| // Copyright (c) 2013, 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 [ContainerTypeMask] is a [TypeMask] for a specific allocation |
| /// site of a container (currently only List) that will get specialized |
| /// once the [TypeGraphInferrer] phase finds an element type for it. |
| class ContainerTypeMask extends ForwardingTypeMask { |
| final TypeMask forwardTo; |
| |
| // The [Node] where this type mask was created. |
| final Node allocationNode; |
| |
| // The [Element] where this type mask was created. |
| final Element allocationElement; |
| |
| // The element type of this container. |
| final TypeMask elementType; |
| |
| // The length of the container. |
| final int length; |
| |
| ContainerTypeMask(this.forwardTo, |
| this.allocationNode, |
| this.allocationElement, |
| this.elementType, |
| this.length); |
| |
| TypeMask nullable() { |
| return isNullable |
| ? this |
| : new ContainerTypeMask(forwardTo.nullable(), |
| allocationNode, |
| allocationElement, |
| elementType, |
| length); |
| } |
| |
| TypeMask nonNullable() { |
| return isNullable |
| ? new ContainerTypeMask(forwardTo.nonNullable(), |
| allocationNode, |
| allocationElement, |
| elementType, |
| length) |
| : this; |
| } |
| |
| bool get isContainer => true; |
| bool get isExact => true; |
| |
| bool equalsDisregardNull(other) { |
| if (other is! ContainerTypeMask) return false; |
| return allocationNode == other.allocationNode |
| && elementType == other.elementType |
| && length == other.length; |
| } |
| |
| TypeMask intersection(TypeMask other, Compiler compiler) { |
| TypeMask forwardIntersection = forwardTo.intersection(other, compiler); |
| if (forwardIntersection.isEmpty) return forwardIntersection; |
| return forwardIntersection.isNullable |
| ? nullable() |
| : nonNullable(); |
| } |
| |
| TypeMask union(other, Compiler compiler) { |
| 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.isContainer |
| && elementType != null |
| && other.elementType != null) { |
| TypeMask newElementType = |
| elementType.union(other.elementType, compiler); |
| int newLength = (length == other.length) ? length : null; |
| TypeMask newForwardTo = forwardTo.union(other.forwardTo, compiler); |
| return new ContainerTypeMask( |
| newForwardTo, null, null, newElementType, newLength); |
| } else { |
| return forwardTo.union(other, compiler); |
| } |
| } |
| |
| bool operator==(other) { |
| if (other is! ContainerTypeMask) return false; |
| return allocationNode == other.allocationNode |
| && isNullable == other.isNullable |
| && elementType == other.elementType |
| && length == other.length; |
| } |
| |
| int get hashCode { |
| return computeHashCode(allocationNode, isNullable, elementType, length); |
| } |
| |
| String toString() { |
| return 'Container mask: $elementType'; |
| } |
| } |