uk.co.strangeskies.reflection

Class TypeSubstitution

java.lang.Object

uk.co.strangeskies.reflection.TypeSubstitution

public class TypeSubstitution
extends java.lang.Object

A TypeSubstitution object is a function mapping Type to Type, which recursively visits each type mentioned by a given type and applies a substitution to those it encounters which match a given condition.

Constructor Summary

Constructors

Constructor and Description
TypeSubstitution() Create a new TypeSubstitution with no initial substitution rules.
TypeSubstitution(java.util.function.Function<? super java.lang.reflect.Type,? extends java.lang.reflect.Type> mapping) Create a new TypeSubstitution to apply the given mapping function.
TypeSubstitution(java.util.Map<? extends java.lang.reflect.Type,? extends java.lang.reflect.Type> mapping) Create a new TypeSubstitution to apply the given mapping.

Method Summary

Modifier and Type	Method and Description
java.lang.reflect.Type	resolve(java.lang.reflect.Type type) Resolve the result of this substitution as applied to the given type.
protected java.lang.reflect.Type	resolve(java.lang.reflect.Type type, IdentityProperty<java.lang.Boolean> changed)
TypeSubstitution	where(java.util.function.Predicate<? super java.lang.reflect.Type> from, java.util.function.Function<? super java.lang.reflect.Type,? extends java.lang.reflect.Type> to) Create a new TypeSubstitution by adding a specific single substitution rule to the receiver of the invocation.
TypeSubstitution	where(java.lang.reflect.Type from, java.lang.reflect.Type to) Create a new TypeSubstitution by adding a specific single substitution rule to the receiver of the invocation.
TypeSubstitution	withIsomorphism(Isomorphism isomorphism) Create a new TypeSubstitution which is the same as the receiver with the additional behavior that it maps types according to the given Isomorphism.
TypeSubstitution	withTypeVariables() Create a new TypeSubstitution which is the same as the receiver with the additional behavior that type variables are also included for bounds substitution.

Methods inherited from class java.lang.Object

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

Constructor Detail

TypeSubstitution

public TypeSubstitution()

Create a new TypeSubstitution with no initial substitution rules.

TypeSubstitution

public TypeSubstitution(java.util.function.Function<? super java.lang.reflect.Type,? extends java.lang.reflect.Type> mapping)

Create a new TypeSubstitution to apply the given mapping function. Typically we do something like create an instance from a Map of Type instances to other Type instances, then pass the method reference of Map.get(Object) for that map to this constructor. For this specific example use case though, TypeSubstitution(Map) would perform slightly better.

Parameters:

mapping - A mapping function for transforming encountered types to their substitution types.

TypeSubstitution

public TypeSubstitution(java.util.Map<? extends java.lang.reflect.Type,? extends java.lang.reflect.Type> mapping)

Create a new TypeSubstitution to apply the given mapping. This is more efficient than the more general TypeSubstitution(Function) constructor, as it can skip type traversal for empty maps.

Parameters:

mapping - A mapping function for transforming encountered types to their substitution types.

Method Detail

where

public TypeSubstitution where(java.lang.reflect.Type from,
                              java.lang.reflect.Type to)

Create a new TypeSubstitution by adding a specific single substitution rule to the receiver of the invocation. The new rule will be checked and applied before any existing rules. The receiving TypeSubstitution of invocation of this method will remain unchanged.

Parameters:

from - The type to match in application of this rule.

to - The type to substitute for types which match the rule.

Returns:

A new TypeSubstitution object with the rule added.

where

public TypeSubstitution where(java.util.function.Predicate<? super java.lang.reflect.Type> from,
                              java.util.function.Function<? super java.lang.reflect.Type,? extends java.lang.reflect.Type> to)

Create a new TypeSubstitution by adding a specific single substitution rule to the receiver of the invocation. The new rule will be checked and applied before any existing rules. The receiving TypeSubstitution of invocation of this method will remain unchanged.

Parameters:

from - The type matching condition of the new rule.

to - The substitution transformation to apply to types matching the given condition.

Returns:

A new TypeSubstitution object with the rule added.

withTypeVariables

public TypeSubstitution withTypeVariables()

Create a new TypeSubstitution which is the same as the receiver with the additional behavior that type variables are also included for bounds substitution. Normally it makes sense to exclude type variable bounds for substitution, as their type is immutable and baked into their defining class definition, but sometimes we may still want this behavior.

Returns:

a new TypeSubstitution object with the rule added

withIsomorphism

public TypeSubstitution withIsomorphism(Isomorphism isomorphism)

Create a new TypeSubstitution which is the same as the receiver with the additional behavior that it maps types according to the given Isomorphism.

Parameters:

isomorphism - an isomorphism

Returns:

a new TypeSubstitution object over the given isomorphism

resolve

public java.lang.reflect.Type resolve(java.lang.reflect.Type type)

Resolve the result of this substitution as applied to the given type.

Parameters:

type - The type for which we want to make a substitution.

Returns:

The result of application of this substitution. The result is not guaranteed to be well formed with respect to bounds.

resolve

protected java.lang.reflect.Type resolve(java.lang.reflect.Type type,
                                         IdentityProperty<java.lang.Boolean> changed)