Methodenset

Methodenset, in English commonly called the method set, is a concept used in type theory and programming languages to denote the collection of methods that are available for values of a given type. It defines which operations can be invoked on those values and influences how dispatch, inheritance, and interface satisfaction are modeled. In German-language sources the term methodenset is used as the direct translation of method set.

Formal purposes and scope

A method set describes the callable operations associated with a type. Depending on the language, the method set may include methods defined with a receiver of the type itself or also those defined with a receiver of a related type such as a pointer. The distinction between different receiver kinds can affect which interfaces a type implements and how polymorphism and inheritance behave. The method set is thus central to understanding how values of a type can be used and how they participate in polymorphic interfaces.

Go and interface satisfaction

Go provides a prominent illustration of method sets. The method set of a value type T contains methods declared with receiver T, while the method set of the pointer type *T contains methods declared with receiver T or *T. A type implements an interface if its method set includes all methods required by that interface. This mechanism underpins interface satisfaction and allows the language to express consensus on behavior without explicit declarations.

Relation to other concepts

In object-oriented and other typed languages, the method set often reflects inherited or overridden methods, shaping how subtyping, overriding, and dynamic dispatch operate. The method set formalizes which behaviors are guaranteed to be callable on a value of a given type and how those behaviors interact with interfaces and type hierarchies.

See also: interface, subtyping, polymorphism, method dispatch, receiver (programming).