ijoshsmith

-- Zips together two lists in Haskell.
zip' :: [a] -> [b] -> [(a, b)]
zip' xs     []     = []
zip' []     ys     = []
zip' (x:xs) (y:ys) = (x, y) : zip' xs ys

-- Example usages:
-- zip' "ABCDE" [1,2,3]   …yields…  [('A',1),('B',2),('C',3)]
-- zip' "AB" [1,2,3,4,5]  …yields…  [('A',1),('B',2)]
-- zip' "ABC" []          …yields…  []

ijoshsmith

# I wrote this after watching Dave Thomas review his implementation
# in this presentation: https://www.youtube.com/watch?v=5hDVftaPQwY
 
defmodule MyList do
 
  def encode(list), do: _encode(list, [])
  
  defp _encode([     a, a | tail], acc), do: _encode([  {a, 2} | tail], acc)
  defp _encode([{a, n}, a | tail], acc), do: _encode([{a, n+1} | tail], acc)
  defp _encode([{a, n}, b | tail], acc), do: _encode([       b | tail], [{a, n} | acc])

ijoshsmith

defmodule Money do

  @silver_dollar 100
  @half_dollar    50
  @quarter        25
  @dime           10
  @nickel          5
  @penny           1
  def all_coins, do: [@silver_dollar, @half_dollar, @quarter, @dime, @nickel, @penny]

ijoshsmith

# Elixir (v1.0.3) solution to the FizzBuzz test, defined as:
#
# Write a program that prints the numbers from 1 to 100. But for multiples of three print 
# "Fizz" instead of the number and for the multiples of five print "Buzz". For numbers 
# which are multiples of both three and five print "FizzBuzz".
# Source: http://c2.com/cgi/wiki?FizzBuzzTest
#
# Inspired by programming exercises in the book 'Programming Elixir' by Dave Thomas.

defmodule FizzBuzz do

ijoshsmith

// These methods assume that `self` references a UIViewController instance.

- (void)loadChildViewController:(UIViewController *)viewController
{
    [self addChildViewController:viewController];
    [self.view addSubview:viewController.view];
    [viewController didMoveToParentViewController:self];
}

- (void)unloadChildViewController:(UIViewController *)viewController

ijoshsmith

import Foundation

/** Outputs of the JSONObjectWithData function. */
enum JSONObjectWithDataResult
{
    case Success(AnyObject)
    case Failure(NSError)
}

/** 

ijoshsmith

//
// UPDATE: This gist was rendered obsolete as of
// Xcode 6 Beta 5, which introduced the nil 
// coalescing operator in Swift proper (??).
//

/* Nil-coalescing operator */
infix operator !! {}
func !! <T> (
    value: T?,

ijoshsmith

import UIKit

// The marshal operator is reviewed in this blog post…
// http://ijoshsmith.com/2014/07/05/custom-threading-operator-in-swift/

// Don't ever do something this ridiculous in a real app!
func printMarshalOperator()
{

                                          {p("M")}

ijoshsmith

/** 
Creates a dictionary with an optional 
entry for every element in an array.
*/
func toDictionary<E, K, V>(
    array:       [E],
    transformer: (element: E) -> (key: K, value: V)?)
    -> Dictionary<K, V>
{
    return array.reduce([:]) {

ijoshsmith

extension Array
{
    func crossJoin<E, R>(
        array:  [E],
        joiner: (t: T, e: E) -> R?)
        -> [R]
    {
        return arrayCrossJoin(self, array, joiner)
    }
}