> If we want to be pedantic, there is no such thing as a pure JavaScript function. If the stack is full, ...
Under this definition, Haskell has no pure functions either.
Under this definition, Haskell has no pure functions either.
Prelude> undefined
*** Exception: Prelude.undefined
Prelude> let x 2 = 4 in x 1
*** Exception: <interactive>:7:5-11: Non-exhaustive patterns in function x
Prelude> :t undefined
undefined :: t
Prelude> :t let x 2 = 4 in x
let x 2 = 4 in x :: (Eq a, Num a, Num a1) => a -> a1
No it's not because you can't check for bottom (purely) and thus you can't use it as a flag or sentinel value.
Only at definition site, not use site, for both better and worse.