uk.co.strangeskies.reflection

Class InferenceVariable

java.lang.Object

uk.co.strangeskies.reflection.InferenceVariable

All Implemented Interfaces:

java.lang.reflect.Type

public class InferenceVariable
extends java.lang.Object
implements java.lang.reflect.Type

An inference variable can be thought of as a placeholder for an instantiation of a TypeVariable of which we do not yet know the exact type. An InferenceVariable alone has no bounds or type information attached to it. Instead, typically, they are contained within the context of one or more BoundSets, which will track bounds on a set of inference variables such they their exact type can ultimately be inferred.

Constructor Summary

Constructors

Constructor and Description
InferenceVariable() Create a new inference variable with a basic generated name, which is contained within this bound set.
InferenceVariable(java.lang.String name) Create a new inference variable with the given name.

Method Summary

Modifier and Type	Method and Description
static java.lang.reflect.ParameterizedType	captureConversion(java.lang.reflect.ParameterizedType type, BoundSet bounds) Create fresh InferenceVariables for each parameter of the given type - and each non-statically enclosing type thereof - which is a WildcardType.
static java.util.stream.Stream<InferenceVariable>	getMentionedBy(java.lang.reflect.Type type) Find all inference variables mentioned by a type, whether in any bounds, parameters, array types, etc.
java.lang.String	getName()
long	getNumber()
static boolean	isProperType(java.lang.reflect.Type type) Determine whether a given type is proper.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.reflect.Type

getTypeName

Constructor Detail

InferenceVariable

public InferenceVariable()

Create a new inference variable with a basic generated name, which is contained within this bound set.

InferenceVariable

public InferenceVariable(java.lang.String name)

Create a new inference variable with the given name.

Parameters:

name - A name to assign to a new inference variable.

Method Detail

getName

public java.lang.String getName()

Returns:

The given name of the inference variable.

getNumber

public long getNumber()

Returns:

The internally assigned number which uniquely distinguishes the inference variable from others with the same name.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

captureConversion

public static java.lang.reflect.ParameterizedType captureConversion(java.lang.reflect.ParameterizedType type,
                                                                    BoundSet bounds)

Create fresh InferenceVariables for each parameter of the given type - and each non-statically enclosing type thereof - which is a WildcardType. New bounds based on the bounds of those wildcards, and the bounds of the TypeVariables they substitute, will be incorporated into the given BoundSet, along with a CaptureConversion bound representing this capture conversion. The process of capture conversion is described in more detail in the Java 8 language specification.

Parameters:

type - A parameterised type whose wildcard type arguments, if present, we wish to capture as inference variables.

bounds - The bound set we wish to create any fresh inference variables within, and incorporate any newly implied bounds into.

Returns:

A new parameterized type derived from the given parameterized type, with any fresh InferenceVariables substituted for the type arguments.

getMentionedBy

public static java.util.stream.Stream<InferenceVariable> getMentionedBy(java.lang.reflect.Type type)

Find all inference variables mentioned by a type, whether in any bounds, parameters, array types, etc. recursively.

Parameters:

type - The type in which to find inference variable mentions.

Returns:

The inference variables mentioned by the given type.

isProperType

public static boolean isProperType(java.lang.reflect.Type type)

Determine whether a given type is proper.

Parameters:

type - The type for which to determine properness.

Returns:

True if the given type is proper, false otherwise.