On Dec 15, 2011, at 12:52 PM, Brandon Allbery wrote:
> These statements are not mutually logically consistent, and leave me
> wondering if Applicative and/or Alternative have been fully thought out.
Oh, that particular question is *super*-easy to answer: based on what I've
been reading, they *weren't* fully thought out. ;-) It would seem that they
were tacked onto the base libraries because people had learned from experience
(mostly while writing parser libraries, in the case of Alternative) that they
were sufficiently useful in a general setting that doing this made sense at the
time. (I am exaggerating a little but that's the general idea.)
Mind you, this was not meant to be a criticism at all --- design is an
iterative process where at each step you make the best decision that you can
based on the available information, hopefully setting yourself up so that at
the next step you can make an even better decision. :-) What we seem to be
learning now is simply that things that may have seemed obvious years ago are
not as obvious now as they had seemed to be at the time.
Cheers,
Greg
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