RE: [Hugs-users] Avoiding use of the stack

G'day all. Quoting Josef Svenningsson :

In what sense is it wrong, and in what sense does this example show that?

The time that you want to use $! is when you want some argument to some function to be strict. Unfortunately, $! and $ have different associativities to normal function application, requiring you to introduce readability-imparing parentheses if the strict argument is not the last one: testR2' a n = (testR2' $! (a+n)) (n-1) If $! and $ were both left-associative, you could write this instead: testR2' a n = testR2' $! (a+n) $ (n-1) Cheers, Andrew Bromage