On Mar 10, 2010, at 12:21 PM, Ketil Malde wrote:
Introducing names means that I need to keep the temporary
definitions in my
head, and I think "takeWhile (<10000)" is as clear as it can get. And
while a name can be misleading (belowLimit is a boolean, no?) or flat
out wrong, the definition has its semantics¹.
I agree that composition chains are acceptable (and preferable) if
they are clear. And I won't argue about wether the example from
LYAHFGG is sufficiently clear in pointfree style (because I'm biased,
to me it is certainly clear).
I do not agree that introducing names locally for compositions is
*always* a bad idea, even if used only once. (Choosing names that are
"misleading or flat out wrong" is of course always a bad idea.)
Named values are just like comments
While you wanted to degrade named values by this statement I think it
can serve as justification. A sensible comment for the example program
might be
-- computes the sum of all odd squares below a certain limit
With the names in the rewritten example this comment is no longer
necessary. I think only an average Haskell programmer understands the
original pointfree program as quickly as this comment.
Good names can help making comments less important.
Sebastian
--
Underestimating the novelty of the future is a time-honored tradition.
(D.G.)
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