[Haskell-cafe] Maybe and partial functions

[Dougal Stanton]

The Maybe construction is very useful for explicitly handling
circumstances where the function cannot produce a sensible answer.

But how far should this notion be taken? When you're writing a function
which you realise may not produce what you want, in what circumstances
would you use a Maybe, and when would you just throw an error?

I'm wondering both in terms of good engineering practise and also for
correctness. Should elementary partial functions like

> 5 `div` 0

or

> head []

return Nothing? I guess it's a bit of a silly suggestion, but it helps
to highlight why we use Maybe in the first place. So --- where's the
cutoff point in your code?

Cheers,

D.
-- 
Dougal Stanton