Is there a way to assign the same value to multiple variables in Haskell? e.g something like this:
h,f = 5
1 Answer
Prelude> let [x, y] = replicate 2 5
Prelude> x
5
Prelude> y
5
Prelude>
You need replicate to "duplicate" a value. In this case, I duplicating 5 twice. [x, y] mean get x and y from a List. That list is [5, 5]. So, you got x = 5 and y = 5.
Well, I never did such behavior in the real world Haskell but you get what you want.
EDIT: We could use repeat function and the feature of lazy evaluation in the Haskell. Thanks to luqui.
Prelude> let x:y:_ = repeat 5
Prelude> x
5
Prelude> y
5
Prelude>
2 Comments
luqui
If you want to avoid the possible pattern match error if you mismatch the length of the list with the number to replicate, use
repeat instead: let x:y:_ = repeat 5. And I, too, have never seen this idiom in the wild, and suspect it to be rather futile for reasons @absolutezero mentions.
wisn
@luqui I forgot that I could use
repeat and the feature of lazy evaluation. Thanks!
h = f = 5.f <- 5 -> h