ijoshsmith

/// Converts an `EncodedMessage` to an alternate representation.
struct MorseTransformation<T> {
    let dot, dash, markSeparator, symbolSeparator, termSeparator: T
    
    func apply(to encodedMessage: EncodedMessage) -> [T] {
        return encodedMessage.apply(self)
    }
}

private extension EncodedMessage {

ijoshsmith

enum TransmissionState {
    typealias RelativeDuration = Int
    case On(RelativeDuration)
    case Off(RelativeDuration)
    
    static func createStates(from encodedMessage: EncodedMessage) 
        -> [TransmissionState] {
        let transformation = MorseTransformation(
            dot:             TransmissionState.On(1),
            dash:            TransmissionState.On(3),

ijoshsmith

func createMorseCodeText(from encodedMessage: EncodedMessage) -> String {
    let transformation = MorseTransformation(
        dot:             ".",
        dash:            "-",
        markSeparator:   "",
        symbolSeparator: " ",
        termSeparator:   "\n")
    let characters = transformation.apply(to: encodedMessage)
    return characters.joinWithSeparator("")
}

ijoshsmith

/// Represents an entire Morse encoded message.
struct EncodedMessage { let encodedTerms: [EncodedTerm] }

/// Represents a word or number consisting of Morse code symbols.
struct EncodedTerm { let symbols: [Symbol] }

/// Represents a character encoded with Morse code marks.
struct Symbol { let marks: [Mark] }

/// Represents an individual component of a Morse code symbol.

ijoshsmith

func findAnagramsIn(words: [String]) -> [[String]] {
    var signatureToAnagrams = [String: [String]]()
    for word in words {
        let signature = String(word.characters.sort())
        if let anagrams = signatureToAnagrams[signature] {
            signatureToAnagrams[signature] = anagrams + [word]
        }
        else {
            signatureToAnagrams[signature] = [word]
        }

ijoshsmith

  Dy MxT   MnT   AvT   HDDay  AvDP 1HrP TPcpn WxType PDir AvSp Dir MxS SkyC MxR MnR AvSLP

   1  88    59    74          53.8       0.00 F       280  9.6 270  17  1.6  93 23 1004.5
   2  79    63    71          46.5       0.00         330  8.7 340  23  3.3  70 28 1004.5
   3  77    55    66          39.6       0.00         350  5.0 350   9  2.8  59 24 1016.8
   4  77    59    68          51.1       0.00         110  9.1 130  12  8.6  62 40 1021.1
   5  90    66    78          68.3       0.00 TFH     220  8.3 260  12  6.9  84 55 1014.4
   6  81    61    71          63.7       0.00 RFH     030  6.2 030  13  9.7  93 60 1012.7
   7  73    57    65          53.0       0.00 RF      050  9.5 050  17  5.3  90 48 1021.8
   8  75    54    65          50.0       0.00 FH      160  4.2 150  10  2.6  93 41 1026.3

ijoshsmith

extension Dictionary where Value: Equatable {
    /// Returns all keys mapped to the specified value.
    /// ```
    /// let dict = ["A": 1, "B": 2, "C": 3]
    /// let keys = dict.keysForValue(2)
    /// assert(keys == ["B"])
    /// assert(dict["B"] == 2)
    /// ```
    func keysForValue(value: Value) -> [Key] {
        return flatMap { (key: Key, val: Value) -> Key? in

ijoshsmith

//
//  main.swift
//  HigherOrderFunctions
//
//  Created by Joshua Smith on 12/6/15.
//  Copyright © 2015 iJoshSmith. All rights reserved.
//

/*
This file contains simple implementations of several 

ijoshsmith

import Foundation

/**
Returns a compacted array, with repeated values coalesced.
Example: [a, a, b, c, c, c] yields [(a, 2), (b, 1), (c, 3)]
*/
func compressArray<T: Comparable>(input: [T]) -> [(T, Int)] {
    // TODO - implement this function
    return []
}

ijoshsmith

> foldr (-) 0 [3, 2, 1]
2
 
> (3 - (2 - (1 - 0)))
2
 
> foldl (-) 0 [3, 2, 1]
-6
 
> (((0 - 3) - 2) - 1)