JsException

ArrayData

Binding

BindingKind

Callable

Environment

Environment::assign

Environment::def

Environment::def_builtin

Environment::def_tdz

Environment::get

Environment::has

Environment::initialize

Environment::new

FuncData

FuncDataExt

Interpreter

Interpreter::enqueue_microtask

Interpreter::new

Interpreter::run

Interpreter::run_microtasks

Interpreter::run_timers

MapData

Microtask

ObjectData

PromiseData

PromiseReaction

PromiseReactionType

PromiseState

PropDescriptor

RegexMatch

SetData

Signal

SymbolData

TimerTask

Value

get_array_like_element

get_array_method

get_array_method_with_interp

get_hasinstance_symbol

get_iterator_symbol

get_map_method

get_number_method

get_promise_method

get_set_method

get_string_method

get_symbol_by_id

has_array_like_element

is_js_catchable_error

is_truthy

js_error_to_throw_value

js_error_to_value

js_error_to_value_with_env

make_array_iterator_value

make_func

make_func_ext

make_native_func

make_object

make_plain_object

make_regexp_object

make_string_iterator_value

new_promise_data

new_symbol

regex_match_at

regex_search

regex_search_all

same_value

same_value_zero

setup_builtins

setup_map_set_builtins

setup_object_builtins

setup_promise

setup_string_prototype

setup_timers

strict_equal_val

string_match_regex

string_replace_regex

string_search_regex

this_to_string

to_array_like_length