[Haskell-cafe] Efficiency Question

[Georg Martius]

Hi Daniel,

On Fri, 14 Jan 2005 21:57:25 +0100, Daniel Fischer <daniel.is.fischer at web.de> wrote:

<snip>
> Finally, in several contexts I needed to cons an element to one of a pair of
> lists, so I defined
>
> infixr 5 &,§
             ^^^
Please be aware that you won't find this paragraph symbol on a uk or us keyboard. AFAIK it is just on the german one.

>
> (&) :: a -> ([a],[b]) -> ([a],[b])
> x & (xs,ys) = (x:xs,ys)
>
> (§) :: b -> ([a],[b]) -> ([a],[b])
> y § (xs,ys) = (xs,y:ys).
>
> I find them useful (though I don't like the symbols, if you have any better
> ideas, thx) and for splitAt, (&) saves another reduction per step.

I think these operators should be more related to ":" like ":&" "&:" or similar. However, in my opinion this special cons operators could be just functions with a meaningful name like "consfst" and "conssnd". It would provide much more readability.

  Cheers,
	Georg

-- 

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