这能写得更简洁，并与函数式反应式编程范例相一致吗？

Question

试着学习玻璃钢和榆树。从玻璃钢和榆树的角度看下面的节目"ok“吗？还有什么可以改进的？这个程序可以在这里执行：http://elm-lang.org/try

import Random
import Mouse
data Fruit = Apple | Orange | Banana | Melon | Guava
rand = Random.range 0 4 (Mouse.clicks)
fruit n = if | n == 0 -> Apple
             | n == 1 -> Orange
             | n == 2 -> Banana
             | n == 3 -> Melon
             | otherwise -> Guava
fruitText = toForm <~ (asText <~ (fruit <~ rand))
time = lift (inSeconds . fst) (timestamp (fps 40))
scene dy form = collage 300 300 [move (0, 100 * cos dy) form]
main = lift2 scene time fruitText

Answer 1

迟了两个月，但我还是会尽力回答的。;-)

由于您的rand已经确定了数字将是有效的索引，您的水果，您不必使用这么多，如果情况。其余的在我看来还不错，但我在源代码中做了一些注释。

import Random
import Mouse
-- Sometimes empty lines can improve readability.

data Fruit = Apple | Orange | Banana | Melon | Guava

-- For module global declarations, it is often helpful to
-- explicitly annotate the types.
fruits : [Fruit]
fruits = [Apple, Orange, Banana, Melon, Guava]

-- especially for functions :)
fruit : Int -> Fruit
fruit n = head <| drop n fruits

rand : Signal Int
rand = Random.range 0 ((length fruits) - 1) Mouse.clicks

-- exercise: Try to figure and annotate the remaining types. ;-)
fruitText = toForm <~ (asText <~ (fruit <~ rand))

time = lift (inSeconds . fst) (timestamp (fps 40))

scene dy form = collage 300 300 [move (0, 100 * cos dy) form]

main = lift2 scene time fruitText

btw:较让某人复制粘贴到elm-lang.org/try，向某人显示elm代码要容易一些。

请参阅：http://share-elm.com/sprout/52567327e4b0d6a98b1531c7