data types Many of the data types which in other languages would have to be expressed as abstract data types can be represented in Miranda as algebraic data types with associated laws. Nevertheless there is still a need for abstract data types, as may be seen from the following example (which is based on a use of abstract data types in the LCF system [Gordon et al 79]).

In several steps the Java type system is extended by features, which we know from functional programming languages. In Java 5.0 [GJSB05] generic types as well as a limited form of existential types (bounded wildcards) are introduced. In Java 8 the language will be expanded by lambda expressions, functional interfaces as target types, method and constructor references and default methods. In an ...