More Type Inference in Java 8

Abstract

\({\mathsf {Java}} \) is extended in version eight by lambda expressions and functional interfaces, where functional interfaces are interfaces with one method. Functional interfaces represent the types of lambda expressions. The type inference mechanism will be extended, such that the types of the parameters of lambda expressions can be inferred. But types of complete lambda expressions will still not be inferable. In this paper we give a type inference algorithm for complete lambda expressions. This means that fields, local variables, as well as parameters and return types of lambda expressions do not have to be typed explicitly.