Package org.checkerframework.framework.util.typeinference8

Interface TypeArgumentInference

All Known Implementing Classes:

DefaultTypeArgumentInference

public interface TypeArgumentInference

Instances of TypeArgumentInference are used to infer the types of method type arguments when no explicit arguments are provided.

e.g. If we have a method declaration:

 <A,B> B method(A a, B b) {...}
 

And an invocation of that method:

 method("some Str", 35);
 

TypeArgumentInference will determine what the type arguments to type parameters A and B are. In Java, if T(A) = the type argument for a, in the above example T(A) == String and T(B) == Integer

For the Checker Framework we also need to infer reasonable annotations for these type arguments. For information on inferring type arguments see JLS chapter 18: https://docs.oracle.com/javase/specs/jls/se25/html/jls-18.html

Method Summary

Modifier and Type	Method	Description
default @Nullable AnnotatedTypeMirror	getLambdaParameterType(VariableElement param)	If param is an implicitly typed lambda parameter whose type an in-progress inference has already determined, returns that type.
InferenceResult	inferTypeArgs(AnnotatedTypeFactory typeFactory, ExpressionTree invocation, AnnotatedTypeMirror.AnnotatedExecutableType executableType)	Infer the type arguments for the method or constructor invocation given by invocation.

Method Details

inferTypeArgs

InferenceResult inferTypeArgs(AnnotatedTypeFactory typeFactory,
 ExpressionTree invocation,
 AnnotatedTypeMirror.AnnotatedExecutableType executableType)

Infer the type arguments for the method or constructor invocation given by invocation.

Parameters:

typeFactory - the type factory used to create executableType

invocation - a tree representing the method or constructor invocation for which we are inferring type arguments

executableType - the declaration type of the invoked method

Returns:

the result which includes the inferred type arguments or an error message if they were not inferred

getLambdaParameterType

default @Nullable AnnotatedTypeMirror getLambdaParameterType(VariableElement param)

If param is an implicitly typed lambda parameter whose type an in-progress inference has already determined, returns that type. Otherwise, returns null.

If an already completed inference, determined the type of the lambda parameter, null is returned.

Parameters:

param - an element that might be an implicitly typed lambda parameter

Returns:

the type of param as computed by an in-progress inference, or null