how does 'undefined' work in Haskell

Question

I\'m curious about the \'undefined\' value in Haskell. Its interesting because you can put it just about anywhere, and Haskell will be happy. The following are all a-ok

Answer 1

If I try undefined in GHCi, I get an exception:

Prelude> undefined
*** Exception: Prelude.undefined

Therefore, I suppose that it's just implemented as throwing an exception:
http://www.haskell.org/ghc/docs/latest/html/libraries/base/Control-Exception.html#g:2