randoop.types

Class ReferenceType

java.lang.Object

randoop.types.Type

randoop.types.ReferenceType

All Implemented Interfaces:

java.lang.Comparable<Type>

Direct Known Subclasses:

ArrayType, ClassOrInterfaceType, NullReferenceType, ParameterType

public abstract class ReferenceType
extends Type

Represents a reference type defined in JLS Section 4.3

   ReferenceType:
     ClassOrInterfaceType
     TypeVariable
     ArrayType
 

This abstract type is used to mirror the grammar in the JLS.

Constructor Summary

Constructors

Constructor and Description
ReferenceType()

Method Summary

Modifier and Type	Method and Description
ReferenceType	applyCaptureConversion() Applies a capture conversion to this type.
static ReferenceType	forClass(java.lang.Class<?> classType) Returns a ReferenceType object for the given Class object.
static ReferenceType	forType(java.lang.reflect.Type type) Creates a ReferenceType for the given java.lang.reflect.Type.
@Nullable Substitution	getInstantiatingSubstitution(ReferenceType goalType) Computes a substitution that can be applied to the type variables of the generic goal type to instantiate operations of this type, possibly inherited from from the goal type.
static Substitution	getInstantiatingSubstitutionforTypeVariable(ReferenceType instantiatedType, ReferenceType goalType) Static helper method that does the work of getInstantiatingSubstitution, if goalType is a type variable.
java.util.List<TypeVariable>	getTypeParameters() Returns the list of type parameters for this type.
boolean	isAssignableFrom(Type sourceType) Indicates whether there is an assignment conversion from a source Type to this type.
boolean	isCaptureVariable() Indicates whether this type is a capture type variable as constructed by InstantiatedType.applyCaptureConversion().
boolean	isInstantiationOf(ReferenceType otherType) Indicates whether this type is an instantiation of a more general type.
boolean	isReferenceType() Indicates whether this is a reference type.
boolean	isSubtypeOf(Type otherType) Test whether this type is a subtype of the given type according to transitive closure of definition of the direct supertype relation in section 4.10 of JLS for Java SE 8.
abstract ReferenceType	substitute(Substitution substitution) Applies a substitution to a ReferenceType.

Methods inherited from class randoop.types.Type

compareTo, forFullyQualifiedName, forName, forValue, getBinaryName, getCanonicalName, getFqName, getRawtype, getRuntimeClass, getSimpleName, getTypeforFullyQualifiedName, getUnqualifiedBinaryName, hasCaptureVariable, hasWildcard, isArray, isAssignableFromTypeOf, isBoxedPrimitive, isClass, isClassOrInterfaceType, isEnum, isGeneric, isGeneric, isInterface, isNonreceiverType, isObject, isParameterized, isPrimitive, isRawtype, isString, isVariable, isVoid, runtimeClassIs, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ReferenceType

public ReferenceType()

Method Detail

forClass

public static ReferenceType forClass(java.lang.Class<?> classType)

Returns a ReferenceType object for the given Class object. Creates arrays, classes, and interfaces. For arrays, calls ArrayType.forClass(Class). For other (class/interface) types, calls ClassOrInterfaceType.forClass(Class).

Parameters:

classType - the Class object representing the type

Returns:

the ReferenceType object for the given type

forType

public static ReferenceType forType(java.lang.reflect.Type type)

Creates a ReferenceType for the given java.lang.reflect.Type. Specifically, creates

• an ArrayType if the reference is GenericArrayType or is a Class object representing an array.
• a TypeVariable) if the reference is java.lang.reflect.TypeVariable.
• a ClassOrInterfaceType if the reference is none of those.

Parameters:

type - the type reference

Returns:

the ReferenceType for the given Type

substitute

public abstract ReferenceType substitute(Substitution substitution)

Applies a substitution to a ReferenceType. If the type is parameterized then replaces type variables that occur, otherwise returns this type.

This abstract method forces typing of substitutions applied to ReferenceType objects without an explicit cast.

Overrides:

substitute in class Type

Parameters:

substitution - the type substitution

Returns:

the type created by applying the substitution to this type

applyCaptureConversion

public ReferenceType applyCaptureConversion()

Description copied from class: Type

Applies a capture conversion to this type.

Overrides:

applyCaptureConversion in class Type

Returns:

a copy of this type with wildcards replaced by type conversion

getTypeParameters

public java.util.List<TypeVariable> getTypeParameters()

Returns the list of type parameters for this type. Reference types that may have type parameters include ArrayType (such as E[]), and subclasses of ParameterizedType.

Returns:

the type parameters for this type

isAssignableFrom

public boolean isAssignableFrom(Type sourceType)

Indicates whether there is an assignment conversion from a source Type to this type. (In other words, a value of the source type can be assigned to an l-value of this type.) Returns true if this is a legal assignment conversion: Variablethis = Expressionsourcetype.

Based on the definition of assignment context in section 5.2 of the Java Language Specification, a value of one type is assignable to a variable of another type if the first type can be converted to the second by

• an identity conversion (section 5.1.1),
• a widening primitive conversion (section 5.1.2),
• a widening reference conversion (section 5.1.5),
• a boxing conversion (5.1.7), or
• an unboxing conversion (section 5.1.8) possibly followed by a widening conversion.

And, if after all those conversions, the type is a raw type, an unchecked conversion may occur.

For assignment to ReferenceType, checks for widening reference conversion when the source type is also a reference type. See section JLS 5.1.5 for details.

Overrides:

isAssignableFrom in class Type

Parameters:

sourceType - the type to test for assignability

Returns:

true if this type can be assigned from the source type, and false otherwise

isCaptureVariable

public boolean isCaptureVariable()

Indicates whether this type is a capture type variable as constructed by InstantiatedType.applyCaptureConversion(). A capture type variable can only occur as a type argument in an InstantiatedType constructed by InstantiatedType.applyCaptureConversion().

Returns:

true if this type is a capture type variable, false otherwise

isInstantiationOf

public boolean isInstantiationOf(ReferenceType otherType)

Indicates whether this type is an instantiation of a more general type.

For a general ReferenceType, this is only true if the other type is the same, or the other type is a type variable for which this type satisfies the bounds. Other cases are handled by the overriding implementations ClassOrInterfaceType.isInstantiationOf(ReferenceType), InstantiatedType.isInstantiationOf(ReferenceType), and TypeVariable.isInstantiationOf(ReferenceType).

Parameters:

otherType - the general reference type

Returns:

true if this type instantiates the other reference type, false otherwise

getInstantiatingSubstitution

public @Nullable Substitution getInstantiatingSubstitution(ReferenceType goalType)

Computes a substitution that can be applied to the type variables of the generic goal type to instantiate operations of this type, possibly inherited from from the goal type. The substitution will unify this type or a supertype of this type with the given goal type.

If there is no unifying substitution, returns null.

Parameters:

goalType - the generic type for which a substitution is needed

Returns:

a substitution unifying this type or a supertype of this type with the goal type

getInstantiatingSubstitutionforTypeVariable

public static Substitution getInstantiatingSubstitutionforTypeVariable(ReferenceType instantiatedType,
                                                                       ReferenceType goalType)

Static helper method that does the work of getInstantiatingSubstitution, if goalType is a type variable.

Parameters:

instantiatedType - the first type

goalType - the generic type for which a substitution is needed

Returns:

a substitution unifying this first type or a supertype of the first type with the goal type

isReferenceType

public boolean isReferenceType()

Description copied from class: Type

Indicates whether this is a reference type. Note: implementing classes should ensure that this is equivalent to !(this.isPrimitive())

Overrides:

isReferenceType in class Type

Returns:

true if this type is a reference type, and false otherwise

isSubtypeOf

public boolean isSubtypeOf(Type otherType)

Test whether this type is a subtype of the given type according to transitive closure of definition of the direct supertype relation in section 4.10 of JLS for Java SE 8.

For ReferenceType, returns true if otherType is Object.

Overrides:

isSubtypeOf in class Type

Parameters:

otherType - the possible supertype

Returns:

true if this type is a subtype of the given type, false otherwise