[Haskell-cafe] Nice way to calculate character frequency in a
ahey at iee.org
Tue Oct 25 07:23:25 EDT 2005
On Tuesday 25 Oct 2005 10:40 am, Charles SDudu wrote:
> Hello, I need to calculate the frequency of each character in a String.
Something like this maybe (untested code ahead)..
calc :: String -> [(Char,Int)]
calc cs = asListL (genAsTree cc [(c,1) | c <- cs])
where cc (c0,n0) (c1,n1) =
case compare c0 c1 of
LT -> Lt
GT -> Gt
EQ -> let n=n0+n1
in n `seq` Eq (c0,n)
But this uses packages you have to install yourself..
You could probably do something similar with Data.Map
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