randoop.reflection

Class TypeInstantiator

java.lang.Object

randoop.reflection.TypeInstantiator

public class TypeInstantiator
extends java.lang.Object

Instantiates type parameters from a set of input types.

Field Summary

Fields

Modifier and Type	Field and Description
private static boolean	debug Whether to log information about instantiation.
private java.util.Set<Type>	inputTypes The set of input types for this model.

Constructor Summary

Constructors

Constructor and Description
TypeInstantiator(java.util.Set<Type> inputTypes) Creates a TypeInstantiator object using the given types to construct instantiating substitutions.

Method Summary

Modifier and Type	Method and Description
private java.util.List<Substitution>	allExtendingSubstitutions(java.util.List<TypeVariable> typeParameters, Substitution substitution) Returns all substitutions that extend a substitution for the given type parameters.
private java.util.List<Substitution>	allSubstitutions(java.util.List<TypeVariable> parameters, Substitution initialSubstitution, BoundsCheck boundsCheck) Adds instantiating substitutions for the given parameters to the list if satisfies the given type check predicate.
private java.util.List<java.util.List<ReferenceType>>	candidateTypes(java.util.List<TypeVariable> parameters) Constructs the list of lists of candidate types for the given type parameters.
private java.util.List<ReferenceType>	candidateTypes(TypeVariable argument) Returns all input types that potentially satisfy the bounds on the argument.
private ParameterBound	getLowerBound(TypeVariable argument) Gets the lower bound of the given argument to be tested in candidateTypes(TypeVariable).
private ParameterBound	getUpperBound(TypeVariable argument) Gets the upper bound of the given argument to test in candidateTypes(TypeVariable).
@Nullable TypedClassOperation	instantiate(TypedClassOperation operation) Instantiate the given operation by choosing type arguments for its type parameters.
private @Nullable Substitution	instantiateClass(ClassOrInterfaceType type) Chooses an instantiating substitution for the given class.
private TypedClassOperation	instantiateOperationTypes(TypedClassOperation operation) Selects an instantiation of the generic types of an operation, and returns a new operation with the types instantiated.
private Substitution	instantiateSortedSetType(TypedClassOperation operation) Returns a substitution that instantiates the SortedSet type of the given constructor.
private Substitution	selectSubstitution(ClassOrInterfaceType type) Selects an existing type that instantiates the given generic declaring type and returns the instantiating substitution.
private Substitution	selectSubstitution(ClassOrInterfaceType type, ClassOrInterfaceType patternType) Returns a substitution that instantiates both type and patternType to an existing type.
private Substitution	selectSubstitution(java.util.List<TypeVariable> typeParameters) Selects an instantiating substitution for the given list of type variables.
private Substitution	selectSubstitution(java.util.List<TypeVariable> typeParameters, Substitution substitution) Extends the given substitution by instantiations for the given list of type variables.
private Substitution	selectSubstitutionForSortedSet(GenericClassType searchType, TypeVariable typeParameter) Select a substitution for the type parameter of SortedSet.
private Substitution	selectSubstitutionIndependently(java.util.List<TypeVariable> parameters, Substitution substitution) Selects types independently for a list of type parameters, and extends the given substitution by the substitution of the selected types for the parameters.

Methods inherited from class java.lang.Object

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

Field Detail

debug

private static final boolean debug

Whether to log information about instantiation.

See Also:

Constant Field Values

inputTypes

private final java.util.Set<Type> inputTypes

The set of input types for this model. The input types need to be closed on supertypes: if a type is in the input types, then so are all of its supertypes.

Constructor Detail

TypeInstantiator

public TypeInstantiator(java.util.Set<Type> inputTypes)

Creates a TypeInstantiator object using the given types to construct instantiating substitutions.

Parameters:

inputTypes - the ground types for instantiations

Method Detail

instantiate

public @Nullable TypedClassOperation instantiate(TypedClassOperation operation)

Instantiate the given operation by choosing type arguments for its type parameters.

Parameters:

operation - the generic operation to instantiate

Returns:

an instantiated version of the operation, or null

instantiateSortedSetType

private Substitution instantiateSortedSetType(TypedClassOperation operation)

Returns a substitution that instantiates the SortedSet type of the given constructor. A SortedSet may be built so that the element type E is ordered either explicitly with a Comparator<E>, or the element type satisfies E implements Comparable<E>.

Parameters:

operation - a constructor to be instantiated, for a class that implements SortedSet

Returns:

the substitution to instantiate the element type of the SortedSet type

selectSubstitutionForSortedSet

private Substitution selectSubstitutionForSortedSet(GenericClassType searchType,
                                                    TypeVariable typeParameter)

Select a substitution for the type parameter of SortedSet.

Parameters:

searchType - one of Comparator, Comparable, or SortedSet

typeParameter - the type parameter to create an instantiation for

Returns:

a substitution for the type parameter of SortedSet

instantiateClass

private @Nullable Substitution instantiateClass(ClassOrInterfaceType type)

Chooses an instantiating substitution for the given class. Performs a coin flip to determine whether to use a previous instantiation, or to create a new one. Verifies that all of the type parameters of the type are instantiated, and logs failure if not.

Parameters:

type - the type to be instantiated

Returns:

a substitution instantiating the given type; null if none is found

selectSubstitution

private Substitution selectSubstitution(ClassOrInterfaceType type,
                                        ClassOrInterfaceType patternType)

Returns a substitution that instantiates both type and patternType to an existing type. The pattern type makes it possible to select matches for partial instantiations of a generic type.

Parameters:

type - the generic type for which an instantiation is to be found

patternType - an instantiation of type; only further instantiations of it are considered

Returns:

a substitution instantiating type's type parameters to existing types; null if no such substitution exists

selectSubstitution

private Substitution selectSubstitution(ClassOrInterfaceType type)

Selects an existing type that instantiates the given generic declaring type and returns the instantiating substitution.

Parameters:

type - the generic type for which an instantiation is to be found

Returns:

a substitution instantiating the given type as an existing type; null if no such type

instantiateOperationTypes

private TypedClassOperation instantiateOperationTypes(TypedClassOperation operation)

Selects an instantiation of the generic types of an operation, and returns a new operation with the types instantiated.

Parameters:

operation - the operation

Returns:

the operation with generic types instantiated

selectSubstitution

private Substitution selectSubstitution(java.util.List<TypeVariable> typeParameters)

Selects an instantiating substitution for the given list of type variables.

Parameters:

typeParameters - the type variables to be instantiated

Returns:

a substitution instantiating the type variables; null if some type variable has no instantiating types

See Also:

selectSubstitution(List, Substitution)

selectSubstitution

private Substitution selectSubstitution(java.util.List<TypeVariable> typeParameters,
                                        Substitution substitution)

Extends the given substitution by instantiations for the given list of type variables.

Parameters:

typeParameters - the type variables to be instantiated

substitution - the substitution to extend

Returns:

the substitution extended by instantiating type variables; null if any of the variables has no instantiating types

allExtendingSubstitutions

private java.util.List<Substitution> allExtendingSubstitutions(java.util.List<TypeVariable> typeParameters,
                                                               Substitution substitution)

Returns all substitutions that extend a substitution for the given type parameters.

Parameters:

typeParameters - the type parameters to be instantiated

substitution - the substitution to be extended

Returns:

the list of possible substitutions, empty if none is found

selectSubstitutionIndependently

private Substitution selectSubstitutionIndependently(java.util.List<TypeVariable> parameters,
                                                     Substitution substitution)

Selects types independently for a list of type parameters, and extends the given substitution by the substitution of the selected types for the parameters.

IMPORTANT: Should only be used for parameters that have non-generic bounds.

Parameters:

parameters - a list of independent type parameters

substitution - the substitution to extend

Returns:

the substitution extended by mapping given parameters to selected types; null, if there are no candidate types for some parameter

allSubstitutions

private java.util.List<Substitution> allSubstitutions(java.util.List<TypeVariable> parameters,
                                                      Substitution initialSubstitution,
                                                      BoundsCheck boundsCheck)

Adds instantiating substitutions for the given parameters to the list if satisfies the given type check predicate. Each constructed substitution extends the given initial substitution. Assumes that the parameters are or are refinements of the set of parameters check by the type check predicate.

Parameters:

parameters - the list of parameters to instantiate

initialSubstitution - the substitution to be extended by new substitutions

boundsCheck - the predicate to type check a substitution

Returns:

the list of instantiating substitutions; may be empty. The list is fresh and clients may side-effect it.

candidateTypes

private java.util.List<java.util.List<ReferenceType>> candidateTypes(java.util.List<TypeVariable> parameters)

Constructs the list of lists of candidate types for the given type parameters. Each sub list is the list of candidates for the corresponding parameter in parameters, as determined by candidateTypes(TypeVariable).

Parameters:

parameters - the list of type parameters

Returns:

the list of candidate lists for the parameters; returns the empty list if any parameter has no candidates

candidateTypes

private java.util.List<ReferenceType> candidateTypes(TypeVariable argument)

Returns all input types that potentially satisfy the bounds on the argument. If a bound has another type parameter, then the default bound is tested. The caller allSubstitutions(java.util.List<randoop.types.TypeVariable>, randoop.types.Substitution, randoop.types.BoundsCheck) will ensure that the final substitution is consistent.

Parameters:

argument - the type argument

Returns:

the list of candidate instantiations of the type argument

getUpperBound

private ParameterBound getUpperBound(TypeVariable argument)

Gets the upper bound of the given argument to test in candidateTypes(TypeVariable). If the bound contains a type parameter other than the given argument, then returns Object as the bound.

Parameters:

argument - the type argument

Returns:

the upperbound of the argument if no other type parameter is needed, the Object bound otherwise

getLowerBound

private ParameterBound getLowerBound(TypeVariable argument)

Gets the lower bound of the given argument to be tested in candidateTypes(TypeVariable). If the bound has a type parameter other than the given argument, then returns JavaTypes.NULL_TYPE as the bound.

Parameters:

argument - the type argument

Returns:

the lower bound of the argument if no other type parameter is needed, the JavaTypes.NULL_TYPE otherwise