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

pkg/compiler/lib/src/types/dictionary_type_mask.dart

-// Copyright (c) 2014, 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 types;
-
-/**
- * A [DictionaryTypeMask] is a [TypeMask] for a specific allocation
- * site of a map (currently only internal Map class) that is used as
- * a dictionary, i.e. a mapping from a set of statically known strings
- * to values. These typemasks only come into existence after the
- * [TypeGraphInferrer] has successfully identified such a usage. Otherwise,
- * the more general [MapTypeMask] is used.
- */
-class DictionaryTypeMask extends MapTypeMask {
-  // The underlying key/value map of this dictionary.
-  final Map<String, TypeMask> typeMap;
-
-  DictionaryTypeMask(forwardTo,
-                     allocationNode,
-                     allocationElement,
-                     keyType, valueType,
-                     this.typeMap) :
-      super(forwardTo, allocationNode, allocationElement, keyType, valueType);
-
-  TypeMask nullable() {
-    return isNullable
-        ? this
-        : new DictionaryTypeMask(forwardTo.nullable(),
-                                 allocationNode,
-                                 allocationElement,
-                                 keyType, valueType,
-                                 typeMap);
-  }
-
-  TypeMask nonNullable() {
-    return isNullable
-        ? new DictionaryTypeMask(forwardTo.nonNullable(),
-                                 allocationNode,
-                                 allocationElement,
-                                 keyType, valueType,
-                                 typeMap)
-        : this;
-  }
-
-  bool get isDictionary => true;
-  bool get isExact => true;
-
-  bool equalsDisregardNull(other) {
-    if (other is! DictionaryTypeMask) return false;
-    return allocationNode == other.allocationNode &&
-           keyType == other.keyType &&
-           valueType == other.valueType &&
-           typeMap.keys.every((k) => other.typeMap.containsKey(k)) &&
-           other.typeMap.keys.every((k) => typeMap.containsKey(k) &&
-                                           typeMap[k] == other.typeMap[k]);
-
-  }
-
-  TypeMask intersection(TypeMask other, ClassWorld classWorld) {
-    TypeMask forwardIntersection = forwardTo.intersection(other, classWorld);
-    if (forwardIntersection.isEmpty) return forwardIntersection;
-    return forwardIntersection.isNullable
-        ? nullable()
-        : nonNullable();
-  }
-
-  TypeMask union(other, ClassWorld classWorld) {
-    if (this == other) {
-      return this;
-    } else if (equalsDisregardNull(other)) {
-      return other.isNullable ? other : this;
-    } else if (other.isEmpty) {
-      return other.isNullable ? this.nullable() : this;
-    } else if (other.isDictionary) {
-      TypeMask newForwardTo = forwardTo.union(other.forwardTo, classWorld);
-      TypeMask newKeyType = keyType.union(other.keyType, classWorld);
-      TypeMask newValueType = valueType.union(other.valueType, classWorld);
-      Map<String, TypeMask> mappings = <String, TypeMask>{};
-      typeMap.forEach((k,v) {
-              if (!other.typeMap.containsKey(k)) {
-                mappings[k] = v.nullable();
-              }
-            });
-      other.typeMap.forEach((k,v) {
-        if (typeMap.containsKey(k)) {
-          mappings[k] = v.union(typeMap[k], classWorld);
-        } else {
-          mappings[k] = v.nullable();
-        }
-      });
-      return new DictionaryTypeMask(newForwardTo, null, null,
-                                    newKeyType, newValueType, mappings);
-    } else if (other.isMap &&
-               (other.keyType != null) &&
-               (other.valueType != null)) {
-      TypeMask newForwardTo = forwardTo.union(other.forwardTo, classWorld);
-      TypeMask newKeyType = keyType.union(other.keyType, classWorld);
-      TypeMask newValueType = valueType.union(other.valueType, classWorld);
-      return new MapTypeMask(newForwardTo, null, null,
-                             newKeyType, newValueType);
-    } else {
-      return forwardTo.union(other, classWorld);
-    }
-  }
-
-  bool operator==(other) => super == other;
-
-  int get hashCode {
-    return computeHashCode(
-        allocationNode, isNullable, typeMap, forwardTo);
-  }
-
-  String toString() {
-    return
-        'Dictionary mask: [$keyType/$valueType with $typeMap] type: $forwardTo';
-  }
-}