[Haskell-cafe] defining last using foldr

Alexteslin alexteslin at yahoo.co.uk
Tue Aug 14 15:51:54 EDT 2007


I am trying to do the exercise which asks to define built-in functions
'last' and 'init' using 'foldr' function, such as last "Greggery Peccary" =

the type for my function is: 

myLast :: [Char] -> Char 

I am not generalizing type so that make it less complicated.  But what ever
i am trying would not work.  The only function type foldr takes as an
argument is either (a->a->a) or (a->b->b) and none of the functions i found
that would match this type from Char to Char.  So in other words should be
(Char->Char-Char).  I can define the function without foldr but that misses
the point of the exercise.  

Any hint will be appreciated,
Thank you 
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