Fibonacci Sequence in Elm

01-fib.elm

fib x = 
  case x of 
    0 -> 1 
    1 -> 1 
    _ -> fib (x-1) + fib (x-2)

ml x = 
  List.range 1 x
 
fibs x = 
  List.map fib (ml x)

02-fibs.elm

import Html exposing (text)
import Html.App exposing (beginnerProgram)

main = 
  beginnerProgram { model = model, view = view, update = update }

model = 10

view model = 
  text (toString (fib model))

fib x = 
  case x of 
    0 -> 1 
    1 -> 1 
    _ -> fib (x-1) + fib (x-2)

update model =
  model

03-fibs.elm

import Html exposing (text, br, button, div, h2, input, p)
import Html.App exposing (beginnerProgram)
import Html.Events exposing (onClick)

main = 
  beginnerProgram { model = model, view = view, update = update }

model = 0

type Msg = Increment | Decrement

view model = 
  div [] [
    h2 [] [text "Fibonnaci"],
    br [] [],
    button [onClick Increment] [text "+"],
    br [] [],
    text (toString (model)),
    br [] [],
    button [onClick Decrement] [text "-"],
    p [] [
      text ("Fibonacci Number is " ++ toString(fib model))
    ]
  ]

fib x = 
  case x of 
    0 -> 1 
    1 -> 1 
    _ -> fib (x-1) + fib (x-2)

update msg model =
  case msg of
    Increment -> model + 1
    Decrement -> if model == 0 then model else model - 1