Re: [Haskell-cafe] whine and solution about programmers not respecting documentations

29 Jun 2010


      On Tuesday 29 June 2010 12:50:34, Ketil Malde wrote:
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Daniel Fischer  writes:
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An important point of a powerful type system is to model your program
so that only sensible code is legal.
That would be an awesomely powerful type system :)
Heh.  But while we're waiting for it, we can try to use what we got to
eliminate as much non-sensical code as possible.
+1
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...which is a worry my implementation removed by letting the user decide
through partial application.
Aye.
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For a symmetric relation, you needn't care.
But the docs (are interpreted to) say equivalence relation, so woe
betide you if you give it a symmetric but non-transitive or
non-reflexive function!
deleteBy (\x y -> abs (x-y) == 2) 5 [1..5]
grin
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Anyway: I guess the point here is that if all 'deleteBy f x ys' does
with arguments f and x is apply f to x and then use the result, we might
as well feed it that result and eliminate a lot of uncertainity as well
as some documentation all too few of us bother to read.
Full agreement!