basstype

Basetype, or base type, refers to a fundamental, primitive data type that is directly supported by a programming language and serves as a building block for more complex data structures. Basetypes typically have a fixed set of values and a defined set of operations provided by the language. Common examples include booleans, integers, floating-point numbers, and characters; whether strings are treated as basetypes depends on language design, as some languages consider strings to be composite or derived types.

In type systems, basetypes are distinguished from derived or composite types such as arrays, records, objects, or types formed by type constructors. Basetypes are usually organized into broad categories (for example, numeric, boolean, or character) and interact with other types through casting or coercion rules. They support primitive operations, such as arithmetic on numbers or logical operations on booleans, that are defined by the language spec.

Implementation aspects of basetypes influence memory layout and runtime representation. Decisions about boxing and unboxing can affect performance and interoperability, especially in languages that distinguish between value types and reference types. Some languages expose a small, fixed set of basetypes, while others allow extensible type systems with user-defined primitive types.

In theoretical contexts, base types are atomic entities in a type system and are used to construct more complex types via type constructors such as functions, products, or sums. The concept helps ensure type safety by restricting operations to values of compatible types and by providing a core vocabulary for describing a language’s data.