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#f = #none ?
- To: firstname.lastname@example.org
- Subject: #f = #none ?
- From: Stavros Macrakis <email@example.com>
- Date: Wed, 18 Nov 1992 10:57:42 -0500
- Sender: firstname.lastname@example.org
Imagine a function which takes an optional argument which is to be
True, False, or Dont-care. Presumably if the argument is omitted, the
value should be Dont-care. How will we encode these values? We can't
use #f for False, because it also means that the argument isn't there.
We could use #t for true, but we'll have to be careful, because all
boolean functions in Dylan allow any non-#f value to represent
So perhaps we'll need to define a new type which takes values
(singletons) True, False, and #f... Seems silly, and error-prone.