LibJS: Use FlyString for identifiers

This makes variable and property lookups a lot faster since comparing
two FlyStrings is O(1).

19 files changed, 67 insertions, 57 deletions

diff --git a/Libraries/LibJS/AST.cpp b/Libraries/LibJS/AST.cpp
index 591301b257..d3b34dc027 100644
--- a/Libraries/LibJS/AST.cpp
+++ b/Libraries/LibJS/AST.cpp
@@ -657,7 +657,7 @@ void MemberExpression::dump(int indent) const
     m_property->dump(indent + 1);
 }
 
-String MemberExpression::computed_property_name(Interpreter& interpreter) const
+FlyString MemberExpression::computed_property_name(Interpreter& interpreter) const
 {
     if (!is_computed()) {
         ASSERT(m_property->is_identifier());
diff --git a/Libraries/LibJS/AST.h b/Libraries/LibJS/AST.h
index 2ff6a06722..3d58f0b395 100644
--- a/Libraries/LibJS/AST.h
+++ b/Libraries/LibJS/AST.h
@@ -30,6 +30,7 @@
 #include <AK/NonnullRefPtrVector.h>
 #include <AK/RefPtr.h>
 #include <AK/String.h>
+#include <AK/FlyString.h>
 #include <AK/Vector.h>
 #include <LibJS/Forward.h>
 #include <LibJS/Runtime/Value.h>
@@ -130,13 +131,13 @@ class Expression : public ASTNode {
 
 class FunctionNode {
 public:
-    String name() const { return m_name; }
+    const FlyString& name() const { return m_name; }
     const ScopeNode& body() const { return *m_body; }
-    const Vector<String>& parameters() const { return m_parameters; };
+    const Vector<FlyString>& parameters() const { return m_parameters; };
 
 protected:
-    FunctionNode(String name, NonnullRefPtr<ScopeNode> body, Vector<String> parameters = {})
-        : m_name(move(name))
+    FunctionNode(const FlyString& name, NonnullRefPtr<ScopeNode> body, Vector<FlyString> parameters = {})
+        : m_name(name)
         , m_body(move(body))
         , m_parameters(move(parameters))
     {
@@ -145,9 +146,9 @@ protected:
     void dump(int indent, const char* class_name) const;
 
 private:
-    String m_name;
+    FlyString m_name;
     NonnullRefPtr<ScopeNode> m_body;
-    const Vector<String> m_parameters;
+    const Vector<FlyString> m_parameters;
 };
 
 class FunctionDeclaration final
@@ -156,7 +157,7 @@ class FunctionDeclaration final
 public:
     static bool must_have_name() { return true; }
 
-    FunctionDeclaration(String name, NonnullRefPtr<ScopeNode> body, Vector<String> parameters = {})
+    FunctionDeclaration(String name, NonnullRefPtr<ScopeNode> body, Vector<FlyString> parameters = {})
         : FunctionNode(move(name), move(body), move(parameters))
     {
     }
@@ -173,8 +174,8 @@ class FunctionExpression final : public Expression
 public:
     static bool must_have_name() { return false; }
 
-    FunctionExpression(String name, NonnullRefPtr<ScopeNode> body, Vector<String> parameters = {})
-        : FunctionNode(move(name), move(body), move(parameters))
+    FunctionExpression(const FlyString& name, NonnullRefPtr<ScopeNode> body, Vector<FlyString> parameters = {})
+        : FunctionNode(name, move(body), move(parameters))
     {
     }
 
@@ -425,17 +426,13 @@ private:
 
 class NullLiteral final : public Literal {
 public:
-    explicit NullLiteral()
-    {
-    }
+    explicit NullLiteral() {}
 
     virtual Value execute(Interpreter&) const override;
     virtual void dump(int indent) const override;
 
 private:
     virtual const char* class_name() const override { return "NullLiteral"; }
-
-    String m_value;
 };
 
 class UndefinedLiteral final : public Literal {
@@ -453,12 +450,12 @@ private:
 
 class Identifier final : public Expression {
 public:
-    explicit Identifier(String string)
-        : m_string(move(string))
+    explicit Identifier(const FlyString& string)
+        : m_string(string)
     {
     }
 
-    const String& string() const { return m_string; }
+    const FlyString& string() const { return m_string; }
 
     virtual Value execute(Interpreter&) const override;
     virtual void dump(int indent) const override;
@@ -467,7 +464,7 @@ public:
 private:
     virtual const char* class_name() const override { return "Identifier"; }
 
-    String m_string;
+    FlyString m_string;
 };
 
 class CallExpression : public Expression {
@@ -573,7 +570,7 @@ private:
 
 class ObjectExpression : public Expression {
 public:
-    ObjectExpression(HashMap<String, NonnullRefPtr<Expression>> properties = {})
+    ObjectExpression(HashMap<FlyString, NonnullRefPtr<Expression>> properties = {})
         : m_properties(move(properties))
     {
     }
@@ -584,7 +581,7 @@ public:
 private:
     virtual const char* class_name() const override { return "ObjectExpression"; }
 
-    HashMap<String, NonnullRefPtr<Expression>> m_properties;
+    HashMap<FlyString, NonnullRefPtr<Expression>> m_properties;
 };
 
 class ArrayExpression : public Expression {
@@ -621,7 +618,7 @@ public:
     const Expression& object() const { return *m_object; }
     const Expression& property() const { return *m_property; }
 
-    String computed_property_name(Interpreter&) const;
+    FlyString computed_property_name(Interpreter&) const;
 
 private:
     virtual bool is_member_expression() const override { return true; }
diff --git a/Libraries/LibJS/Interpreter.cpp b/Libraries/LibJS/Interpreter.cpp
index 4485b5c86a..47a63646d1 100644
--- a/Libraries/LibJS/Interpreter.cpp
+++ b/Libraries/LibJS/Interpreter.cpp
@@ -65,7 +65,7 @@ Value Interpreter::run(const ScopeNode& scope_node, Vector<Argument> arguments,
 
 void Interpreter::enter_scope(const ScopeNode& scope_node, Vector<Argument> arguments, ScopeType scope_type)
 {
-    HashMap<String, Variable> scope_variables_with_declaration_type;
+    HashMap<FlyString, Variable> scope_variables_with_declaration_type;
     for (auto& argument : arguments) {
         scope_variables_with_declaration_type.set(argument.name, { argument.value, DeclarationType::Var });
     }
@@ -83,7 +83,7 @@ void Interpreter::do_return()
     dbg() << "FIXME: Implement Interpreter::do_return()";
 }
 
-void Interpreter::declare_variable(String name, DeclarationType declaration_type)
+void Interpreter::declare_variable(const FlyString& name, DeclarationType declaration_type)
 {
     switch (declaration_type) {
     case DeclarationType::Var:
@@ -110,7 +110,7 @@ void Interpreter::declare_variable(String name, DeclarationType declaration_type
     }
 }
 
-void Interpreter::set_variable(String name, Value value, bool first_assignment)
+void Interpreter::set_variable(const FlyString& name, Value value, bool first_assignment)
 {
     for (ssize_t i = m_scope_stack.size() - 1; i >= 0; --i) {
         auto& scope = m_scope_stack.at(i);
@@ -128,7 +128,7 @@ void Interpreter::set_variable(String name, Value value, bool first_assignment)
     global_object().put(move(name), move(value));
 }
 
-Value Interpreter::get_variable(const String& name)
+Value Interpreter::get_variable(const FlyString& name)
 {
     for (ssize_t i = m_scope_stack.size() - 1; i >= 0; --i) {
         auto& scope = m_scope_stack.at(i);
diff --git a/Libraries/LibJS/Interpreter.h b/Libraries/LibJS/Interpreter.h
index 52962c6d78..4c749fcd0e 100644
--- a/Libraries/LibJS/Interpreter.h
+++ b/Libraries/LibJS/Interpreter.h
@@ -28,6 +28,7 @@
 
 #include <AK/HashMap.h>
 #include <AK/String.h>
+#include <AK/FlyString.h>
 #include <AK/Vector.h>
 #include <LibJS/Forward.h>
 #include <LibJS/Heap/Heap.h>
@@ -48,7 +49,7 @@ struct Variable {
 struct ScopeFrame {
     ScopeType type;
     NonnullRefPtr<ScopeNode> scope_node;
-    HashMap<String, Variable> variables;
+    HashMap<FlyString, Variable> variables;
 };
 
 struct CallFrame {
@@ -57,7 +58,7 @@ struct CallFrame {
 };
 
 struct Argument {
-    String name;
+    FlyString name;
     Value value;
 };
 
@@ -75,9 +76,9 @@ public:
 
     void do_return();
 
-    Value get_variable(const String& name);
-    void set_variable(String name, Value, bool first_assignment = false);
-    void declare_variable(String name, DeclarationType);
+    Value get_variable(const FlyString& name);
+    void set_variable(const FlyString& name, Value, bool first_assignment = false);
+    void declare_variable(const FlyString& name, DeclarationType);
 
     void gather_roots(Badge<Heap>, HashTable<Cell*>&);
 
@@ -86,7 +87,11 @@ public:
 
     Value call(Function*, Value this_value, const Vector<Value>& arguments);
 
-    CallFrame& push_call_frame() { m_call_stack.append({ js_undefined(), {} }); return m_call_stack.last(); }
+    CallFrame& push_call_frame()
+    {
+        m_call_stack.append({ js_undefined(), {} });
+        return m_call_stack.last();
+    }
     void pop_call_frame() { m_call_stack.take_last(); }
     Value this_value() const
     {
diff --git a/Libraries/LibJS/Parser.cpp b/Libraries/LibJS/Parser.cpp
index 7ef64a3d2b..6b5a09cb18 100644
--- a/Libraries/LibJS/Parser.cpp
+++ b/Libraries/LibJS/Parser.cpp
@@ -271,7 +271,7 @@ NonnullRefPtr<Expression> Parser::parse_unary_prefixed_expression()
 
 NonnullRefPtr<ObjectExpression> Parser::parse_object_expression()
 {
-    HashMap<String, NonnullRefPtr<Expression>> properties;
+    HashMap<FlyString, NonnullRefPtr<Expression>> properties;
     consume(TokenType::CurlyOpen);
 
     while (!match(TokenType::CurlyClose)) {
@@ -471,7 +471,7 @@ NonnullRefPtr<FunctionNodeType> Parser::parse_function_node()
             name = consume(TokenType::Identifier).value();
     }
     consume(TokenType::ParenOpen);
-    Vector<String> parameters;
+    Vector<FlyString> parameters;
     while (match(TokenType::Identifier)) {
         auto parameter = consume(TokenType::Identifier).value();
         parameters.append(parameter);
diff --git a/Libraries/LibJS/Runtime/Array.cpp b/Libraries/LibJS/Runtime/Array.cpp
index e8cfb28f1b..cab66eb3a5 100644
--- a/Libraries/LibJS/Runtime/Array.cpp
+++ b/Libraries/LibJS/Runtime/Array.cpp
@@ -59,7 +59,7 @@ void Array::visit_children(Cell::Visitor& visitor)
         visitor.visit(element);
 }
 
-Optional<Value> Array::get_own_property(const String& property_name) const
+Optional<Value> Array::get_own_property(const FlyString& property_name) const
 {
     bool ok;
     i32 index = property_name.to_int(ok);
@@ -70,7 +70,7 @@ Optional<Value> Array::get_own_property(const String& property_name) const
     return Object::get_own_property(property_name);
 }
 
-bool Array::put_own_property(const String& property_name, Value value)
+bool Array::put_own_property(const FlyString& property_name, Value value)
 {
     bool ok;
     i32 index = property_name.to_int(ok);
diff --git a/Libraries/LibJS/Runtime/Array.h b/Libraries/LibJS/Runtime/Array.h
index 828b70c33f..930b7a586c 100644
--- a/Libraries/LibJS/Runtime/Array.h
+++ b/Libraries/LibJS/Runtime/Array.h
@@ -45,8 +45,8 @@ private:
     virtual const char* class_name() const override { return "Array"; }
     virtual void visit_children(Cell::Visitor&) override;
     virtual bool is_array() const override { return true; }
-    virtual Optional<Value> get_own_property(const String& property_name) const override;
-    virtual bool put_own_property(const String& property_name, Value) override;
+    virtual Optional<Value> get_own_property(const FlyString& property_name) const override;
+    virtual bool put_own_property(const FlyString& property_name, Value) override;
 
     Vector<Value> m_elements;
 };
diff --git a/Libraries/LibJS/Runtime/ConsoleObject.cpp b/Libraries/LibJS/Runtime/ConsoleObject.cpp
index b9c3a34ca7..c5e307a982 100644
--- a/Libraries/LibJS/Runtime/ConsoleObject.cpp
+++ b/Libraries/LibJS/Runtime/ConsoleObject.cpp
@@ -25,6 +25,7 @@
  */
 
 #include <AK/Function.h>
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/ConsoleObject.h>
 #include <stdio.h>
 
diff --git a/Libraries/LibJS/Runtime/MathObject.cpp b/Libraries/LibJS/Runtime/MathObject.cpp
index 23ef4d6bda..4c2e3764fb 100644
--- a/Libraries/LibJS/Runtime/MathObject.cpp
+++ b/Libraries/LibJS/Runtime/MathObject.cpp
@@ -25,6 +25,7 @@
  */
 
 #include <AK/Function.h>
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/MathObject.h>
 
 namespace JS {
diff --git a/Libraries/LibJS/Runtime/Object.cpp b/Libraries/LibJS/Runtime/Object.cpp
index 2cf1f7cc0a..d72851ad50 100644
--- a/Libraries/LibJS/Runtime/Object.cpp
+++ b/Libraries/LibJS/Runtime/Object.cpp
@@ -44,7 +44,7 @@ Object::~Object()
 {
 }
 
-Optional<Value> Object::get_own_property(const String& property_name) const
+Optional<Value> Object::get_own_property(const FlyString& property_name) const
 {
     auto value_here = m_properties.get(property_name);
     if (value_here.has_value() && value_here.value().is_object() && value_here.value().as_object()->is_native_property())
@@ -52,7 +52,7 @@ Optional<Value> Object::get_own_property(const String& property_name) const
     return value_here;
 }
 
-bool Object::put_own_property(const String& property_name, Value value)
+bool Object::put_own_property(const FlyString& property_name, Value value)
 {
     auto value_here = m_properties.get(property_name);
     if (value_here.has_value() && value_here.value().is_object() && value_here.value().as_object()->is_native_property()) {
@@ -63,7 +63,7 @@ bool Object::put_own_property(const String& property_name, Value value)
     return true;
 }
 
-Value Object::get(const String& property_name) const
+Value Object::get(const FlyString& property_name) const
 {
     const Object* object = this;
     while (object) {
@@ -75,7 +75,7 @@ Value Object::get(const String& property_name) const
     return js_undefined();
 }
 
-void Object::put(const String& property_name, Value value)
+void Object::put(const FlyString& property_name, Value value)
 {
     Object* object = this;
     while (object) {
@@ -93,12 +93,12 @@ void Object::put(const String& property_name, Value value)
     put_own_property(property_name, value);
 }
 
-void Object::put_native_function(String property_name, AK::Function<Value(Object*, Vector<Value>)> native_function)
+void Object::put_native_function(const FlyString& property_name, AK::Function<Value(Object*, Vector<Value>)> native_function)
 {
     put(property_name, heap().allocate<NativeFunction>(move(native_function)));
 }
 
-void Object::put_native_property(String property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter)
+void Object::put_native_property(const FlyString& property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter)
 {
     put(property_name, heap().allocate<NativeProperty>(move(getter), move(setter)));
 }
@@ -112,7 +112,7 @@ void Object::visit_children(Cell::Visitor& visitor)
         visitor.visit(it.value);
 }
 
-bool Object::has_own_property(const String& property_name) const
+bool Object::has_own_property(const FlyString& property_name) const
 {
     return m_properties.get(property_name).has_value();
 }
diff --git a/Libraries/LibJS/Runtime/Object.h b/Libraries/LibJS/Runtime/Object.h
index 9e61676c51..fd98b0e44f 100644
--- a/Libraries/LibJS/Runtime/Object.h
+++ b/Libraries/LibJS/Runtime/Object.h
@@ -40,14 +40,14 @@ public:
     Object();
     virtual ~Object();
 
-    Value get(const String& property_name) const;
-    void put(const String& property_name, Value);
+    Value get(const FlyString& property_name) const;
+    void put(const FlyString& property_name, Value);
 
-    virtual Optional<Value> get_own_property(const String& property_name) const;
-    virtual bool put_own_property(const String& property_name, Value);
+    virtual Optional<Value> get_own_property(const FlyString& property_name) const;
+    virtual bool put_own_property(const FlyString& property_name, Value);
 
-    void put_native_function(String property_name, AK::Function<Value(Object*, Vector<Value>)>);
-    void put_native_property(String property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter);
+    void put_native_function(const FlyString& property_name, AK::Function<Value(Object*, Vector<Value>)>);
+    void put_native_property(const FlyString& property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter);
 
     virtual bool is_array() const { return false; }
     virtual bool is_function() const { return false; }
@@ -62,7 +62,7 @@ public:
     const Object* prototype() const { return m_prototype; }
     void set_prototype(Object* prototype) { m_prototype = prototype; }
 
-    bool has_own_property(const String& property_name) const;
+    bool has_own_property(const FlyString& property_name) const;
     enum class PreferredType {
         Default,
         String,
@@ -74,7 +74,7 @@ public:
     virtual Value to_string() const;
 
 private:
-    HashMap<String, Value> m_properties;
+    HashMap<FlyString, Value> m_properties;
     Object* m_prototype { nullptr };
 };
 
diff --git a/Libraries/LibJS/Runtime/ScriptFunction.cpp b/Libraries/LibJS/Runtime/ScriptFunction.cpp
index b7a766bfe3..98883d7587 100644
--- a/Libraries/LibJS/Runtime/ScriptFunction.cpp
+++ b/Libraries/LibJS/Runtime/ScriptFunction.cpp
@@ -31,7 +31,7 @@
 
 namespace JS {
 
-ScriptFunction::ScriptFunction(const ScopeNode& body, Vector<String> parameters)
+ScriptFunction::ScriptFunction(const ScopeNode& body, Vector<FlyString> parameters)
     : m_body(body)
     , m_parameters(move(parameters))
 {
diff --git a/Libraries/LibJS/Runtime/ScriptFunction.h b/Libraries/LibJS/Runtime/ScriptFunction.h
index 4d3fc4b2c1..b5799798fd 100644
--- a/Libraries/LibJS/Runtime/ScriptFunction.h
+++ b/Libraries/LibJS/Runtime/ScriptFunction.h
@@ -32,11 +32,11 @@ namespace JS {
 
 class ScriptFunction final : public Function {
 public:
-    ScriptFunction(const ScopeNode& body, Vector<String> parameters = {});
+    ScriptFunction(const ScopeNode& body, Vector<FlyString> parameters = {});
     virtual ~ScriptFunction();
 
     const ScopeNode& body() const { return m_body; }
-    const Vector<String>& parameters() const { return m_parameters; };
+    const Vector<FlyString>& parameters() const { return m_parameters; };
 
     virtual Value call(Interpreter&, const Vector<Value>&) override;
 
@@ -45,7 +45,7 @@ private:
     virtual const char* class_name() const override { return "ScriptFunction"; }
 
     NonnullRefPtr<ScopeNode> m_body;
-    const Vector<String> m_parameters;
+    const Vector<FlyString> m_parameters;
 };
 
 }
diff --git a/Libraries/LibWeb/Bindings/CanvasRenderingContext2DWrapper.cpp b/Libraries/LibWeb/Bindings/CanvasRenderingContext2DWrapper.cpp
index 5944001880..a5c6a576e4 100644
--- a/Libraries/LibWeb/Bindings/CanvasRenderingContext2DWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/CanvasRenderingContext2DWrapper.cpp
@@ -25,6 +25,7 @@
  */
 
 #include <AK/Function.h>
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/PrimitiveString.h>
 #include <LibJS/Runtime/Value.h>
 #include <LibWeb/Bindings/CanvasRenderingContext2DWrapper.h>
diff --git a/Libraries/LibWeb/Bindings/DocumentWrapper.cpp b/Libraries/LibWeb/Bindings/DocumentWrapper.cpp
index 8d9dcfa295..737a8dca66 100644
--- a/Libraries/LibWeb/Bindings/DocumentWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/DocumentWrapper.cpp
@@ -24,6 +24,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/PrimitiveString.h>
 #include <LibJS/Runtime/Value.h>
 #include <LibWeb/Bindings/DocumentWrapper.h>
diff --git a/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp b/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp
index 972f7d524a..452be45599 100644
--- a/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp
@@ -25,6 +25,7 @@
  */
 
 #include <AK/Function.h>
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/Function.h>
 #include <LibWeb/Bindings/EventListenerWrapper.h>
 #include <LibWeb/Bindings/EventTargetWrapper.h>
diff --git a/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp b/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp
index 8ffcc4f77c..8b99dc3768 100644
--- a/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp
@@ -25,6 +25,7 @@
  */
 
 #include <AK/Function.h>
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/PrimitiveString.h>
 #include <LibJS/Runtime/Value.h>
 #include <LibWeb/Bindings/CanvasRenderingContext2DWrapper.h>
diff --git a/Libraries/LibWeb/Bindings/MouseEventWrapper.cpp b/Libraries/LibWeb/Bindings/MouseEventWrapper.cpp
index c3d652589a..f002d50732 100644
--- a/Libraries/LibWeb/Bindings/MouseEventWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/MouseEventWrapper.cpp
@@ -25,6 +25,7 @@
  */
 
 #include <AK/Function.h>
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/Function.h>
 #include <LibWeb/Bindings/MouseEventWrapper.h>
 #include <LibWeb/DOM/MouseEvent.h>
diff --git a/Libraries/LibWeb/Bindings/NodeWrapper.cpp b/Libraries/LibWeb/Bindings/NodeWrapper.cpp
index aeb84b4e3d..badf650cc0 100644
--- a/Libraries/LibWeb/Bindings/NodeWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/NodeWrapper.cpp
@@ -24,6 +24,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <AK/FlyString.h>
 #include <LibJS/Runtime/PrimitiveString.h>
 #include <LibJS/Runtime/Value.h>
 #include <LibWeb/Bindings/DocumentWrapper.h>