Move constants into their own file.

lib/compiler/implementation/compile_time_constants.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-class Constant implements Hashable {
-  const Constant();
-
-  bool isNull() => false;
-  bool isBool() => false;
-  bool isTrue() => false;
-  bool isFalse() => false;
-  bool isInt() => false;
-  bool isDouble() => false;
-  bool isNum() => false;
-  bool isString() => false;
-  bool isList() => false;
-  bool isMap() => false;
-  bool isConstructedObject() => false;
-  bool isFunction() => false;
-  /** Returns true if the constant is null, a bool, a number or a string. */
-  bool isPrimitive() => false;
-  /** Returns true if the constant is a list, a map or a constructed object. */
-  bool isObject() => false;
-  bool isSentinel() => false;
-
-  bool isNaN() => false;
-  bool isMinusZero() => false;
-
-  abstract void _writeJsCode(CodeBuffer buffer, ConstantHandler handler);
-  /**
-    * Unless the constant can be emitted multiple times (as for numbers and
-    * strings) adds its canonical name to the buffer.
-    */
-  abstract void _writeCanonicalizedJsCode(CodeBuffer buffer,
-                                          ConstantHandler handler);
-  abstract List<Constant> getDependencies();
-}
-
-class SentinelConstant extends Constant {
-  const SentinelConstant();
-  static final SENTINEL = const SentinelConstant();
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    handler.compiler.internalError(
-        "The parameter sentinel constant does not need specific JS code");
-  }
-
-  void _writeCanonicalizedJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add(handler.compiler.namer.CURRENT_ISOLATE);
-  }
-
-  List<Constant> getDependencies() => const <Constant>[];
-
-  // Just use a randome value.
-  int hashCode() => 926429784158;
-
-  bool isSentinel() => true;
-}
-
-class FunctionConstant extends Constant {
-  Element element;
-
-  FunctionConstant(this.element);
-
-  bool isFunction() => true;
-
-  bool operator ==(var other) {
-    if (other is !FunctionConstant) return false;
-    return other.element === element;
-  }
-
-  String toString() => element.toString();
-  List<Constant> getDependencies() => const <Constant>[];
-  DartString toDartString() {
-    return new DartString.literal(element.name.slowToString());
-  }
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    handler.compiler.internalError(
-        "A constant function does not need specific JS code");
-  }
-
-  void _writeCanonicalizedJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add(handler.compiler.namer.isolatePropertiesAccess(element));
-  }
-
-  int hashCode() => (17 * element.hashCode()) & 0x7fffffff;
-}
-
-class PrimitiveConstant extends Constant {
-  abstract get value;
-  const PrimitiveConstant();
-  bool isPrimitive() => true;
-
-  bool operator ==(var other) {
-    if (other is !PrimitiveConstant) return false;
-    PrimitiveConstant otherPrimitive = other;
-    // We use == instead of === so that DartStrings compare correctly.
-    return value == otherPrimitive.value;
-  }
-
-  String toString() => value.toString();
-  // Primitive constants don't have dependencies.
-  List<Constant> getDependencies() => const <Constant>[];
-  abstract DartString toDartString();
-
-  void _writeCanonicalizedJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    _writeJsCode(buffer, handler);
-  }
-}
-
-class NullConstant extends PrimitiveConstant {
-  /** The value a Dart null is compiled to in JavaScript. */
-  static const String JsNull = "null";
-
-  factory NullConstant() => const NullConstant._internal();
-  const NullConstant._internal();
-  bool isNull() => true;
-  get value => null;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add(JsNull);
-  }
-
-  // The magic constant has no meaning. It is just a random value.
-  int hashCode() => 785965825;
-  DartString toDartString() => const LiteralDartString("null");
-}
-
-class NumConstant extends PrimitiveConstant {
-  abstract num get value;
-  const NumConstant();
-  bool isNum() => true;
-}
-
-class IntConstant extends NumConstant {
-  final int value;
-  factory IntConstant(int value) {
-    switch (value) {
-      case 0: return const IntConstant._internal(0);
-      case 1: return const IntConstant._internal(1);
-      case 2: return const IntConstant._internal(2);
-      case 3: return const IntConstant._internal(3);
-      case 4: return const IntConstant._internal(4);
-      case 5: return const IntConstant._internal(5);
-      case 6: return const IntConstant._internal(6);
-      case 7: return const IntConstant._internal(7);
-      case 8: return const IntConstant._internal(8);
-      case 9: return const IntConstant._internal(9);
-      case 10: return const IntConstant._internal(10);
-      case -1: return const IntConstant._internal(-1);
-      case -2: return const IntConstant._internal(-2);
-      default: return new IntConstant._internal(value);
-    }
-  }
-  const IntConstant._internal(this.value);
-  bool isInt() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add("$value");
-  }
-
-  // We have to override the equality operator so that ints and doubles are
-  // treated as separate constants.
-  // The is [:!IntConstant:] check at the beginning of the function makes sure
-  // that we compare only equal to integer constants.
-  bool operator ==(var other) {
-    if (other is !IntConstant) return false;
-    IntConstant otherInt = other;
-    return value == otherInt.value;
-  }
-
-  int hashCode() => value.hashCode();
-  DartString toDartString() => new DartString.literal(value.toString());
-}
-
-class DoubleConstant extends NumConstant {
-  final double value;
-  factory DoubleConstant(double value) {
-    if (value.isNaN()) {
-      return const DoubleConstant._internal(double.NAN);
-    } else if (value == double.INFINITY) {
-      return const DoubleConstant._internal(double.INFINITY);
-    } else if (value == -double.INFINITY) {
-      return const DoubleConstant._internal(-double.INFINITY);
-    } else if (value == 0.0 && !value.isNegative()) {
-      return const DoubleConstant._internal(0.0);
-    } else if (value == 1.0) {
-      return const DoubleConstant._internal(1.0);
-    } else {
-      return new DoubleConstant._internal(value);
-    }
-  }
-  const DoubleConstant._internal(this.value);
-  bool isDouble() => true;
-  bool isNaN() => value.isNaN();
-  // We need to check for the negative sign since -0.0 == 0.0.
-  bool isMinusZero() => value == 0.0 && value.isNegative();
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    if (value.isNaN()) {
-      buffer.add("(0/0)");
-    } else if (value == double.INFINITY) {
-      buffer.add("(1/0)");
-    } else if (value == -double.INFINITY) {
-      buffer.add("(-1/0)");
-    } else {
-      buffer.add("$value");
-    }
-  }
-
-  bool operator ==(var other) {
-    if (other is !DoubleConstant) return false;
-    DoubleConstant otherDouble = other;
-    double otherValue = otherDouble.value;
-    if (value == 0.0 && otherValue == 0.0) {
-      return value.isNegative() == otherValue.isNegative();
-    } else if (value.isNaN()) {
-      return otherValue.isNaN();
-    } else {
-      return value == otherValue;
-    }
-  }
-
-  int hashCode() => value.hashCode();
-  DartString toDartString() => new DartString.literal(value.toString());
-}
-
-class BoolConstant extends PrimitiveConstant {
-  factory BoolConstant(value) {
-    return value ? new TrueConstant() : new FalseConstant();
-  }
-  const BoolConstant._internal();
-  bool isBool() => true;
-
-  abstract BoolConstant negate();
-}
-
-class TrueConstant extends BoolConstant {
-  final bool value = true;
-
-  factory TrueConstant() => const TrueConstant._internal();
-  const TrueConstant._internal() : super._internal();
-  bool isTrue() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add("true");
-  }
-
-  FalseConstant negate() => new FalseConstant();
-
-  bool operator ==(var other) => this === other;
-  // The magic constant is just a random value. It does not have any
-  // significance.
-  int hashCode() => 499;
-  DartString toDartString() => const LiteralDartString("true");
-}
-
-class FalseConstant extends BoolConstant {
-  final bool value = false;
-
-  factory FalseConstant() => const FalseConstant._internal();
-  const FalseConstant._internal() : super._internal();
-  bool isFalse() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add("false");
-  }
-
-  TrueConstant negate() => new TrueConstant();
-
-  bool operator ==(var other) => this === other;
-  // The magic constant is just a random value. It does not have any
-  // significance.
-  int hashCode() => 536555975;
-  DartString toDartString() => const LiteralDartString("false");
-}
-
-class StringConstant extends PrimitiveConstant {
-  final DartString value;
-  int _hashCode;
-  final Node node;
-
-  StringConstant(this.value, this.node) {
-    // TODO(floitsch): cache StringConstants.
-    // TODO(floitsch): compute hashcode without calling toString() on the
-    // DartString.
-    _hashCode = value.slowToString().hashCode();
-  }
-  bool isString() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add("'");
-    ConstantHandler.writeEscapedString(value, buffer, (reason) {
-      handler.compiler.reportError(node, reason);
-    });
-    buffer.add("'");
-  }
-
-  bool operator ==(var other) {
-    if (other is !StringConstant) return false;
-    StringConstant otherString = other;
-    return (_hashCode == otherString._hashCode) && (value == otherString.value);
-  }
-
-  int hashCode() => _hashCode;
-  DartString toDartString() => value;
-  int get length => value.length;
-}
-
-class ObjectConstant extends Constant {
-  final DartType type;
-
-  ObjectConstant(this.type);
-  bool isObject() => true;
-
-  // TODO(1603): The class should be marked as abstract, but the VM doesn't
-  // currently allow this.
-  abstract int hashCode();
-
-  void _writeCanonicalizedJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    String name = handler.getNameForConstant(this);
-    buffer.add(handler.compiler.namer.isolatePropertiesAccessForConstant(name));
-  }
-}
-
-class ListConstant extends ObjectConstant {
-  final List<Constant> entries;
-  int _hashCode;
-
-  ListConstant(DartType type, this.entries) : super(type) {
-    // TODO(floitsch): create a better hash.
-    int hash = 0;
-    for (Constant input in entries) hash ^= input.hashCode();
-    _hashCode = hash;
-  }
-  bool isList() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    // TODO(floitsch): we should not need to go through the compiler to make
-    // the list constant.
-    buffer.add("${handler.compiler.namer.ISOLATE}.makeConstantList");
-    buffer.add("([");
-    for (int i = 0; i < entries.length; i++) {
-      if (i != 0) buffer.add(", ");
-      Constant entry = entries[i];
-      handler.writeConstant(buffer, entry);
-    }
-    buffer.add("])");
-  }
-
-  bool operator ==(var other) {
-    if (other is !ListConstant) return false;
-    ListConstant otherList = other;
-    if (hashCode() != otherList.hashCode()) return false;
-    // TODO(floitsch): verify that the generic types are the same.
-    if (entries.length != otherList.entries.length) return false;
-    for (int i = 0; i < entries.length; i++) {
-      if (entries[i] != otherList.entries[i]) return false;
-    }
-    return true;
-  }
-
-  int hashCode() => _hashCode;
-
-  List<Constant> getDependencies() => entries;
-
-  int get length => entries.length;
-}
-
-class MapConstant extends ObjectConstant {
-  /**
-   * The [PROTO_PROPERTY] must not be used as normal property in any JavaScript
-   * object. It would change the prototype chain.
-   */
-  static const String PROTO_PROPERTY = "__proto__";
-
-  /** The dart class implementing constant map literals. */
-  static const SourceString DART_CLASS = const SourceString("ConstantMap");
-  static const SourceString DART_PROTO_CLASS =
-      const SourceString("ConstantProtoMap");
-  static const SourceString LENGTH_NAME = const SourceString("length");
-  static const SourceString JS_OBJECT_NAME = const SourceString("_jsObject");
-  static const SourceString KEYS_NAME = const SourceString("_keys");
-  static const SourceString PROTO_VALUE = const SourceString("_protoValue");
-
-  final ListConstant keys;
-  final List<Constant> values;
-  final Constant protoValue;
-  int _hashCode;
-
-  MapConstant(DartType type, this.keys, this.values, this.protoValue)
-      : super(type) {
-    // TODO(floitsch): create a better hash.
-    int hash = 0;
-    for (Constant value in values) hash ^= value.hashCode();
-    _hashCode = hash;
-  }
-  bool isMap() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-
-    void writeJsMap() {
-      buffer.add("{");
-      int valueIndex = 0;
-      for (int i = 0; i < keys.entries.length; i++) {
-        StringConstant key = keys.entries[i];
-        if (key.value == const LiteralDartString(PROTO_PROPERTY)) continue;
-
-        if (valueIndex != 0) buffer.add(", ");
-
-        key._writeJsCode(buffer, handler);
-        buffer.add(": ");
-        Constant value = values[valueIndex++];
-        handler.writeConstant(buffer, value);
-      }
-      buffer.add("}");
-      if (valueIndex != values.length) {
-        handler.compiler.internalError("Bad value count.");
-      }
-    }
-
-    void badFieldCountError() {
-      handler.compiler.internalError(
-          "Compiler and ConstantMap disagree on number of fields.");
-    }
-
-    ClassElement classElement = type.element;
-    buffer.add("new ");
-    buffer.add(handler.getJsConstructor(classElement));
-    buffer.add("(");
-    // The arguments of the JavaScript constructor for any given Dart class
-    // are in the same order as the members of the class element.
-    int emittedArgumentCount = 0;
-    classElement.forEachInstanceField(
-        includeBackendMembers: true,
-        includeSuperMembers: true,
-        f: (ClassElement enclosing, Element field) {
-      if (emittedArgumentCount != 0) buffer.add(", ");
-      if (field.name == LENGTH_NAME) {
-        buffer.add(keys.entries.length);
-      } else if (field.name == JS_OBJECT_NAME) {
-        writeJsMap();
-      } else if (field.name == KEYS_NAME) {
-        handler.writeConstant(buffer, keys);
-      } else if (field.name == PROTO_VALUE) {
-        assert(protoValue !== null);
-        handler.writeConstant(buffer, protoValue);
-      } else {
-        badFieldCountError();
-      }
-      emittedArgumentCount++;
-    });
-    if ((protoValue === null && emittedArgumentCount != 3) ||
-        (protoValue !== null && emittedArgumentCount != 4)) {
-      badFieldCountError();
-    }
-    buffer.add(")");
-  }
-
-  bool operator ==(var other) {
-    if (other is !MapConstant) return false;
-    MapConstant otherMap = other;
-    if (hashCode() != otherMap.hashCode()) return false;
-    // TODO(floitsch): verify that the generic types are the same.
-    if (keys != otherMap.keys) return false;
-    for (int i = 0; i < values.length; i++) {
-      if (values[i] != otherMap.values[i]) return false;
-    }
-    return true;
-  }
-
-  int hashCode() => _hashCode;
-
-  List<Constant> getDependencies() {
-    List<Constant> result = <Constant>[keys];
-    result.addAll(values);
-    return result;
-  }
-
-  int get length => keys.length;
-}
-
-class ConstructedConstant extends ObjectConstant {
-  final List<Constant> fields;
-  int _hashCode;
-
-  ConstructedConstant(DartType type, this.fields) : super(type) {
-    assert(type !== null);
-    // TODO(floitsch): create a better hash.
-    int hash = 0;
-    for (Constant field in fields) {
-      hash ^= field.hashCode();
-    }
-    hash ^= type.element.hashCode();
-    _hashCode = hash;
-  }
-  bool isConstructedObject() => true;
-
-  void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
-    buffer.add("new ");
-    buffer.add(handler.getJsConstructor(type.element));
-    buffer.add("(");
-    for (int i = 0; i < fields.length; i++) {
-      if (i != 0) buffer.add(", ");
-      Constant field = fields[i];
-      handler.writeConstant(buffer, field);
-    }
-    buffer.add(")");
-  }
-
-  bool operator ==(var otherVar) {
-    if (otherVar is !ConstructedConstant) return false;
-    ConstructedConstant other = otherVar;
-    if (hashCode() != other.hashCode()) return false;
-    // TODO(floitsch): verify that the (generic) types are the same.
-    if (type.element != other.type.element) return false;
-    if (fields.length != other.fields.length) return false;
-    for (int i = 0; i < fields.length; i++) {
-      if (fields[i] != other.fields[i]) return false;
-    }
-    return true;
-  }
-
-  int hashCode() => _hashCode;
-  List<Constant> getDependencies() => fields;
-}
-
 /**
  * The [ConstantHandler] keeps track of compile-time constants,
  * initializations of global and static fields, and default values of
  * optional parameters.
  */
 class ConstantHandler extends CompilerTask {
   final ConstantSystem constantSystem;
 
   /**
    * Contains the initial value of fields. Must contain all static and global
@@ skipping 800 matching lines @@
       Constant fieldValue = fieldValues[field];
       if (fieldValue === null) {
         // Use the default value.
         fieldValue = compiler.compileConstant(field);
       }
       jsNewArguments.add(fieldValue);
     });
     return jsNewArguments;
   }
 }