PureScript by Example - 6.4 Common Type Classes - Exercise 1 Solution

CommonTypeClasses.purs

module CommonTypeClasses where

import Prelude

-- Boilerplate code
newtype Complex = Complex
   { real :: Number
   , imaginary :: Number
   }

-- Exercise 1
instance showComplex :: Show Complex where
  show (Complex { real, imaginary }) =
    "Complex (" <> show real <> ", " <> show imaginary <> ")"

instance eqComplex :: Eq Complex where
  eq (Complex { real, imaginary }) (Complex { real: real', imaginary: imaginary' }) =
    real == real' && imaginary == imaginary'