import Prelude hiding ((^)) See here: https://wiki.haskell.org/Import Best regards, Paul От: trent shipley Отправлено: 3 марта 2018 г. в 8:25 Кому: beginners@haskell.org Тема: [Haskell-beginners] Overload ^ {- I want to override Prelude.^ (as an academic exercise). Can it be done? How? Trent -} (^) :: Int -> Int -> Int m ^ 0 = 1 m ^ n = m * (m ^ (n-1)) {- Hutton, Graham. Programming in Haskell (p. 263). Cambridge University Press. Kindle Edition. 2016. -} {- Result [1 of 1] Compiling Main ( ex6_3b.hs, interpreted ) ex6_3b.hs:3:16: error: Ambiguous occurrence ‘^’ It could refer to either ‘Prelude.^’, imported from ‘Prelude’ at ex6_3b.hs:1:1 (and originally defined in ‘GHC.Real’) or ‘Main.^’, defined at ex6_3b.hs:2:3 | 3 | m ^ n = m * (m ^ (n-1)) | ^ Failed, no modules loaded. -} -- So I try (^) :: Int -> Int -> Int m Main.^ 0 = 1 m Main.^ n = m * (m Main.^ (n-1)) {- Result Prelude> :reload ex6_3b.hs:2:3: error: Qualified name in binding position: Main.^ | 2 | m Main.^ 0 = 1 | ^^^^^^ [1 of 1] Compiling Main ( ex6_3b.hs, interpreted ) Failed, no modules loaded. -}