Interfaces Types for Haskell

What’s the outcome of the following Haskell program? Prelude> map show [1, True, "APLAS"] ERROR: Couldn’t match expected type ‘Bool ’ against inferred type ‘[Char]’ With interface types, we can have Prelude> map show ([1, True, "APLAS"]:: [Show]) ["1","True","\"APLAS\""] Show is an interface type: it stands for some instance of the builtin type class Show Type annotation forces the list elements to have type Show Interfaces Types for Haskell 2 / 1