Libraries: Move to Userland/Libraries/

Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2020, Matthew Olsson <matthewcolsson@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibJS/Runtime/Error.h>
+#include <LibJS/Runtime/GlobalObject.h>
+#include <LibJS/Runtime/IteratorOperations.h>
+
+namespace JS {
+
+Object* get_iterator(GlobalObject& global_object, Value value, String hint, Value method)
+{
+    auto& vm = global_object.vm();
+    ASSERT(hint == "sync" || hint == "async");
+    if (method.is_empty()) {
+        if (hint == "async")
+            TODO();
+        auto object = value.to_object(global_object);
+        if (!object)
+            return {};
+        method = object->get(global_object.vm().well_known_symbol_iterator());
+        if (vm.exception())
+            return {};
+    }
+    if (!method.is_function()) {
+        vm.throw_exception<TypeError>(global_object, ErrorType::NotIterable, value.to_string_without_side_effects());
+        return nullptr;
+    }
+    auto iterator = vm.call(method.as_function(), value);
+    if (vm.exception())
+        return {};
+    if (!iterator.is_object()) {
+        vm.throw_exception<TypeError>(global_object, ErrorType::NotIterable, value.to_string_without_side_effects());
+        return nullptr;
+    }
+    return &iterator.as_object();
+}
+
+Object* iterator_next(Object& iterator, Value value)
+{
+    auto& vm = iterator.vm();
+    auto& global_object = iterator.global_object();
+    auto next_method = iterator.get(vm.names.next);
+    if (vm.exception())
+        return {};
+
+    if (!next_method.is_function()) {
+        vm.throw_exception<TypeError>(global_object, ErrorType::IterableNextNotAFunction);
+        return nullptr;
+    }
+
+    Value result;
+    if (value.is_empty())
+        result = vm.call(next_method.as_function(), &iterator);
+    else
+        result = vm.call(next_method.as_function(), &iterator, value);
+
+    if (vm.exception())
+        return {};
+    if (!result.is_object()) {
+        vm.throw_exception<TypeError>(global_object, ErrorType::IterableNextBadReturn);
+        return nullptr;
+    }
+
+    return &result.as_object();
+}
+
+void iterator_close([[maybe_unused]] Object& iterator)
+{
+    TODO();
+}
+
+Value create_iterator_result_object(GlobalObject& global_object, Value value, bool done)
+{
+    auto& vm = global_object.vm();
+    auto* object = Object::create_empty(global_object);
+    object->define_property(vm.names.value, value);
+    object->define_property(vm.names.done, Value(done));
+    return object;
+}
+
+void get_iterator_values(GlobalObject& global_object, Value value, AK::Function<IterationDecision(Value)> callback)
+{
+    auto& vm = global_object.vm();
+
+    auto iterator = get_iterator(global_object, value);
+    if (!iterator)
+        return;
+
+    while (true) {
+        auto next_object = iterator_next(*iterator);
+        if (!next_object)
+            return;
+
+        auto done_property = next_object->get(vm.names.done);
+        if (vm.exception())
+            return;
+
+        if (!done_property.is_empty() && done_property.to_boolean())
+            return;
+
+        auto next_value = next_object->get(vm.names.value);
+        if (vm.exception())
+            return;
+
+        auto result = callback(next_value);
+        if (result == IterationDecision::Break)
+            return;
+        ASSERT(result == IterationDecision::Continue);
+    }
+}
+
+}