Well, your program is not equivalent to the C++ version, since it
doesn't bail on incorrect input.
2009/1/15 Apfelmus, Heinrich
Jonathan Cast wrote:
reverseDouble = unlines . intro . map show . reverse . map (read :: String -> Double) . takeWhile (/= "end") . words where intro l = ("read " ++ show (length l) ++ " elements") : "elements in reversed order" : l
This can be simplified to
... . map show . reverse . map read . ...
= { map f . reverse = reverse . map f }
... . reverse . map show . map read . ...
= { map f . map g = map (f . g) }
... . reverse . map (show . read) . ...
= { show . read = id }
... . reverse . map id . ...
= { map id = id }
... . reverse . ...
In other words,
reverseDouble = unlines. intro . reverse . takeWhile (/= "end") . words where intro xs = ("read " ++ show (length xs) ++ " elements") : "elements in reversed order" : xs
And the doubles disappeared completely. :)
Regards, H. Apfelmus
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