Typar

Typar is a term used in different contexts, most commonly in programming and in construction.

In programming, typar is shorthand for a type parameter. It denotes a placeholder type used in generic or parametric code. In the ML family of languages and in the F# ecosystem, Typar appears as the internal representation of a type parameter within the compiler and type system. The concept is analogous to type variables such as T or A in other languages and is essential for defining generic data structures and functions that operate over multiple types. Typar usage emphasizes abstracted types and the constraints that may be placed on them.

In construction, Typar is a brand name for a breathable weather barrier, commonly used as house wrap during building projects. Typar products are installed on the exterior side of wall assemblies to reduce air leakage while allowing water vapor to escape, helping protect structural components from moisture and contributing to energy efficiency. Product lines and formulations vary, but the core purpose is to provide a barrier that sheds liquid water while remaining permeable to vapor.

Because typar can refer to more than one concept, its meaning is highly context-dependent. In software development discussions, it almost always relates to type parameters in generic programming, whereas in building and construction contexts, it refers to a brand of house wrap.