Hello Rick I suspect that in the context of Oleg's piece, a "distinguished type" is merely a type that can be distinguished rather than a common concept like say a "dynamic type" or a "sum type". As he mentions further some types can have only one value such as Haskell's unit type - (). I can't find a definition for "distinguished type" in any of the programming books I've checked: various Haskell ones, Pierce's TAPL, and and various Scheme ones - Friedman, Wand and Haynes's EoPL, Lisp in Small Pieces and Springer and Friedman's Scheme and the Art of Programming; nor from a few searches on the web. Best wishes Stephen On 13 February 2010 20:29, Rick Murphy <rick@rickmurphy.org> wrote:
I understand from [1] that a distinguised type is defined as a type with only one non-bottom value and that value is in fact identical to the name of the type. [1] provides the unit type () as an example of a Haskell distinguished type.