Re: [Haskell-cafe] how to calculate the sum of list of lists?

Miranda Kajtazi wrote:

Help,

How to calculate the sum of list of lists in Haskell?

Do you mean something of the form Num a => [[a]] -> a ? If so, this should do it: Prelude> let foo = sum . concat Prelude> foo [[1,2,3],[4,5]] 15 Cheers, Maxime