On Mon, Jan 05, 2015 at 05:58:31PM -0500, Sean Kanaley wrote: > I see "void" as a tangible value specifying no information, whereas > "undefined" is literally no information. So void is more like an empty > universe and undefined is no universe at all.
Algol 68 had a void value, called 'empty' in the defining report, but it didn't need a name in the language itself, because there were too many easy ways of geerating it. I always considered void to be a type with exactly one value, which would need log2(1) bits to reprresent it, i.e., zero. The report also left a number of things undefined. An early draft of the report went on to specify 'undefined' as meaning anything from a reasonable continuation of the computation to 'indescribable chaos'. -- hendrik ____________________ Racket Users list: http://lists.racket-lang.org/users
