Re: [Haskell-cafe] Does an unboxed unit get pushed to the stack?

12 Jan 2023


      On Thu, Jan 12, 2023 at 04:01:48PM +0100, Bertram Felgenhauer via Haskell-Cafe wrote:
...
Tom Ellis wrote:
...
If I define bar and baz as below then, as I understand it, calling baz
requires pushing an argument onto the machine stack.  Is the same true
for baz, or is "calling" baz the same as "calling" foo, i.e. no
argument needs to be pushed?
{-# LANGUAGE MagicHash #-}
    {-# LANGUAGE UnboxedTuples #-}
module Bar where
import GHC.Prim
foo :: Int
    foo = 1
bar :: (# #) -> Int
    bar (# #) = 1
baz :: () -> Int
    baz () = 0
There is more to the story than just arguments. Assuming that nothing
gets inlined
Very helpful, thank you!