Chapter 3. Types
The types of the M lansguage are divided into two main categories: intrinsic types and derived types. An intrinsic type is a type that cannot be defined using M language constructs but rather is defined entirely in the M Language Specification. An intrinsic type (for example,
Collection) may name a supertype as part of its specification. Values are an instance of exactly one intrinsic type, and conform to the specification of that one intrinsic type and all of its supertypes.
A derived type (for example,
Cars) is a type whose definition is constructed in M source text using the type constructors that are provided in the language. A derived type is defined as a constraint over another type, which ...