Numerical tower
From Free net encyclopedia
In computing, a numerical tower is the set of number types (data types that represent numbers) in a given programming language.
Each type in the tower conceptually ‘sits on’ a more fundamental type, so an integer is a rational number and a number, but the inverse is not necessarily true, i. e. not every number is an integer.
Typically a language will support a modified version of this numerical tower; Kawa Scheme, for example, extends this basic numerical tower with a Quantity type that is even more generic than Number. Another popular variant is having both exact and inexact versions of the tower or parts of it. Some languages and language implementations do not support a full numerical tower or support it only in a limited way.