[Haskell-beginners] shortening code

Michael Mossey mpm at alumni.caltech.edu
Tue Jun 29 23:25:18 EDT 2010

rizwan hudda wrote:
> I have recently started learning haskell, and was trying to write a code 
> for this problem http://www.spoj.pl/problems/KAMIL in haskell. The aim 
> is to write a shortest possible code for the given task. I have 
> previously solved this in c,c++,perl,python.My best was 57 characters 
> using perl. So here's my code in HASKELL:
> main = interact $ unlines. map (show.foldl (\a x-> if null $ filter 
> (==x) "TDLF" then a else a+a) 1) .lines
> It is 107 characters [ non white space and newline ]. I was interested 
> in knowing how i could further optimize the size of this code.

This kind of contest is fun, but I can't help thinking I hope you are 
learning Haskell to appreciate the things that functional programming is 
good at. Real-world Haskell is often more concise than other languages 
because Haskell has mechanisms for eliminating unnecessary and redundant 
code, but Haskell's strength is not winning "shortest program" contests.


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