Skip to content

Commit

Permalink
Make iterator spec complaint (#1889)
Browse files Browse the repository at this point in the history 
This PR is also related to #577 

Changes:
- Implements `IteratorValue` (`IteratorResult::value()`)
- Implements `IteratorComplete` (`IteratorResult::complete()`)
- Implements `IteratorStep` (`IteratorRecord::step()`)
- Makes  `IteratorNext` (`IteratorRecord::next()`) spec compliant
- Deprecates/removes `JsValue::get_field()`.
  • Loading branch information
@HalidOdat
HalidOdat committed Mar 3, 2022
1 parent 00a1900 commit a9a82a7
Show file tree
Hide file tree
Showing 5 changed files with 164 additions and 100 deletions.
124 changes: 105 additions & 19 deletions boa_engine/src/builtins/iterable/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,8 @@ pub struct IteratorPrototypes {

impl IteratorPrototypes {
pub(crate) fn init(context: &mut Context) -> Self {
let _timer = Profiler::global().start_event("IteratorPrototypes::init", "init");

let iterator_prototype = create_iterator_prototype(context);
Self {
array_iterator: ArrayIterator::create_prototype(iterator_prototype.clone(), context),
Expand Down Expand Up @@ -77,7 +79,10 @@ impl IteratorPrototypes {
/// `CreateIterResultObject( value, done )`
///
/// Generates an object supporting the `IteratorResult` interface.
#[inline]
pub fn create_iter_result_object(value: JsValue, done: bool, context: &mut Context) -> JsValue {
let _timer = Profiler::global().start_event("create_iter_result_object", "init");

// 1. Assert: Type(done) is Boolean.
// 2. Let obj be ! OrdinaryObjectCreate(%Object.prototype%).
let obj = context.construct_object();
Expand Down Expand Up @@ -106,6 +111,7 @@ impl JsValue {
/// - [ECMA reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-getiterator
#[inline]
pub fn get_iterator(
&self,
context: &mut Context,
Expand Down Expand Up @@ -168,6 +174,7 @@ impl JsValue {
/// - [ECMA reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-%iteratorprototype%-object
#[inline]
fn create_iterator_prototype(context: &mut Context) -> JsObject {
let _timer = Profiler::global().start_event("Iterator Prototype", "init");

Expand All @@ -182,24 +189,71 @@ fn create_iterator_prototype(context: &mut Context) -> JsObject {
iterator_prototype
}

#[derive(Debug)]
pub struct IteratorResult {
object: JsObject,
}

impl IteratorResult {
/// Get `done` property of iterator result object.
///
/// More information:
/// - [ECMA reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-iteratorclose
#[inline]
pub fn complete(&self, context: &mut Context) -> JsResult<bool> {
// 1. Return ToBoolean(? Get(iterResult, "done")).
Ok(self.object.get("done", context)?.to_boolean())
}

/// Get `value` property of iterator result object.
///
/// More information:
/// - [ECMA reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-iteratorvalue
#[inline]
pub fn value(&self, context: &mut Context) -> JsResult<JsValue> {
// 1. Return ? Get(iterResult, "value").
self.object.get("value", context)
}
}
/// An Iterator Record is a Record value used to encapsulate an
/// `Iterator` or `AsyncIterator` along with the next method.
///
/// More information:
/// - [ECMA reference][spec]
///
/// [spec]:https://tc39.es/ecma262/#table-iterator-record-fields
#[derive(Debug)]
pub struct IteratorRecord {
/// `[[Iterator]]`
///
/// An object that conforms to the Iterator or AsyncIterator interface.
iterator_object: JsValue,

/// `[[NextMethod]]`
///
/// The next method of the `[[Iterator]]` object.
next_function: JsValue,
}

impl IteratorRecord {
#[inline]
pub fn new(iterator_object: JsValue, next_function: JsValue) -> Self {
Self {
iterator_object,
next_function,
}
}

#[inline]
pub(crate) fn iterator_object(&self) -> &JsValue {
&self.iterator_object
}

#[inline]
pub(crate) fn next_function(&self) -> &JsValue {
&self.next_function
}
Expand All @@ -210,12 +264,50 @@ impl IteratorRecord {
/// - [ECMA reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-iteratornext
pub(crate) fn next(&self, context: &mut Context) -> JsResult<IteratorResult> {
let next = context.call(&self.next_function, &self.iterator_object, &[])?;
let done = next.get_field("done", context)?.to_boolean();
#[inline]
pub(crate) fn next(
&self,
value: Option<JsValue>,
context: &mut Context,
) -> JsResult<IteratorResult> {
let _timer = Profiler::global().start_event("IteratorRecord::next", "iterator");

// 1. If value is not present, then
// a. Let result be ? Call(iteratorRecord.[[NextMethod]], iteratorRecord.[[Iterator]]).
// 2. Else,
// a. Let result be ? Call(iteratorRecord.[[NextMethod]], iteratorRecord.[[Iterator]], « value »).
let result = if let Some(value) = value {
context.call(&self.next_function, &self.iterator_object, &[value])?
} else {
context.call(&self.next_function, &self.iterator_object, &[])?
};

// 3. If Type(result) is not Object, throw a TypeError exception.
// 4. Return result.
if let Some(o) = result.as_object() {
Ok(IteratorResult { object: o.clone() })
} else {
context.throw_type_error("next value should be an object")
}
}

#[inline]
pub(crate) fn step(&self, context: &mut Context) -> JsResult<Option<IteratorResult>> {
let _timer = Profiler::global().start_event("IteratorRecord::step", "iterator");

// 1. Let result be ? IteratorNext(iteratorRecord).
let result = self.next(None, context)?;

let value = next.get_field("value", context)?;
Ok(IteratorResult { value, done })
// 2. Let done be ? IteratorComplete(result).
let done = result.complete(context)?;

// 3. If done is true, return false.
if done {
return Ok(None);
}

// 4. Return result.
Ok(Some(result))
}

/// Cleanup the iterator
Expand All @@ -224,16 +316,18 @@ impl IteratorRecord {
/// - [ECMA reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-iteratorclose
#[inline]
pub(crate) fn close(
&self,
completion: JsResult<JsValue>,
context: &mut Context,
) -> JsResult<JsValue> {
let _timer = Profiler::global().start_event("IteratorRecord::close", "iterator");

// 1. Assert: Type(iteratorRecord.[[Iterator]]) is Object.
// 2. Let iterator be iteratorRecord.[[Iterator]].
// 3. Let innerResult be GetMethod(iterator, "return").
let inner_result = self.iterator_object.get_method("return", context);
//let mut inner_result = self.iterator_object.get_field("return", context);

// 4. If innerResult.[[Type]] is normal, then
if let Ok(inner_value) = inner_result {
Expand Down Expand Up @@ -281,6 +375,8 @@ pub(crate) fn iterable_to_list(
items: &JsValue,
method: Option<JsValue>,
) -> JsResult<Vec<JsValue>> {
let _timer = Profiler::global().start_event("iterable_to_list", "iterator");

// 1. If method is present, then
let iterator_record = if let Some(method) = method {
// a. Let iteratorRecord be ? GetIterator(items, sync, method).
Expand All @@ -300,21 +396,11 @@ pub(crate) fn iterable_to_list(
// b. If next is not false, then
// i. Let nextValue be ? IteratorValue(next).
// ii. Append nextValue to the end of the List values.
loop {
let next = iterator_record.next(context)?;
if next.done {
break;
}

values.push(next.value);
while let Some(next) = iterator_record.step(context)? {
let next_value = next.value(context)?;
values.push(next_value);
}

// 6. Return values.
Ok(values)
}

#[derive(Debug)]
pub struct IteratorResult {
pub value: JsValue,
pub done: bool,
}
17 changes: 9 additions & 8 deletions boa_engine/src/builtins/map/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@
use self::{map_iterator::MapIterator, ordered_map::OrderedMap};
use super::JsArgs;
use crate::{
builtins::{iterable::IteratorResult, BuiltIn},
builtins::BuiltIn,
context::StandardObjects,
object::{
internal_methods::get_prototype_from_constructor, ConstructorBuilder, FunctionBuilder,
Expand Down Expand Up @@ -547,19 +547,20 @@ pub(crate) fn add_entries_from_iterable(
// 3. Repeat,
loop {
// a. Let next be ? IteratorStep(iteratorRecord).
// c. Let nextItem be ? IteratorValue(next).
let IteratorResult { value, done } = iterator_record.next(context)?;
let next = iterator_record.step(context)?;

// b. If next is false, return target.
if done {
// c. Let nextItem be ? IteratorValue(next).
let next_item = if let Some(next) = next {
next.value(context)?
} else {
return Ok(target.clone().into());
}
};

let next_item = if let Some(obj) = value.as_object() {
let next_item = if let Some(obj) = next_item.as_object() {
obj
}
// d. If Type(nextItem) is not Object, then
else {
} else {
// i. Let error be ThrowCompletion(a newly created TypeError object).
let err = context
.throw_type_error("cannot get key and value from primitive item of `iterable`");
Expand Down
40 changes: 20 additions & 20 deletions boa_engine/src/builtins/set/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -118,53 +118,53 @@ impl Set {
args: &[JsValue],
context: &mut Context,
) -> JsResult<JsValue> {
// 1
// 1. If NewTarget is undefined, throw a TypeError exception.
if new_target.is_undefined() {
return context
.throw_type_error("calling a builtin Set constructor without new is forbidden");
}

// 2
// 2. Let set be ? OrdinaryCreateFromConstructor(NewTarget, "%Set.prototype%", « [[SetData]] »).
// 3. Set set.[[SetData]] to a new empty List.
let prototype =
get_prototype_from_constructor(new_target, StandardObjects::set_object, context)?;
let set = JsObject::from_proto_and_data(prototype, ObjectData::set(OrderedSet::default()));

let obj = JsObject::from_proto_and_data(prototype, ObjectData::set(OrderedSet::default()));

// 4. If iterable is either undefined or null, return set.
let iterable = args.get_or_undefined(0);
// 4
if iterable.is_null_or_undefined() {
return Ok(obj.into());
return Ok(set.into());
}

// 5
let adder = obj.get("add", context)?;
// 5. Let adder be ? Get(set, "add").
let adder = set.get("add", context)?;

// 6
// 6. If IsCallable(adder) is false, throw a TypeError exception.
let adder = adder.as_callable().ok_or_else(|| {
context.construct_type_error("'add' of 'newTarget' is not a function")
})?;

// 7
// 7. Let iteratorRecord be ? GetIterator(iterable).
let iterator_record = iterable.clone().get_iterator(context, None, None)?;

// 8.a
let mut next = iterator_record.next(context)?;

// 8
while !next.done {
// 8. Repeat,
// a. Let next be ? IteratorStep(iteratorRecord).
// b. If next is false, return set.
// c. Let nextValue be ? IteratorValue(next).
// d. Let status be Completion(Call(adder, set, « nextValue »)).
// e. IfAbruptCloseIterator(status, iteratorRecord).
while let Some(next) = iterator_record.step(context)? {
// c
let next_value = next.value;
let next_value = next.value(context)?;

// d, e
if let Err(status) = adder.call(&obj.clone().into(), &[next_value], context) {
if let Err(status) = adder.call(&set.clone().into(), &[next_value], context) {
return iterator_record.close(Err(status), context);
}

next = iterator_record.next(context)?;
}

// 8.b
Ok(obj.into())
Ok(set.into())
}

/// `get Set [ @@species ]`
Expand Down
17 changes: 0 additions & 17 deletions boa_engine/src/value/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -316,23 +316,6 @@ impl JsValue {
}
}

/**
Resolve the property in the object and get its value, or undefined if this is not an object or the field doesn't exist
`get_field` receives a Property from get_prop(). It should then return the `[[Get]]` result value if that's set, otherwise fall back to `[[Value]]`
*/
pub(crate) fn get_field<K>(&self, key: K, context: &mut Context) -> JsResult<Self>
where
K: Into<PropertyKey>,
{
let _timer = Profiler::global().start_event("Value::get_field", "value");
if let Self::Object(ref obj) = *self {
obj.clone()
.__get__(&key.into(), obj.clone().into(), context)
} else {
Ok(Self::undefined())
}
}

/// Set the kind of an object.
#[inline]
pub fn set_data(&self, data: ObjectData) {
Expand Down
Loading

0 comments on commit a9a82a7

Please sign in to comment.