diff --git a/Prelude.hs b/Prelude.hs index a09a300c9cae6d87f152e75274cc48a554dc75b9..44342a0585146dae8c2775c8473ec7b4b69d728a 100644 --- a/Prelude.hs +++ b/Prelude.hs @@ -151,7 +151,8 @@ import GHC.Base import Text.Read import GHC.Enum import GHC.Num -import GHC.Real +import GHC.Real hiding ( gcd ) +import qualified GHC.Real ( gcd ) import GHC.Float import GHC.Show import GHC.Err ( undefined ) @@ -207,3 +208,11 @@ seq _ y = y catch :: IO a -> (IOError -> IO a) -> IO a catch = New.catch +#ifdef __GLASGOW_HASKELL__ +-- | @'gcd' x y@ is the greatest (positive) integer that divides both @x@ +-- and @y@; for example @'gcd' (-3) 6@ = @3@, @'gcd' (-3) (-6)@ = @3@, +-- @'gcd' 0 4@ = @4@. @'gcd' 0 0@ raises a runtime error. +gcd :: (Integral a) => a -> a -> a +gcd 0 0 = error "Prelude.gcd: gcd 0 0 is undefined" +gcd x y = GHC.Real.gcd x y +#endif