PureScript by Example CH6 Exercises

Complex.purs

module Complex where

import  Prelude
import  Data.Eq

newtype Complex = Complex
  { real :: Number
  , imaginary :: Number
  }

instance eqComplex :: Eq Complex where
  eq (Complex { real: r1, imaginary: i1 }) (Complex { real: r2, imaginary: i2 }) = r1 == r2 && i1 == i2

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

Extended.purs

module Extended where

import Data.Ordering (Ordering(..))
import Data.Ord  

import Prelude

data Extended a = Finite a | Infinite

instance eqExtended :: Eq a => Eq (Extended a) where
  eq Infinite Infinite = true
  eq (Finite x) (Finite y)  = eq x y
  eq _ _ = false

instance ordExtended :: Ord a => Ord (Extended a) where
  compare Infinite Infinite = EQ
  compare Infinite _ = GT
  compare _ Infinite = LT
  compare (Finite x) (Finite y) = compare x y
  

NonEmpty.purs

module NonEmpty where
  
import Data.Array
import Data.Eq
import Data.Functor
import Data.Semigroup
import Prelude

data NonEmpty a = NonEmpty a (Array a)

instance eqNonEmpty :: Eq a => Eq (NonEmpty a) where
  eq (NonEmpty e1 arr1) (NonEmpty e2 arr2) = e1 == e2 && arr1 == arr2

instance semigroupNonEmpty :: Semigroup (NonEmpty a) where
  append (NonEmpty e1 arr1) (NonEmpty e2 arr2) = NonEmpty e1 (append arr1 arr2)
 
instance functorNonEmpty :: Functor NonEmpty where
  map f (NonEmpty e arr) = NonEmpty (f e) (map f arr)

Shape.purs

module Shape where
  
import Prelude

import Data.Hashable (hash)

data Point = Point
  { x :: Number
  , y :: Number
  }
  
data Shape
  = Circle Point Number
  | Rectangle Point Number Number
  | Line Point Point
  | Text Point String


instance showPoint :: Show Point where
show (Point { x, y }) = "(" <> show x <> ", " <> show y <> ")"

instance showShape :: Show Shape where
show (Circle point r) = "c = " <> show point <> ", r = " <> show r
show (Rectangle point w h) = "c = " <> show point <> ", w = " <> show w <> ", h = " <> show h
show (Line p1 p2) = "p1 = " <> show p1 <> "p2 = " <> show p2
show (Text point string) = "point = " <> show point <> "text = " <> show string