PureScript by Example - 5.9 Named Patterns - Exercise 1,3 Solutions

NamedPatterns.purs

module NamedPatterns where

import Prelude

-- Boilerplate code provided in 5.8 Nested Patterns of PureScript by Example
type Address = { street :: String, city :: String }
type Person = { name :: String, address :: Address }

-- Exercise 1
sameCity :: Person -> Person -> Boolean
sameCity { address: { city: x } } { address: { city: y } } = x == y

-- Exercise 3
fromSingleton :: forall a. a -> Array a -> a
fromSingleton _ [x] = x
fromSingleton x _ = x