Package com.google.auto.common

Class MoreTypes

java.lang.Object

com.google.auto.common.MoreTypes

public final class MoreTypes
extends Object

Utilities related to TypeMirror instances.

Since:

2.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	MoreTypes.ArrayTypeVisitor
private static final class	MoreTypes.AsElementVisitor
private static class	MoreTypes.CastingTypeVisitor<T>
private static class	MoreTypes.CastingUncheckedVisitor	Visitor that tells whether a type is erased, in the sense of invalid reference #castIsUnchecked .
private static class	MoreTypes.ComparedElements
private static final class	MoreTypes.DeclaredTypeVisitor
private static final class	MoreTypes.EqualVisitor
private static final class	MoreTypes.EqualVisitorParam
private static final class	MoreTypes.ErrorTypeVisitor
private static final class	MoreTypes.ExecutableTypeVisitor
private static final class	MoreTypes.HashVisitor
private static final class	MoreTypes.IntersectionTypeVisitor
private static final class	MoreTypes.IsTypeOf
private static final class	MoreTypes.IsTypeVisitor
private static final class	MoreTypes.NoTypeVisitor
private static final class	MoreTypes.NullTypeVisitor
private static final class	MoreTypes.PrimitiveTypeVisitor
private static final class	MoreTypes.ReferencedTypes
private static final class	MoreTypes.TypeEquivalence
private static final class	MoreTypes.TypeVariableVisitor
private static final class	MoreTypes.WildcardTypeVisitor

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	HASH_MULTIPLIER
private static final int	HASH_SEED

Constructor Summary

Constructors

Modifier	Constructor	Description
private	MoreTypes()

Method Summary

Modifier and Type	Method	Description
static ArrayType	asArray(TypeMirror maybeArrayType)	Returns a ArrayType if the TypeMirror represents an array or throws an IllegalArgumentException.
static DeclaredType	asDeclared(TypeMirror maybeDeclaredType)	Returns a DeclaredType if the TypeMirror represents a declared type such as a class, interface, union/compound, or enum or throws an IllegalArgumentException.
static Element	asElement(TypeMirror typeMirror)	An alternate implementation of Types.asElement(javax.lang.model.type.TypeMirror) that does not require a Types instance with the notable difference that it will throw IllegalArgumentException instead of returning null if the TypeMirror can not be converted to an Element.
static ErrorType	asError(TypeMirror maybeErrorType)	Returns a ExecutableType if the TypeMirror represents an executable type such as may result from missing code, or bad compiles or throws an IllegalArgumentException.
static ExecutableType	asExecutable(TypeMirror maybeExecutableType)	Returns a ExecutableType if the TypeMirror represents an executable type such as a method, constructor, or initializer or throws an IllegalArgumentException.
static IntersectionType	asIntersection(TypeMirror maybeIntersectionType)	Returns an IntersectionType if the TypeMirror represents an intersection-type or throws an IllegalArgumentException.
static TypeMirror	asMemberOf(Types types, DeclaredType container, VariableElement variable)	Resolves a VariableElement parameter to a method or constructor based on the given container, or a member of a class.
static NoType	asNoType(TypeMirror maybeNoType)	Returns a NoType if the TypeMirror represents an non-type such as void, or package, etc.
static NullType	asNullType(TypeMirror maybeNullType)	Returns a NullType if the TypeMirror represents the null type or throws an IllegalArgumentException.
static PrimitiveType	asPrimitiveType(TypeMirror maybePrimitiveType)	Returns a PrimitiveType if the TypeMirror represents a primitive type or throws an IllegalArgumentException.
static TypeElement	asTypeElement(TypeMirror mirror)
static com.google.common.collect.ImmutableSet<TypeElement>	asTypeElements(Iterable<? extends TypeMirror> mirrors)
static TypeVariable	asTypeVariable(TypeMirror maybeTypeVariable)	Returns a TypeVariable if the TypeMirror represents a type variable or throws an IllegalArgumentException.
static WildcardType	asWildcard(TypeMirror maybeWildcardType)	Returns a WildcardType if the TypeMirror represents a wildcard type or throws an IllegalArgumentException.
private static TypeMirror	enclosingType(DeclaredType t)	Returns the type of the innermost enclosing instance, or null if there is none.
private static boolean	equal(TypeMirror a, TypeMirror b, Set<MoreTypes.ComparedElements> visiting)
private static boolean	equalLists(List<? extends TypeMirror> a, List<? extends TypeMirror> b, Set<MoreTypes.ComparedElements> visiting)
static com.google.common.base.Equivalence<TypeMirror>	equivalence()	Returns an Equivalence that can be used to compare types.
private static int	hash(TypeMirror mirror, Set<Element> visiting)
private static int	hashList(List<? extends TypeMirror> mirrors, Set<Element> visiting)
static boolean	isConversionFromObjectUnchecked(TypeMirror type)	Returns true if casting Object to the given type will elicit an unchecked warning from the compiler.
private static boolean	isObjectType(DeclaredType type)
static boolean	isType(TypeMirror type)	Returns true if the raw type underlying the given TypeMirror represents a type that can be referenced by a Class.
static boolean	isTypeOf(Class<?> clazz, TypeMirror type)	Returns true if the raw type underlying the given TypeMirror represents the same raw type as the given Class and throws an IllegalArgumentException if the TypeMirror does not represent a type that can be referenced by a Class
static com.google.common.base.Optional<DeclaredType>	nonObjectSuperclass(Types types, Elements elements, DeclaredType type)	Returns the superclass of type, with any type parameters bound by type, or Optional.absent() if type is an interface or Object or its superclass is Object.
static com.google.common.collect.ImmutableSet<TypeElement>	referencedTypes(TypeMirror type)	Returns the set of types that are referenced by the given TypeMirror.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

HASH_SEED

private static final int HASH_SEED

See Also:

• Constant Field Values

HASH_MULTIPLIER

private static final int HASH_MULTIPLIER

See Also:

• Constant Field Values

Constructor Details

MoreTypes

private MoreTypes()

Method Details

equivalence

public static com.google.common.base.Equivalence<TypeMirror> equivalence()

Returns an Equivalence that can be used to compare types. The standard way to compare types is Types.isSameType, but this alternative may be preferred in a number of cases:

• If you don't have an instance of Types.
• If you want a reliable hashCode() for the types, for example to construct a set of types using HashSet with Equivalence.wrap(Object).
• If you want distinct type variables to be considered equal if they have the same names and bounds.
• If you want wildcard types to compare equal if they have the same bounds. Types.isSameType never considers wildcards equal, even when comparing a type to itself.

equal

private static boolean equal(TypeMirror a,
 TypeMirror b,
 Set<MoreTypes.ComparedElements> visiting)

enclosingType

private static TypeMirror enclosingType(DeclaredType t)

Returns the type of the innermost enclosing instance, or null if there is none. This is the same as DeclaredType.getEnclosingType() except that it returns null rather than NoType for a static type. We need this because of this bug whereby the Eclipse compiler returns a value for static classes that is not NoType.

equalLists

private static boolean equalLists(List<? extends TypeMirror> a,
 List<? extends TypeMirror> b,
 Set<MoreTypes.ComparedElements> visiting)

hashList

private static int hashList(List<? extends TypeMirror> mirrors,
 Set<Element> visiting)

hash

private static int hash(TypeMirror mirror,
 Set<Element> visiting)

referencedTypes

public static com.google.common.collect.ImmutableSet<TypeElement> referencedTypes(TypeMirror type)

Returns the set of types that are referenced by the given TypeMirror.

asElement

public static Element asElement(TypeMirror typeMirror)

An alternate implementation of Types.asElement(javax.lang.model.type.TypeMirror) that does not require a Types instance with the notable difference that it will throw IllegalArgumentException instead of returning null if the TypeMirror can not be converted to an Element.

Throws:

NullPointerException - if typeMirror is null

IllegalArgumentException - if typeMirror cannot be converted to an Element

asTypeElement

public static TypeElement asTypeElement(TypeMirror mirror)

asTypeElements

public static com.google.common.collect.ImmutableSet<TypeElement> asTypeElements(Iterable<? extends TypeMirror> mirrors)

asArray

public static ArrayType asArray(TypeMirror maybeArrayType)

Returns a ArrayType if the TypeMirror represents an array or throws an IllegalArgumentException.

asDeclared

public static DeclaredType asDeclared(TypeMirror maybeDeclaredType)

Returns a DeclaredType if the TypeMirror represents a declared type such as a class, interface, union/compound, or enum or throws an IllegalArgumentException.

asError

public static ErrorType asError(TypeMirror maybeErrorType)

Returns a ExecutableType if the TypeMirror represents an executable type such as may result from missing code, or bad compiles or throws an IllegalArgumentException.

asExecutable

public static ExecutableType asExecutable(TypeMirror maybeExecutableType)

Returns a ExecutableType if the TypeMirror represents an executable type such as a method, constructor, or initializer or throws an IllegalArgumentException.

asIntersection

public static IntersectionType asIntersection(TypeMirror maybeIntersectionType)

Returns an IntersectionType if the TypeMirror represents an intersection-type or throws an IllegalArgumentException.

asNoType

public static NoType asNoType(TypeMirror maybeNoType)

Returns a NoType if the TypeMirror represents an non-type such as void, or package, etc. or throws an IllegalArgumentException.

asNullType

public static NullType asNullType(TypeMirror maybeNullType)

Returns a NullType if the TypeMirror represents the null type or throws an IllegalArgumentException.

asPrimitiveType

public static PrimitiveType asPrimitiveType(TypeMirror maybePrimitiveType)

Returns a PrimitiveType if the TypeMirror represents a primitive type or throws an IllegalArgumentException.

asTypeVariable

public static TypeVariable asTypeVariable(TypeMirror maybeTypeVariable)

Returns a TypeVariable if the TypeMirror represents a type variable or throws an IllegalArgumentException.

asWildcard

public static WildcardType asWildcard(TypeMirror maybeWildcardType)

Returns a WildcardType if the TypeMirror represents a wildcard type or throws an IllegalArgumentException.

isType

public static boolean isType(TypeMirror type)

Returns true if the raw type underlying the given TypeMirror represents a type that can be referenced by a Class. If this returns true, then isTypeOf(java.lang.Class<?>, javax.lang.model.type.TypeMirror) is guaranteed to not throw.

isTypeOf

public static boolean isTypeOf(Class<?> clazz,
 TypeMirror type)

Returns true if the raw type underlying the given TypeMirror represents the same raw type as the given Class and throws an IllegalArgumentException if the TypeMirror does not represent a type that can be referenced by a Class

nonObjectSuperclass

public static com.google.common.base.Optional<DeclaredType> nonObjectSuperclass(Types types,
 Elements elements,
 DeclaredType type)

Returns the superclass of type, with any type parameters bound by type, or Optional.absent() if type is an interface or Object or its superclass is Object.

isObjectType

private static boolean isObjectType(DeclaredType type)

asMemberOf

public static TypeMirror asMemberOf(Types types,
 DeclaredType container,
 VariableElement variable)

Resolves a VariableElement parameter to a method or constructor based on the given container, or a member of a class. For parameters to a method or constructor, the variable's enclosing element must be a supertype of the container type. For example, given a container of type Set<String>, and a variable corresponding to the E e parameter in the Set.add(E e) method, this will return a TypeMirror for String.

isConversionFromObjectUnchecked

public static boolean isConversionFromObjectUnchecked(TypeMirror type)

Returns true if casting Object to the given type will elicit an unchecked warning from the compiler. Only type variables and parameterized types such as List<String> produce such warnings. There will be no warning if the type's only type parameters are simple wildcards, as in Map<?, ?>.