On Fri, Jan 14, 2011 at 8:42 AM, Daniel Weinreb dlw@itasoftware.com wrote:
If you have a function that is a predicate, in the sense that the function's contract says that its value should be interpreted as being either false or true, do you think it's better to code it so that it always returns "t" for the true case?
I've never bothered.
Of course I'm also one of these people who routinely use AND and OR to return non-boolean values, which apparently a lot of people dislike (it's specifically contravened in Peter Norvig's style guide, for instance).
BTW I prefer the trailing question mark convention over "-p". Scheme uses the question mark, but I'm not sure the convention originated there -- I think it may actually have started in the InterLisp community. Does anyone know?
-- Scott