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/*
* Copyright (c) 2020-2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/StringView.h>
#include <LibJS/Runtime/Completion.h>
#include <LibJS/Runtime/Object.h>
namespace JS {
struct Variable {
Value value;
DeclarationKind declaration_kind;
};
#define JS_ENVIRONMENT(class_, base_class) JS_CELL(class_, base_class)
class Environment : public Cell {
JS_CELL(Environment, Cell);
public:
virtual bool has_this_binding() const { return false; }
virtual ThrowCompletionOr<Value> get_this_binding(VM&) const { return Value {}; }
virtual Object* with_base_object() const { return nullptr; }
virtual ThrowCompletionOr<bool> has_binding([[maybe_unused]] FlyString const& name, [[maybe_unused]] Optional<size_t>* out_index = nullptr) const { return false; }
virtual ThrowCompletionOr<void> create_mutable_binding(VM&, [[maybe_unused]] FlyString const& name, [[maybe_unused]] bool can_be_deleted) { return {}; }
virtual ThrowCompletionOr<void> create_immutable_binding(VM&, [[maybe_unused]] FlyString const& name, [[maybe_unused]] bool strict) { return {}; }
virtual ThrowCompletionOr<void> initialize_binding(VM&, [[maybe_unused]] FlyString const& name, Value) { return {}; }
virtual ThrowCompletionOr<void> set_mutable_binding(VM&, [[maybe_unused]] FlyString const& name, Value, [[maybe_unused]] bool strict) { return {}; }
virtual ThrowCompletionOr<Value> get_binding_value(VM&, [[maybe_unused]] FlyString const& name, [[maybe_unused]] bool strict) { return Value {}; }
virtual ThrowCompletionOr<bool> delete_binding(VM&, [[maybe_unused]] FlyString const& name) { return false; }
// [[OuterEnv]]
Environment* outer_environment() { return m_outer_environment; }
Environment const* outer_environment() const { return m_outer_environment; }
virtual bool is_global_environment() const { return false; }
virtual bool is_declarative_environment() const { return false; }
virtual bool is_function_environment() const { return false; }
template<typename T>
bool fast_is() const = delete;
// This flag is set on the entire variable environment chain when direct eval() is performed.
// It is used to disable non-local variable access caching.
bool is_permanently_screwed_by_eval() const { return m_permanently_screwed_by_eval; }
void set_permanently_screwed_by_eval();
protected:
explicit Environment(Environment* parent);
virtual void visit_edges(Visitor&) override;
private:
virtual bool is_environment() const final { return true; }
bool m_permanently_screwed_by_eval { false };
Environment* m_outer_environment { nullptr };
};
}
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