Sorting an electrosphere with functional programming - elm

functional_chemicals.elm

import Html exposing (text)
import Array

arr =
  Array.fromList [ Array.fromList ["1s2"]
  , Array.fromList ["2s2", "2p6"]
  , Array.fromList ["3s2", "3p6", "3d10"]
  , Array.fromList ["4s2", "4p6", "4d10", "4f14"]
  , Array.fromList ["5s2", "5p6", "5d10", "5f14"]
  , Array.fromList ["6s2", "6p6", "6d10"]
  , Array.fromList ["7s2", "7p6"]
  ]

arr_i coords =
 case coords of
  (x,y) -> case Array.get x arr of
             Just a -> case Array.get y a of
                         Just b -> b
                         Nothing -> "y out of bound"
             Nothing -> "x out of bound"

next_iteration tuple = 
 case tuple of
   (0,0) -> (1,0)
   (x,0) -> (ceiling((x+1)/2),floor((x+1)/2))
   (x,y) -> (x+1,y-1)

iterations list =
 case List.head list of
   Just (6,1) -> list
   Just tuple -> iterations[next_iteration tuple] ++ list
   _ -> iterations [(0,0)]

main = text <| toString <| List.map arr_i ( List.reverse ( iterations [] ) )