RosettaCodeData/Task/Fibonacci-sequence/Haskell/fibonacci-sequence-3.hs

fib x =
  if x < 1
    then 0
    else if x == 1
           then 1
           else fibs !! (x - 1) + fibs !! (x - 2)
  where
    fibs = map fib [0 ..]
September 2017 Update 2017-09-23 10:01:46 +02:00			`fib x =`
			`if x < 1`
			`then 0`
			`else if x == 1`
			`then 1`
			`else fibs !! (x - 1) + fibs !! (x - 2)`
2016 Update 2016-12-05 22:15:40 +01:00			`where`
September 2017 Update 2017-09-23 10:01:46 +02:00			`fibs = map fib [0 ..]`