1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/*
* Copyright (c) 2020, Matthew Olsson <mattco@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/AsyncFromSyncIteratorPrototype.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/FunctionObject.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/IteratorOperations.h>
#include <LibJS/Runtime/TemporaryClearException.h>
namespace JS {
// 7.4.1 GetIterator ( obj [ , hint [ , method ] ] ), https://tc39.es/ecma262/#sec-getiterator
ThrowCompletionOr<Object*> get_iterator(GlobalObject& global_object, Value value, IteratorHint hint, Value method)
{
auto& vm = global_object.vm();
if (method.is_empty()) {
if (hint == IteratorHint::Async) {
auto* async_method = TRY(value.get_method(global_object, *vm.well_known_symbol_async_iterator()));
if (async_method == nullptr) {
auto* sync_method = TRY(value.get_method(global_object, *vm.well_known_symbol_iterator()));
auto* sync_iterator_record = TRY(get_iterator(global_object, value, IteratorHint::Sync, sync_method));
return TRY(create_async_from_sync_iterator(global_object, *sync_iterator_record));
}
method = Value(async_method);
} else {
method = TRY(value.get_method(global_object, *vm.well_known_symbol_iterator()));
}
}
if (!method.is_function())
return vm.throw_completion<TypeError>(global_object, ErrorType::NotIterable, value.to_string_without_side_effects());
auto iterator = TRY(vm.call(method.as_function(), value));
if (!iterator.is_object())
return vm.throw_completion<TypeError>(global_object, ErrorType::NotIterable, value.to_string_without_side_effects());
return &iterator.as_object();
}
// 7.4.2 IteratorNext ( iteratorRecord [ , value ] ), https://tc39.es/ecma262/#sec-iteratornext
ThrowCompletionOr<Object*> iterator_next(Object& iterator, Value value)
{
// FIXME: Implement using iterator records, not ordinary objects
auto& vm = iterator.vm();
auto& global_object = iterator.global_object();
auto next_method = TRY(iterator.get(vm.names.next));
if (!next_method.is_function())
return vm.throw_completion<TypeError>(global_object, ErrorType::IterableNextNotAFunction);
Value result;
if (value.is_empty())
result = TRY(vm.call(next_method.as_function(), &iterator));
else
result = TRY(vm.call(next_method.as_function(), &iterator, value));
if (!result.is_object())
return vm.throw_completion<TypeError>(global_object, ErrorType::IterableNextBadReturn);
return &result.as_object();
}
// 7.4.3 IteratorComplete ( iterResult ), https://tc39.es/ecma262/#sec-iteratorcomplete
ThrowCompletionOr<bool> iterator_complete(GlobalObject& global_object, Object& iterator_result)
{
auto& vm = global_object.vm();
// 1. Return ! ToBoolean(? Get(iterResult, "done")).
return TRY(iterator_result.get(vm.names.done)).to_boolean();
}
// 7.4.4 IteratorValue ( iterResult ), https://tc39.es/ecma262/#sec-iteratorvalue
ThrowCompletionOr<Value> iterator_value(GlobalObject& global_object, Object& iterator_result)
{
auto& vm = global_object.vm();
// 1. Return ? Get(iterResult, "value").
return TRY(iterator_result.get(vm.names.value));
}
// 7.4.5 IteratorStep ( iteratorRecord ), https://tc39.es/ecma262/#sec-iteratorstep
ThrowCompletionOr<Object*> iterator_step(GlobalObject& global_object, Object& iterator)
{
auto* result = TRY(iterator_next(iterator));
auto done = TRY(iterator_complete(global_object, *result));
if (done)
return nullptr;
return result;
}
// 7.4.6 IteratorClose ( iteratorRecord, completion ), https://tc39.es/ecma262/#sec-iteratorclose
// 7.4.8 AsyncIteratorClose ( iteratorRecord, completion ), https://tc39.es/ecma262/#sec-asynciteratorclose
// NOTE: These only differ in that async awaits the inner value after the call.
static Completion iterator_close_(Object& iterator, Completion completion, IteratorHint iterator_hint)
{
auto& vm = iterator.vm();
auto& global_object = iterator.global_object();
// The callers of iterator_close() are often in an exceptional state.
// Temporarily clear that exception for invocation(s) to Call.
TemporaryClearException clear_exception(vm);
// 3. Let innerResult be GetMethod(iterator, "return").
auto inner_result_or_error = Value(&iterator).get_method(global_object, vm.names.return_);
Value inner_result;
// 4. If innerResult.[[Type]] is normal, then
if (!inner_result_or_error.is_error()) {
// a. Let return be innerResult.[[Value]].
auto* return_method = inner_result_or_error.release_value();
// b. If return is undefined, return Completion(completion).
if (!return_method)
return completion;
vm.stop_unwind();
// c. Set innerResult to Call(return, iterator).
auto result_or_error = vm.call(*return_method, &iterator);
if (result_or_error.is_error()) {
inner_result_or_error = result_or_error.release_error();
} else {
inner_result = result_or_error.release_value();
// Note: If this is AsyncIteratorClose perform one extra step.
if (iterator_hint == IteratorHint::Async) {
// d. If innerResult.[[Type]] is normal, set innerResult to Await(innerResult.[[Value]]).
inner_result = TRY(await(global_object, inner_result));
}
}
}
// 5. If completion.[[Type]] is throw, return Completion(completion).
if (completion.is_error())
return completion;
// 6. If innerResult.[[Type]] is throw, return Completion(innerResult).
if (inner_result_or_error.is_error())
return inner_result_or_error.release_error();
// 7. If Type(innerResult.[[Value]]) is not Object, throw a TypeError exception.
if (!inner_result.is_object())
return vm.throw_completion<TypeError>(global_object, ErrorType::IterableReturnBadReturn);
// 8. Return Completion(completion).
return completion;
}
// 7.4.6 IteratorClose ( iteratorRecord, completion ), https://tc39.es/ecma262/#sec-iteratorclose
Completion iterator_close(Object& iterator, Completion completion)
{
return iterator_close_(iterator, move(completion), IteratorHint::Sync);
}
// 7.4.8 AsyncIteratorClose ( iteratorRecord, completion ), https://tc39.es/ecma262/#sec-asynciteratorclose
Completion async_iterator_close(Object& iterator, Completion completion)
{
return iterator_close_(iterator, move(completion), IteratorHint::Async);
}
// 7.4.9 CreateIterResultObject ( value, done ), https://tc39.es/ecma262/#sec-createiterresultobject
Object* create_iterator_result_object(GlobalObject& global_object, Value value, bool done)
{
auto& vm = global_object.vm();
auto* object = Object::create(global_object, global_object.object_prototype());
MUST(object->create_data_property_or_throw(vm.names.value, value));
MUST(object->create_data_property_or_throw(vm.names.done, Value(done)));
return object;
}
// 7.4.11 IterableToList ( items [ , method ] ), https://tc39.es/ecma262/#sec-iterabletolist
ThrowCompletionOr<MarkedValueList> iterable_to_list(GlobalObject& global_object, Value iterable, Value method)
{
auto& vm = global_object.vm();
MarkedValueList values(vm.heap());
TRY(get_iterator_values(
global_object, iterable, [&](auto value) -> Optional<Completion> {
values.append(value);
return {};
},
method));
return { move(values) };
}
Completion get_iterator_values(GlobalObject& global_object, Value iterable, IteratorValueCallback callback, Value method)
{
auto* iterator = TRY(get_iterator(global_object, iterable, IteratorHint::Sync, method));
while (true) {
auto* next_object = TRY(iterator_step(global_object, *iterator));
if (!next_object)
return {};
auto next_value = TRY(iterator_value(global_object, *next_object));
if (auto completion = callback(next_value); completion.has_value())
return iterator_close(*iterator, completion.release_value());
}
}
}
|
