DonaldKellett

% flatten/2 - Checks whether the second argument is a fully flattened form of the first, both of which are lists
% Caveat - This solution doesn't make use of append/3 as the exercise page explicitly stated but uses append/2 instead (probably not what the author intended) :p

flatten([], []).
flatten([X | List], [X | Flat]) :- \+ is_list(X), flatten(List, Flat).
flatten([X | List], NewFlat) :- is_list(X), flatten(X, XFlat), flatten(List, Flat), append([XFlat, Flat], NewFlat).

DonaldKellett

module CircleArea where

import Prelude
import Math

circleArea :: Number -> Number
circleArea r = pi * r * r

DonaldKellett

module AddressBook where

-- Boilerplate code given in "3. Functions and Records" of "PureScript by Example"

import Prelude

import Control.Plus (empty)
import Data.List (List(..), filter, head, nubBy)
import Data.Maybe (Maybe, isJust)

DonaldKellett

module Recursion where

-- 4.4 Recursion on Arrays of PureScript by Example

import Prelude
import Data.Array.Partial
import Partial.Unsafe

-- Exercise 1
isEven :: Int -> Boolean

DonaldKellett

module MapAndFilter where

-- 4.7 Filtering Arrays of PureScript by Example

import Prelude
import Data.Array

-- Exercise 1
squared :: Array Number -> Array Number
squared = map (\n -> n * n)

DonaldKellett

module Guards where

-- 4.11 Guards of PureScript by Example

-- Boilerplate code provided by PureScript by Example

import Prelude
import Data.Array
import Control.MonadZero (guard)

DonaldKellett

module Folds where

import Prelude
import Data.Foldable
import Data.Array.Partial
import Partial.Unsafe

-- Exercise 1
allTrue :: Array Boolean -> Boolean
allTrue = foldl (&&) true

DonaldKellett

module FileOperations where

-- 4.17 Listing All Files of PureScript by Example
-- N.B. This module relies extensively on a non-standard module Data.Path
--      whose source code can be found on
--      https://github.com/paf31/purescript-book/blob/master/exercises/chapter4/src/Data/Path.purs

import Prelude
import Data.Array
import Partial.Unsafe

DonaldKellett

module Guards where

import Prelude

-- Exercise 1
factorial :: Int -> Int
factorial 0 = 1
factorial n = n * factorial (n - 1)

-- Exercise 2

DonaldKellett

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