Revert "Move dart2js from sdk/lib/_internal/compiler to pkg/compiler"

pkg/compiler/lib/src/constant_system.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.
-
-part of dart2js;
-
-abstract class Operation {
-  String get name;
-}
-
-abstract class UnaryOperation extends Operation {
-  /** Returns [:null:] if it was unable to fold the operation. */
-  ConstantValue fold(ConstantValue constant);
-}
-
-abstract class BinaryOperation extends Operation {
-  /** Returns [:null:] if it was unable to fold the operation. */
-  ConstantValue fold(ConstantValue left, ConstantValue right);
-  apply(left, right);
-}
-
-/**
- * A [ConstantSystem] is responsible for creating constants and folding them.
- */
-abstract class ConstantSystem {
-  BinaryOperation get add;
-  BinaryOperation get bitAnd;
-  UnaryOperation get bitNot;
-  BinaryOperation get bitOr;
-  BinaryOperation get bitXor;
-  BinaryOperation get booleanAnd;
-  BinaryOperation get booleanOr;
-  BinaryOperation get divide;
-  BinaryOperation get equal;
-  BinaryOperation get greaterEqual;
-  BinaryOperation get greater;
-  BinaryOperation get identity;
-  BinaryOperation get lessEqual;
-  BinaryOperation get less;
-  BinaryOperation get modulo;
-  BinaryOperation get multiply;
-  UnaryOperation get negate;
-  UnaryOperation get not;
-  BinaryOperation get shiftLeft;
-  BinaryOperation get shiftRight;
-  BinaryOperation get subtract;
-  BinaryOperation get truncatingDivide;
-
-  BinaryOperation get codeUnitAt;
-
-  const ConstantSystem();
-
-  ConstantValue createInt(int i);
-  ConstantValue createDouble(double d);
-  ConstantValue createString(DartString string);
-  ConstantValue createBool(bool value);
-  ConstantValue createNull();
-  ConstantValue createMap(Compiler compiler,
-                          InterfaceType type,
-                          List<ConstantValue> keys,
-                          List<ConstantValue> values);
-
-  // We need to special case the subtype check for JavaScript constant
-  // system because an int is a double at runtime.
-  bool isSubtype(Compiler compiler, DartType s, DartType t);
-
-  /** Returns true if the [constant] is an integer at runtime. */
-  bool isInt(ConstantValue constant);
-  /** Returns true if the [constant] is a double at runtime. */
-  bool isDouble(ConstantValue constant);
-  /** Returns true if the [constant] is a string at runtime. */
-  bool isString(ConstantValue constant);
-  /** Returns true if the [constant] is a boolean at runtime. */
-  bool isBool(ConstantValue constant);
-  /** Returns true if the [constant] is null at runtime. */
-  bool isNull(ConstantValue constant);
-
-  UnaryOperation lookupUnary(String operator) {
-    switch (operator) {
-      case '~': return bitNot;
-      case '-': return negate;
-      case '!': return not;
-      default:  return null;
-    }
-  }
-
-  BinaryOperation lookupBinary(String operator) {
-    switch (operator) {
-      case "+":   return add;
-      case "-":   return subtract;
-      case "*":   return multiply;
-      case "/":   return divide;
-      case "%":   return modulo;
-      case "~/":  return truncatingDivide;
-      case "|":   return bitOr;
-      case "&":   return bitAnd;
-      case "^":   return bitXor;
-      case "||":  return booleanOr;
-      case "&&":  return booleanAnd;
-      case "<<":  return shiftLeft;
-      case ">>":  return shiftRight;
-      case "<":   return less;
-      case "<=":  return lessEqual;
-      case ">":   return greater;
-      case ">=":  return greaterEqual;
-      case "==":  return equal;
-      default:    return null;
-    }
-  }
-}