[r6rs-discuss] "Unspecified"

From: John Cowan <cowan>
Date: Fri Sep 22 15:51:58 2006

Sam TH scripsit:

> That is, should (if #f #f) return a particular value, or not. It seems
> that the current name for the value returned by that expression is a
> compromise between those who want the result to be genuinely
> unspecified, and those who want a particular value.

Indeed. It seems, however, that all Schemes (exceptions?) actually do
provide a particular value, and that that value might as well be
standardized.

> Once this question is resolved, the other questions seem much easier,
> and mostly just a question of naming. The value could be named void, or
> unit, or nil, or empty, or no-information, with appropriate
> constructors, predicates, external representations.

I'd say the only remaining question of substance is whether to have an
external representation or not.

-- 
John  Cowan  http://ccil.org/~cowan   cowan_at_ccil.org
'My young friend, if you do not now, immediately and instantly, pull
as hard as ever you can, it is my opinion that your acquaintance in the
large-pattern leather ulster' (and by this he meant the Crocodile) 'will
jerk you into yonder limpid stream before you can say Jack Robinson.'
        --the Bi-Coloured-Python-Rock-Snake
Received on Fri Sep 22 2006 - 15:51:53 UTC

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