TypeCan

TypeCan is a term used in discussions of type theory and programming languages to denote a mechanism for representing and manipulating canonical forms of types and, in some contexts, type-level values. The name is not tied to a single standard and can refer to theoretical frameworks as well as concrete implementations such as libraries or language features that enforce canonicity.

At its core, TypeCan emphasizes canonicity—the idea that every type or type-level expression has a unique, representative form. This is often paired with normalization, a process that reduces complex or equivalent types to their canonical form. Together, these ideas aim to support decidable type equality, simplified generic programming, and reliable interoperability between differently expressed types.

Practical TypeCan offerings range from compiler plugins and language extensions to standalone libraries. They typically provide facilities to convert a given type to its canonical form, compare canonical representations efficiently, and derive constraints or proofs based on type equality. In some designs, type-level computations (such as type families or generics) feed into the canonicalization pipeline to maintain consistency across modules or data serializations.

TypeCan is not a universally standardized term. In different ecosystems it may refer to varying notions of canonical type representations, or to project-specific libraries that implement similar ideas. The article notes that the term is used more frequently in niche communities and theoretical discussions than in mainstream language documentation.