| // 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. |
| |
| library dart_types; |
| |
| import 'dart2jslib.dart' show Compiler, invariant, Script, Message; |
| import 'elements/modelx.dart' |
| show VoidElementX, LibraryElementX, BaseClassElementX; |
| import 'elements/elements.dart'; |
| import 'scanner/scannerlib.dart' show SourceString; |
| import 'util/util.dart' show Link, LinkBuilder; |
| |
| class TypeKind { |
| final String id; |
| |
| const TypeKind(String this.id); |
| |
| static const TypeKind FUNCTION = const TypeKind('function'); |
| static const TypeKind INTERFACE = const TypeKind('interface'); |
| static const TypeKind STATEMENT = const TypeKind('statement'); |
| static const TypeKind TYPEDEF = const TypeKind('typedef'); |
| static const TypeKind TYPE_VARIABLE = const TypeKind('type variable'); |
| static const TypeKind MALFORMED_TYPE = const TypeKind('malformed'); |
| static const TypeKind VOID = const TypeKind('void'); |
| |
| String toString() => id; |
| } |
| |
| abstract class DartType { |
| SourceString get name; |
| |
| TypeKind get kind; |
| |
| const DartType(); |
| |
| /** |
| * Returns the [Element] which declared this type. |
| * |
| * This can be [ClassElement] for classes, [TypedefElement] for typedefs, |
| * [TypeVariableElement] for type variables and [FunctionElement] for |
| * function types. |
| * |
| * Invariant: [element] must be a declaration element. |
| */ |
| Element get element; |
| |
| /** |
| * Performs the substitution [: [arguments[i]/parameters[i]]this :]. |
| * |
| * The notation is known from this lambda calculus rule: |
| * |
| * (lambda x.e0)e1 -> [e1/x]e0. |
| * |
| * See [TypeVariableType] for a motivation for this method. |
| * |
| * Invariant: There must be the same number of [arguments] and [parameters]. |
| */ |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters); |
| |
| /** |
| * Returns the unaliased type of this type. |
| * |
| * The unaliased type of a typedef'd type is the unaliased type to which its |
| * name is bound. The unaliased version of any other type is the type itself. |
| * |
| * For example, the unaliased type of [: typedef A Func<A,B>(B b) :] is the |
| * function type [: (B) -> A :] and the unaliased type of |
| * [: Func<int,String> :] is the function type [: (String) -> int :]. |
| */ |
| DartType unalias(Compiler compiler); |
| |
| /** |
| * Finds the method, field or property named [name] declared or inherited |
| * on this type. |
| */ |
| // TODO(johnniwinther): Implement this for [TypeVariableType], [FunctionType], |
| // and [TypedefType]. |
| Member lookupMember(SourceString name) => null; |
| |
| /** |
| * A type is malformed if it is itself a malformed type or contains a |
| * malformed type. |
| */ |
| bool get isMalformed => false; |
| |
| /** |
| * Calls [f] with each [MalformedType] within this type. |
| * |
| * If [f] returns [: false :], the traversal stops prematurely. |
| * |
| * [forEachMalformedType] returns [: false :] if the traversal was stopped |
| * prematurely. |
| */ |
| bool forEachMalformedType(bool f(MalformedType type)) => true; |
| |
| bool operator ==(other); |
| |
| /** |
| * Is [: true :] if this type has no explict type arguments. |
| */ |
| bool get isRaw => true; |
| |
| DartType asRaw() => this; |
| |
| /** |
| * Is [: true :] if this type is the dynamic type. |
| */ |
| bool get isDynamic => false; |
| |
| /** |
| * Is [: true :] if this type is the void type. |
| */ |
| bool get isVoid => false; |
| |
| /** |
| * Returns an occurrence of a type variable within this type, if any. |
| */ |
| TypeVariableType get typeVariableOccurrence => null; |
| |
| TypeVariableType _findTypeVariableOccurrence(Link<DartType> types) { |
| for (Link<DartType> link = types; !link.isEmpty ; link = link.tail) { |
| TypeVariableType typeVariable = link.head.typeVariableOccurrence; |
| if (typeVariable != null) { |
| return typeVariable; |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Is [: true :] if this type contains any type variables. |
| */ |
| bool get containsTypeVariables => typeVariableOccurrence != null; |
| |
| accept(DartTypeVisitor visitor, var argument); |
| |
| void visitChildren(DartTypeVisitor visitor, var argument) {} |
| |
| static void visitList(Link<DartType> types, |
| DartTypeVisitor visitor, var argument) { |
| for (Link<DartType> link = types; !link.isEmpty ; link = link.tail) { |
| link.head.accept(visitor, argument); |
| } |
| } |
| } |
| |
| /** |
| * Represents a type variable, that is the type parameters of a class type. |
| * |
| * For example, in [: class Array<E> { ... } :], E is a type variable. |
| * |
| * Each class should have its own unique type variables, one for each type |
| * parameter. A class with type parameters is said to be parameterized or |
| * generic. |
| * |
| * Non-static members, constructors, and factories of generic |
| * class/interface can refer to type variables of the current class |
| * (not of supertypes). |
| * |
| * When using a generic type, also known as an application or |
| * instantiation of the type, the actual type arguments should be |
| * substituted for the type variables in the class declaration. |
| * |
| * For example, given a box, [: class Box<T> { T value; } :], the |
| * type of the expression [: new Box<String>().value :] is |
| * [: String :] because we must substitute [: String :] for the |
| * the type variable [: T :]. |
| */ |
| class TypeVariableType extends DartType { |
| final TypeVariableElement element; |
| |
| TypeVariableType(this.element); |
| |
| TypeKind get kind => TypeKind.TYPE_VARIABLE; |
| |
| SourceString get name => element.name; |
| |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters) { |
| if (parameters.isEmpty) { |
| assert(arguments.isEmpty); |
| // Return fast on empty substitutions. |
| return this; |
| } |
| Link<DartType> parameterLink = parameters; |
| Link<DartType> argumentLink = arguments; |
| while (!argumentLink.isEmpty && !parameterLink.isEmpty) { |
| TypeVariableType parameter = parameterLink.head; |
| DartType argument = argumentLink.head; |
| if (parameter == this) { |
| assert(argumentLink.tail.isEmpty == parameterLink.tail.isEmpty); |
| return argument; |
| } |
| parameterLink = parameterLink.tail; |
| argumentLink = argumentLink.tail; |
| } |
| assert(argumentLink.isEmpty && parameterLink.isEmpty); |
| // The type variable was not substituted. |
| return this; |
| } |
| |
| DartType unalias(Compiler compiler) => this; |
| |
| DartType get typeVariableOccurrence => this; |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitTypeVariableType(this, argument); |
| } |
| |
| int get hashCode => 17 * element.hashCode; |
| |
| bool operator ==(other) { |
| if (other is !TypeVariableType) return false; |
| return identical(other.element, element); |
| } |
| |
| String toString() => name.slowToString(); |
| } |
| |
| /** |
| * A statement type tracks whether a statement returns or may return. |
| */ |
| class StatementType extends DartType { |
| final String stringName; |
| |
| Element get element => null; |
| |
| TypeKind get kind => TypeKind.STATEMENT; |
| |
| SourceString get name => new SourceString(stringName); |
| |
| const StatementType(this.stringName); |
| |
| static const RETURNING = const StatementType('<returning>'); |
| static const NOT_RETURNING = const StatementType('<not returning>'); |
| static const MAYBE_RETURNING = const StatementType('<maybe returning>'); |
| |
| /** Combine the information about two control-flow edges that are joined. */ |
| StatementType join(StatementType other) { |
| return (identical(this, other)) ? this : MAYBE_RETURNING; |
| } |
| |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters) { |
| // Statement types are not substitutable. |
| return this; |
| } |
| |
| DartType unalias(Compiler compiler) => this; |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitStatementType(this, argument); |
| } |
| |
| int get hashCode => 17 * stringName.hashCode; |
| |
| bool operator ==(other) { |
| if (other is !StatementType) return false; |
| return other.stringName == stringName; |
| } |
| |
| String toString() => stringName; |
| } |
| |
| class VoidType extends DartType { |
| const VoidType(this.element); |
| |
| TypeKind get kind => TypeKind.VOID; |
| |
| SourceString get name => element.name; |
| |
| final Element element; |
| |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters) { |
| // Void cannot be substituted. |
| return this; |
| } |
| |
| DartType unalias(Compiler compiler) => this; |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitVoidType(this, argument); |
| } |
| |
| bool get isVoid => true; |
| |
| int get hashCode => 1729; |
| |
| bool operator ==(other) => other is VoidType; |
| |
| String toString() => name.slowToString(); |
| } |
| |
| class MalformedType extends DartType { |
| final ErroneousElement element; |
| |
| /** |
| * [declaredType] holds the type which the user wrote in code. |
| * |
| * For instance, for a resolved but malformed type like [: Map<String> :] the |
| * [declaredType] is [: Map<String> :] whereas for an unresolved type |
| * [userProvidedBadType] is [: null :]. |
| */ |
| final DartType userProvidedBadType; |
| |
| /** |
| * Type arguments for the malformed typed, if these cannot fit in the |
| * [declaredType]. |
| * |
| * This field is for instance used for [: dynamic<int> :] and [: T<int> :] |
| * where [: T :] is a type variable, in which case [declaredType] holds |
| * [: dynamic :] and [: T :], respectively, or for [: X<int> :] where [: X :] |
| * is not resolved or does not imply a type. |
| */ |
| final Link<DartType> typeArguments; |
| |
| MalformedType(this.element, this.userProvidedBadType, |
| [this.typeArguments = null]); |
| |
| TypeKind get kind => TypeKind.MALFORMED_TYPE; |
| |
| SourceString get name => element.name; |
| |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters) { |
| // Malformed types are not substitutable. |
| return this; |
| } |
| |
| bool get isMalformed => true; |
| |
| bool forEachMalformedType(bool f(MalformedType type)) => f(this); |
| |
| DartType unalias(Compiler compiler) => this; |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitMalformedType(this, argument); |
| } |
| |
| String toString() { |
| var sb = new StringBuffer(); |
| if (typeArguments != null) { |
| if (userProvidedBadType != null) { |
| sb.write(userProvidedBadType.name.slowToString()); |
| } else { |
| sb.write(element.name.slowToString()); |
| } |
| if (!typeArguments.isEmpty) { |
| sb.write('<'); |
| typeArguments.printOn(sb, ', '); |
| sb.write('>'); |
| } |
| } else { |
| sb.write(userProvidedBadType.toString()); |
| } |
| return sb.toString(); |
| } |
| } |
| |
| bool hasMalformed(Link<DartType> types) { |
| for (DartType typeArgument in types) { |
| if (typeArgument.isMalformed) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| abstract class GenericType extends DartType { |
| final Link<DartType> typeArguments; |
| final bool isMalformed; |
| |
| GenericType(Link<DartType> this.typeArguments, bool this.isMalformed); |
| |
| TypeDeclarationElement get element; |
| |
| /// Creates a new instance of this type using the provided type arguments. |
| GenericType _createType(Link<DartType> newTypeArguments); |
| |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters) { |
| if (typeArguments.isEmpty) { |
| // Return fast on non-generic types. |
| return this; |
| } |
| if (parameters.isEmpty) { |
| assert(arguments.isEmpty); |
| // Return fast on empty substitutions. |
| return this; |
| } |
| Link<DartType> newTypeArguments = |
| Types.substTypes(typeArguments, arguments, parameters); |
| if (!identical(typeArguments, newTypeArguments)) { |
| // Create a new type only if necessary. |
| return _createType(newTypeArguments); |
| } |
| return this; |
| } |
| |
| bool forEachMalformedType(bool f(MalformedType type)) { |
| for (DartType typeArgument in typeArguments) { |
| if (!typeArgument.forEachMalformedType(f)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| TypeVariableType get typeVariableOccurrence { |
| return _findTypeVariableOccurrence(typeArguments); |
| } |
| |
| void visitChildren(DartTypeVisitor visitor, var argument) { |
| DartType.visitList(typeArguments, visitor, argument); |
| } |
| |
| String toString() { |
| StringBuffer sb = new StringBuffer(); |
| sb.write(name.slowToString()); |
| if (!isRaw) { |
| sb.write('<'); |
| typeArguments.printOn(sb, ', '); |
| sb.write('>'); |
| } |
| return sb.toString(); |
| } |
| |
| int get hashCode { |
| int hash = element.hashCode; |
| for (Link<DartType> arguments = this.typeArguments; |
| !arguments.isEmpty; |
| arguments = arguments.tail) { |
| int argumentHash = arguments.head != null ? arguments.head.hashCode : 0; |
| hash = 17 * hash + 3 * argumentHash; |
| } |
| return hash; |
| } |
| |
| bool operator ==(other) { |
| if (!identical(element, other.element)) return false; |
| return typeArguments == other.typeArguments; |
| } |
| |
| bool get isRaw => typeArguments.isEmpty || identical(this, element.rawType); |
| |
| GenericType asRaw() => element.rawType; |
| } |
| |
| // TODO(johnniwinther): Add common supertype for InterfaceType and TypedefType. |
| class InterfaceType extends GenericType { |
| final ClassElement element; |
| |
| InterfaceType(this.element, |
| [Link<DartType> typeArguments = const Link<DartType>()]) |
| : super(typeArguments, hasMalformed(typeArguments)) { |
| assert(invariant(element, element.isDeclaration)); |
| assert(invariant(element, element.thisType == null || |
| typeArguments.slowLength() == element.typeVariables.slowLength(), |
| message: () => 'Invalid type argument count on ${element.thisType}. ' |
| 'Provided type arguments: $typeArguments.')); |
| } |
| |
| InterfaceType.userProvidedBadType(this.element, |
| [Link<DartType> typeArguments = |
| const Link<DartType>()]) |
| : super(typeArguments, true); |
| |
| TypeKind get kind => TypeKind.INTERFACE; |
| |
| SourceString get name => element.name; |
| |
| InterfaceType _createType(Link<DartType> newTypeArguments) { |
| return new InterfaceType(element, newTypeArguments); |
| } |
| |
| /** |
| * Returns the type as an instance of class [other], if possible, null |
| * otherwise. |
| */ |
| DartType asInstanceOf(ClassElement other) { |
| if (element == other) return this; |
| for (InterfaceType supertype in element.allSupertypes) { |
| ClassElement superclass = supertype.element; |
| if (superclass == other) { |
| Link<DartType> arguments = Types.substTypes(supertype.typeArguments, |
| typeArguments, |
| element.typeVariables); |
| return new InterfaceType(superclass, arguments); |
| } |
| } |
| return null; |
| } |
| |
| DartType unalias(Compiler compiler) => this; |
| |
| /** |
| * Finds the method, field or property named [name] declared or inherited |
| * on this interface type. |
| */ |
| Member lookupMember(SourceString name) { |
| |
| Member createMember(InterfaceType receiver, InterfaceType declarer, |
| Element member) { |
| if (member.kind == ElementKind.FUNCTION || |
| member.kind == ElementKind.ABSTRACT_FIELD || |
| member.kind == ElementKind.FIELD) { |
| return new Member(receiver, declarer, member); |
| } |
| return null; |
| } |
| |
| ClassElement classElement = element; |
| InterfaceType receiver = this; |
| InterfaceType declarer = receiver; |
| Element member = classElement.lookupLocalMember(name); |
| if (member != null) { |
| return createMember(receiver, declarer, member); |
| } |
| for (DartType supertype in classElement.allSupertypes) { |
| declarer = supertype; |
| ClassElement lookupTarget = declarer.element; |
| member = lookupTarget.lookupLocalMember(name); |
| if (member != null) { |
| return createMember(receiver, declarer, member); |
| } |
| } |
| return null; |
| } |
| |
| bool operator ==(other) { |
| if (other is !InterfaceType) return false; |
| return super == other; |
| } |
| |
| InterfaceType asRaw() => super.asRaw(); |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitInterfaceType(this, argument); |
| } |
| } |
| |
| class FunctionType extends DartType { |
| final Element element; |
| final DartType returnType; |
| final Link<DartType> parameterTypes; |
| final Link<DartType> optionalParameterTypes; |
| |
| /** |
| * The names of the named parameters ordered lexicographically. |
| */ |
| final Link<SourceString> namedParameters; |
| |
| /** |
| * The types of the named parameters in the order corresponding to the |
| * [namedParameters]. |
| */ |
| final Link<DartType> namedParameterTypes; |
| final bool isMalformed; |
| |
| factory FunctionType(Element element, |
| DartType returnType, |
| Link<DartType> parameterTypes, |
| Link<DartType> optionalParameterTypes, |
| Link<SourceString> namedParameters, |
| Link<DartType> namedParameterTypes) { |
| // Compute [isMalformed] eagerly since it is faster than a lazy computation |
| // and since [isMalformed] most likely will be accessed in [Types.isSubtype] |
| // anyway. |
| bool isMalformed = returnType != null && |
| returnType.isMalformed || |
| hasMalformed(parameterTypes) || |
| hasMalformed(optionalParameterTypes) || |
| hasMalformed(namedParameterTypes); |
| return new FunctionType.internal(element, |
| returnType, |
| parameterTypes, |
| optionalParameterTypes, |
| namedParameters, |
| namedParameterTypes, |
| isMalformed); |
| } |
| |
| FunctionType.internal(Element this.element, |
| DartType this.returnType, |
| Link<DartType> this.parameterTypes, |
| Link<DartType> this.optionalParameterTypes, |
| Link<SourceString> this.namedParameters, |
| Link<DartType> this.namedParameterTypes, |
| bool this.isMalformed) { |
| assert(invariant(element, element.isDeclaration)); |
| // Assert that optional and named parameters are not used at the same time. |
| assert(optionalParameterTypes.isEmpty || namedParameterTypes.isEmpty); |
| assert(namedParameters.slowLength() == namedParameterTypes.slowLength()); |
| } |
| |
| TypeKind get kind => TypeKind.FUNCTION; |
| |
| DartType getNamedParameterType(SourceString name) { |
| Link<SourceString> namedParameter = namedParameters; |
| Link<DartType> namedParameterType = namedParameterTypes; |
| while (!namedParameter.isEmpty && !namedParameterType.isEmpty) { |
| if (namedParameter.head == name) { |
| return namedParameterType.head; |
| } |
| namedParameter = namedParameter.tail; |
| namedParameterType = namedParameterType.tail; |
| } |
| return null; |
| } |
| |
| DartType subst(Link<DartType> arguments, Link<DartType> parameters) { |
| if (parameters.isEmpty) { |
| assert(arguments.isEmpty); |
| // Return fast on empty substitutions. |
| return this; |
| } |
| var newReturnType = returnType.subst(arguments, parameters); |
| bool changed = !identical(newReturnType, returnType); |
| var newParameterTypes = |
| Types.substTypes(parameterTypes, arguments, parameters); |
| var newOptionalParameterTypes = |
| Types.substTypes(optionalParameterTypes, arguments, parameters); |
| var newNamedParameterTypes = |
| Types.substTypes(namedParameterTypes, arguments, parameters); |
| if (!changed && |
| (!identical(parameterTypes, newParameterTypes) || |
| !identical(optionalParameterTypes, newOptionalParameterTypes) || |
| !identical(namedParameterTypes, newNamedParameterTypes))) { |
| changed = true; |
| } |
| if (changed) { |
| // Create a new type only if necessary. |
| return new FunctionType(element, |
| newReturnType, |
| newParameterTypes, |
| newOptionalParameterTypes, |
| namedParameters, |
| newNamedParameterTypes); |
| } |
| return this; |
| } |
| |
| bool forEachMalformedType(bool f(MalformedType type)) { |
| if (!returnType.forEachMalformedType(f)) { |
| return false; |
| } |
| for (DartType parameterType in parameterTypes) { |
| if (!parameterType.forEachMalformedType(f)) { |
| return false; |
| } |
| } |
| for (DartType parameterType in optionalParameterTypes) { |
| if (!parameterType.forEachMalformedType(f)) { |
| return false; |
| } |
| } |
| for (DartType parameterType in namedParameterTypes) { |
| if (!parameterType.forEachMalformedType(f)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| DartType unalias(Compiler compiler) => this; |
| |
| DartType get typeVariableOccurrence { |
| TypeVariableType typeVariableType = returnType.typeVariableOccurrence; |
| if (typeVariableType != null) return typeVariableType; |
| |
| typeVariableType = _findTypeVariableOccurrence(parameterTypes); |
| if (typeVariableType != null) return typeVariableType; |
| |
| typeVariableType = _findTypeVariableOccurrence(optionalParameterTypes); |
| if (typeVariableType != null) return typeVariableType; |
| |
| return _findTypeVariableOccurrence(namedParameterTypes); |
| } |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitFunctionType(this, argument); |
| } |
| |
| void visitChildren(DartTypeVisitor visitor, var argument) { |
| returnType.accept(visitor, argument); |
| DartType.visitList(parameterTypes, visitor, argument); |
| DartType.visitList(optionalParameterTypes, visitor, argument); |
| DartType.visitList(namedParameterTypes, visitor, argument); |
| } |
| |
| String toString() { |
| StringBuffer sb = new StringBuffer(); |
| sb.write('('); |
| parameterTypes.printOn(sb, ', '); |
| bool first = parameterTypes.isEmpty; |
| if (!optionalParameterTypes.isEmpty) { |
| if (!first) { |
| sb.write(', '); |
| } |
| sb.write('['); |
| optionalParameterTypes.printOn(sb, ', '); |
| sb.write(']'); |
| first = false; |
| } |
| if (!namedParameterTypes.isEmpty) { |
| if (!first) { |
| sb.write(', '); |
| } |
| sb.write('{'); |
| Link<SourceString> namedParameter = namedParameters; |
| Link<DartType> namedParameterType = namedParameterTypes; |
| first = true; |
| while (!namedParameter.isEmpty && !namedParameterType.isEmpty) { |
| if (!first) { |
| sb.write(', '); |
| } |
| sb.write(namedParameterType.head); |
| sb.write(' '); |
| sb.write(namedParameter.head.slowToString()); |
| namedParameter = namedParameter.tail; |
| namedParameterType = namedParameterType.tail; |
| first = false; |
| } |
| sb.write('}'); |
| } |
| sb.write(') -> ${returnType}'); |
| return sb.toString(); |
| } |
| |
| SourceString get name => const SourceString('Function'); |
| |
| int computeArity() { |
| int arity = 0; |
| parameterTypes.forEach((_) { arity++; }); |
| return arity; |
| } |
| |
| int get hashCode { |
| int hash = 3 * returnType.hashCode; |
| for (DartType parameter in parameterTypes) { |
| hash = 17 * hash + 5 * parameter.hashCode; |
| } |
| for (DartType parameter in optionalParameterTypes) { |
| hash = 19 * hash + 7 * parameter.hashCode; |
| } |
| for (SourceString name in namedParameters) { |
| hash = 23 * hash + 11 * name.hashCode; |
| } |
| for (DartType parameter in namedParameterTypes) { |
| hash = 29 * hash + 13 * parameter.hashCode; |
| } |
| return hash; |
| } |
| |
| bool operator ==(other) { |
| if (other is !FunctionType) return false; |
| return returnType == other.returnType |
| && parameterTypes == other.parameterTypes |
| && optionalParameterTypes == other.optionalParameterTypes |
| && namedParameters == other.namedParameters |
| && namedParameterTypes == other.namedParameterTypes; |
| } |
| } |
| |
| class TypedefType extends GenericType { |
| final TypedefElement element; |
| |
| // TODO(johnniwinther): Assert that the number of arguments and parameters |
| // match, like for [InterfaceType]. |
| TypedefType(this.element, |
| [Link<DartType> typeArguments = const Link<DartType>()]) |
| : super(typeArguments, hasMalformed(typeArguments)); |
| |
| TypedefType _createType(Link<DartType> newTypeArguments) { |
| return new TypedefType(element, newTypeArguments); |
| } |
| |
| TypedefType.userProvidedBadType(this.element, |
| [Link<DartType> typeArguments = |
| const Link<DartType>()]) |
| : super(typeArguments, true); |
| |
| TypeKind get kind => TypeKind.TYPEDEF; |
| |
| SourceString get name => element.name; |
| |
| DartType unalias(Compiler compiler) { |
| // TODO(ahe): This should be [ensureResolved]. |
| compiler.resolveTypedef(element); |
| DartType definition = element.alias.unalias(compiler); |
| TypedefType declaration = element.computeType(compiler); |
| return definition.subst(typeArguments, declaration.typeArguments); |
| } |
| |
| bool operator ==(other) { |
| if (other is !TypedefType) return false; |
| return super == other; |
| } |
| |
| TypedefType asRaw() => super.asRaw(); |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitTypedefType(this, argument); |
| } |
| } |
| |
| /** |
| * Special type to hold the [dynamic] type. Used for correctly returning |
| * 'dynamic' on [toString]. |
| */ |
| class DynamicType extends InterfaceType { |
| DynamicType(ClassElement element) : super(element); |
| |
| SourceString get name => const SourceString('dynamic'); |
| |
| bool get isDynamic => true; |
| |
| accept(DartTypeVisitor visitor, var argument) { |
| return visitor.visitDynamicType(this, argument); |
| } |
| } |
| |
| /** |
| * Member encapsulates a member (method, field, property) with the types of the |
| * declarer and receiver in order to do substitution on the member type. |
| * |
| * Consider for instance these classes and the variable [: B<String> b :]: |
| * |
| * class A<E> { |
| * E field; |
| * } |
| * class B<F> extends A<F> {} |
| * |
| * In a [Member] for [: b.field :] the [receiver] is the type [: B<String> :] |
| * and the declarer is the type [: A<F> :], which is the supertype of [: B<F> :] |
| * from which [: field :] has been inherited. To compute the type of |
| * [: b.field :] we must first substitute [: E :] by [: F :] using the relation |
| * between [: A<E> :] and [: A<F> :], and then [: F :] by [: String :] using the |
| * relation between [: B<F> :] and [: B<String> :]. |
| */ |
| class Member { |
| final InterfaceType receiver; |
| final InterfaceType declarer; |
| final Element element; |
| DartType cachedType; |
| |
| Member(this.receiver, this.declarer, this.element) { |
| assert(invariant(element, element.isAbstractField() || |
| element.isField() || |
| element.isFunction(), |
| message: "Unsupported Member element: $element")); |
| } |
| |
| DartType computeType(Compiler compiler) { |
| if (cachedType == null) { |
| DartType type; |
| if (element.isAbstractField()) { |
| AbstractFieldElement abstractFieldElement = element; |
| if (abstractFieldElement.getter != null) { |
| FunctionType functionType = |
| abstractFieldElement.getter.computeType(compiler); |
| type = functionType.returnType; |
| } else { |
| FunctionType functionType = |
| abstractFieldElement.setter.computeType( |
| compiler); |
| type = functionType.parameterTypes.head; |
| if (type == null) { |
| type = compiler.types.dynamicType; |
| } |
| } |
| } else { |
| type = element.computeType(compiler); |
| } |
| if (!declarer.element.typeVariables.isEmpty) { |
| type = type.subst(declarer.typeArguments, |
| declarer.element.typeVariables); |
| type = type.subst(receiver.typeArguments, |
| receiver.element.typeVariables); |
| } |
| cachedType = type; |
| } |
| return cachedType; |
| } |
| |
| String toString() { |
| return '$receiver.${element.name.slowToString()}'; |
| } |
| } |
| |
| abstract class DartTypeVisitor<R, A> { |
| R visitType(DartType type, A argument); |
| |
| R visitVoidType(VoidType type, A argument) => |
| visitType(type, argument); |
| |
| R visitTypeVariableType(TypeVariableType type, A argument) => |
| visitType(type, argument); |
| |
| R visitFunctionType(FunctionType type, A argument) => |
| visitType(type, argument); |
| |
| R visitMalformedType(MalformedType type, A argument) => |
| visitType(type, argument); |
| |
| R visitStatementType(StatementType type, A argument) => |
| visitType(type, argument); |
| |
| R visitGenericType(GenericType type, A argument) => |
| visitType(type, argument); |
| |
| R visitInterfaceType(InterfaceType type, A argument) => |
| visitGenericType(type, argument); |
| |
| R visitTypedefType(TypedefType type, A argument) => |
| visitGenericType(type, argument); |
| |
| R visitDynamicType(DynamicType type, A argument) => |
| visitInterfaceType(type, argument); |
| } |
| |
| class SubtypeVisitor extends DartTypeVisitor<bool, DartType> { |
| final Compiler compiler; |
| final DynamicType dynamicType; |
| final VoidType voidType; |
| |
| SubtypeVisitor(Compiler this.compiler, |
| DynamicType this.dynamicType, |
| VoidType this.voidType); |
| |
| bool isSubtype(DartType t, DartType s) { |
| if (identical(t, s) || |
| identical(t, dynamicType) || |
| identical(s, dynamicType) || |
| t.isMalformed || |
| s.isMalformed || |
| identical(s.element, compiler.objectClass) || |
| identical(t.element, compiler.nullClass)) { |
| return true; |
| } |
| t = t.unalias(compiler); |
| s = s.unalias(compiler); |
| |
| return t.accept(this, s); |
| } |
| |
| bool isAssignable(DartType t, DartType s) { |
| return isSubtype(t, s) || isSubtype(s, t); |
| } |
| |
| bool visitType(DartType t, DartType s) { |
| throw 'internal error: unknown type kind ${t.kind}'; |
| } |
| |
| bool visitVoidType(VoidType t, DartType s) { |
| assert(s is! VoidType); |
| return false; |
| } |
| |
| bool visitInterfaceType(InterfaceType t, DartType s) { |
| |
| bool checkTypeArguments(InterfaceType instance, InterfaceType other) { |
| Link<DartType> tTypeArgs = instance.typeArguments; |
| Link<DartType> sTypeArgs = other.typeArguments; |
| while (!tTypeArgs.isEmpty) { |
| assert(!sTypeArgs.isEmpty); |
| if (!isSubtype(tTypeArgs.head, sTypeArgs.head)) { |
| return false; |
| } |
| tTypeArgs = tTypeArgs.tail; |
| sTypeArgs = sTypeArgs.tail; |
| } |
| assert(sTypeArgs.isEmpty); |
| return true; |
| } |
| |
| lookupCall(type) => type.lookupMember(Compiler.CALL_OPERATOR_NAME); |
| |
| // TODO(johnniwinther): Currently needed since literal types like int, |
| // double, bool etc. might not have been resolved yet. |
| t.element.ensureResolved(compiler); |
| |
| if (s is InterfaceType) { |
| if (s.element == compiler.functionClass && lookupCall(t) != null) { |
| return true; |
| } |
| InterfaceType instance = t.asInstanceOf(s.element); |
| return instance != null && checkTypeArguments(instance, s); |
| } else if (s is FunctionType) { |
| Member call = lookupCall(t); |
| if (call == null) return false; |
| return isSubtype(call.computeType(compiler), s); |
| } else { |
| return false; |
| } |
| } |
| |
| bool visitFunctionType(FunctionType t, DartType s) { |
| if (s is InterfaceType && identical(s.element, compiler.functionClass)) { |
| return true; |
| } |
| if (s is !FunctionType) return false; |
| FunctionType tf = t; |
| FunctionType sf = s; |
| if (!identical(sf.returnType, voidType) && |
| !isAssignable(tf.returnType, sf.returnType)) { |
| return false; |
| } |
| |
| // TODO(johnniwinther): Rewrite the function subtyping to be more readable |
| // but still as efficient. |
| |
| // For the comments we use the following abbreviations: |
| // x.p : parameterTypes on [:x:], |
| // x.o : optionalParameterTypes on [:x:], and |
| // len(xs) : length of list [:xs:]. |
| |
| Link<DartType> tps = tf.parameterTypes; |
| Link<DartType> sps = sf.parameterTypes; |
| while (!tps.isEmpty && !sps.isEmpty) { |
| if (!isAssignable(tps.head, sps.head)) return false; |
| tps = tps.tail; |
| sps = sps.tail; |
| } |
| if (!tps.isEmpty) { |
| // We must have [: len(t.p) <= len(s.p) :]. |
| return false; |
| } |
| if (!sf.namedParameters.isEmpty) { |
| if (!sps.isEmpty) { |
| // We must have [: len(t.p) == len(s.p) :]. |
| return false; |
| } |
| // Since named parameters are globally ordered we can determine the |
| // subset relation with a linear search for [:sf.namedParameters:] |
| // within [:tf.namedParameters:]. |
| Link<SourceString> tNames = tf.namedParameters; |
| Link<DartType> tTypes = tf.namedParameterTypes; |
| Link<SourceString> sNames = sf.namedParameters; |
| Link<DartType> sTypes = sf.namedParameterTypes; |
| while (!tNames.isEmpty && !sNames.isEmpty) { |
| if (sNames.head == tNames.head) { |
| if (!isAssignable(tTypes.head, sTypes.head)) return false; |
| |
| sNames = sNames.tail; |
| sTypes = sTypes.tail; |
| } |
| tNames = tNames.tail; |
| tTypes = tTypes.tail; |
| } |
| if (!sNames.isEmpty) { |
| // We didn't find all names. |
| return false; |
| } |
| } else { |
| // Check the remaining [: s.p :] against [: t.o :]. |
| tps = tf.optionalParameterTypes; |
| while (!tps.isEmpty && !sps.isEmpty) { |
| if (!isAssignable(tps.head, sps.head)) return false; |
| tps = tps.tail; |
| sps = sps.tail; |
| } |
| if (!sps.isEmpty) { |
| // We must have [: len(t.p) + len(t.o) >= len(s.p) :]. |
| return false; |
| } |
| if (!sf.optionalParameterTypes.isEmpty) { |
| // Check the remaining [: s.o :] against the remaining [: t.o :]. |
| sps = sf.optionalParameterTypes; |
| while (!tps.isEmpty && !sps.isEmpty) { |
| if (!isAssignable(tps.head, sps.head)) return false; |
| tps = tps.tail; |
| sps = sps.tail; |
| } |
| if (!sps.isEmpty) { |
| // We didn't find enough parameters: |
| // We must have [: len(t.p) + len(t.o) <= len(s.p) + len(s.o) :]. |
| return false; |
| } |
| } else { |
| if (!sps.isEmpty) { |
| // We must have [: len(t.p) + len(t.o) >= len(s.p) :]. |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| bool visitTypeVariableType(TypeVariableType t, DartType s) { |
| // Identity check is handled in [isSubtype]. |
| DartType bound = t.element.bound; |
| if (bound.element.isTypeVariable()) { |
| // The bound is potentially cyclic so we need to be extra careful. |
| Link<TypeVariableElement> seenTypeVariables = |
| const Link<TypeVariableElement>(); |
| seenTypeVariables = seenTypeVariables.prepend(t.element); |
| while (bound.element.isTypeVariable()) { |
| TypeVariableElement element = bound.element; |
| if (identical(bound.element, s.element)) { |
| // [t] extends [s]. |
| return true; |
| } |
| if (seenTypeVariables.contains(element)) { |
| // We have a cycle and have already checked all bounds in the cycle |
| // against [s] and can therefore conclude that [t] is not a subtype |
| // of [s]. |
| return false; |
| } |
| seenTypeVariables = seenTypeVariables.prepend(element); |
| bound = element.bound; |
| } |
| } |
| return isSubtype(bound, s); |
| } |
| } |
| |
| class Types { |
| final Compiler compiler; |
| // TODO(karlklose): should we have a class Void? |
| final VoidType voidType; |
| final DynamicType dynamicType; |
| final SubtypeVisitor subtypeVisitor; |
| |
| factory Types(Compiler compiler, BaseClassElementX dynamicElement) { |
| LibraryElement library = new LibraryElementX(new Script(null, null)); |
| VoidType voidType = new VoidType(new VoidElementX(library)); |
| DynamicType dynamicType = new DynamicType(dynamicElement); |
| dynamicElement.rawTypeCache = dynamicElement.thisType = dynamicType; |
| SubtypeVisitor subtypeVisitor = |
| new SubtypeVisitor(compiler, dynamicType, voidType); |
| return new Types.internal(compiler, voidType, dynamicType, subtypeVisitor); |
| } |
| |
| Types.internal(this.compiler, this.voidType, this.dynamicType, |
| this.subtypeVisitor); |
| |
| /** Returns true if t is a subtype of s */ |
| bool isSubtype(DartType t, DartType s) { |
| return subtypeVisitor.isSubtype(t, s); |
| } |
| |
| bool isAssignable(DartType r, DartType s) { |
| return subtypeVisitor.isAssignable(r, s); |
| } |
| |
| |
| /** |
| * Helper method for performing substitution of a linked list of types. |
| * |
| * If no types are changed by the substitution, the [types] is returned |
| * instead of a newly created linked list. |
| */ |
| static Link<DartType> substTypes(Link<DartType> types, |
| Link<DartType> arguments, |
| Link<DartType> parameters) { |
| bool changed = false; |
| var builder = new LinkBuilder<DartType>(); |
| Link<DartType> typeLink = types; |
| while (!typeLink.isEmpty) { |
| var argument = typeLink.head.subst(arguments, parameters); |
| if (!changed && !identical(argument, typeLink.head)) { |
| changed = true; |
| } |
| builder.addLast(argument); |
| typeLink = typeLink.tail; |
| } |
| if (changed) { |
| // Create a new link only if necessary. |
| return builder.toLink(); |
| } |
| return types; |
| } |
| |
| /** |
| * Combine error messages in a malformed type to a single message string. |
| */ |
| static String fetchReasonsFromMalformedType(DartType type) { |
| // TODO(johnniwinther): Figure out how to produce good error message in face |
| // of multiple errors, and how to ensure non-localized error messages. |
| var reasons = new List<String>(); |
| type.forEachMalformedType((MalformedType malformedType) { |
| ErroneousElement error = malformedType.element; |
| Message message = error.messageKind.message(error.messageArguments); |
| reasons.add(message.toString()); |
| return true; |
| }); |
| return reasons.join(', '); |
| } |
| |
| /** |
| * Returns the [ClassElement] which declares the type variables occurring in |
| * [type], or [:null:] if [type] does not contain type variables. |
| */ |
| static ClassElement getClassContext(DartType type) { |
| TypeVariableType typeVariable = type.typeVariableOccurrence; |
| if (typeVariable == null) return null; |
| return typeVariable.element.enclosingElement; |
| } |
| } |
