org.checkerframework.framework.util

Class TypeArgumentMapper

java.lang.Object

org.checkerframework.framework.util.TypeArgumentMapper

public class TypeArgumentMapper
extends Object

Records any mapping between the type parameters of a subtype to the corresponding type parameters of a supertype. For example, suppose we have the following classes:

 class Map<M1,M2>
 class HashMap<H1, H2> extends Map<H1,H2>
 

And we pass HashMap and Map to mapTypeArguments, the result would be:

 Map(H1 ⇒ M1, H2 ⇒ M2)
 

Note, a single type argument in the subtype can map to multiple type parameters in the supertype. e.g.,

 class OneTypeMap<O1> extends Map<O1,O1>
 

would have the result:

 Map(O1 ⇒ [M1,M2])
 

This utility only maps between corresponding type parameters, so the following class:

 class StringMap extends Map<String,String>
 

would have an empty map as a result:

 Map() // there are no type argument relationships between the two types
 

Constructor Summary

Constructors

Constructor and Description
TypeArgumentMapper()

Method Summary

Modifier and Type	Method and Description
static Set<Pair<Integer,Integer>>	mapTypeArgumentIndices(TypeElement subtype, TypeElement supertype, Types types) Returns a mapping from subtype's type parameter indices to the indices of corresponding type parameters in supertype.
static Map<TypeParameterElement,Set<TypeParameterElement>>	mapTypeArguments(TypeElement subtype, TypeElement supertype, Types types) Returns a mapping from the type parameters of subtype to a list of the type parameters in supertype that must be the same type as subtype.

Methods inherited from class java.lang.Object

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

Constructor Detail

TypeArgumentMapper

public TypeArgumentMapper()

Method Detail

mapTypeArgumentIndices

public static Set<Pair<Integer,Integer>> mapTypeArgumentIndices(TypeElement subtype,
                                                                TypeElement supertype,
                                                                Types types)

Returns a mapping from subtype's type parameter indices to the indices of corresponding type parameters in supertype.

mapTypeArguments

public static Map<TypeParameterElement,Set<TypeParameterElement>> mapTypeArguments(TypeElement subtype,
                                                                                   TypeElement supertype,
                                                                                   Types types)

Returns a mapping from the type parameters of subtype to a list of the type parameters in supertype that must be the same type as subtype.

e.g.,

 class A<A1,A2,A3>
 class B<B1,B2,B3,B4> extends A<B1,B1,B3> {}
 

results in a Map(B1 ⇒ [A1,A2], B2 ⇒ [], B3 ⇒ [A3], B4 ⇒ [])

Returns:

a mapping from the type parameters of subtype to the supertype type parameter's that to which they are a type argument