callerobertsson/fibonacci.hs

## fibonacci.hs
module Main where

main = do
    print $ map fibN' [1..10]
    print $ fibN' 1001
    print $ length $ show $ fibN' 500000

fibN' 1 = 0
fibN' 2 = 1
fibN' n = iter 0 1 n where
    iter a b 3 = a + b
    iter a b n = iter b (a + b) (n - 1)

## result.md

      
    Raw
  

              result.md
            
          
    Result

A bit slower than the Golang version but a bit more compact and readable code.
$ ghc fibonacci.hs && time ./fibonacci
[0,1,1,2,3,5,8,13,21,34]
43466557686937456435688527675040625802564660517371780402481729089536555417949051890403879840079255169295922593080322634775209689623239873322471161642996440906533187938298969649928516003704476137795166849228875
104494

real    0m10.660s
user    0m10.571s
sys     0m0.085s
	module Main where

	main = do
	print $ map fibN' [1..10]
	print $ fibN' 1001
	print $ length $ show $ fibN' 500000

	fibN' 1 = 0
	fibN' 2 = 1
	fibN' n = iter 0 1 n where
	iter a b 3 = a + b
	iter a b n = iter b (a + b) (n - 1)