Use Dictionary default values

[Samasaur1]

I was reading an article about changes introduced in Swift 4 and came across the ability to provide a default value when accessing a dictionary:

let dict = getDict()

let val = dict[“key”] ?? 0
//can be replaced with
let val = dict[“key”, default: 0]

//no big deal, right? Look at this:
dict[“key”] = (dict[“key”] ?? 0) + 1
//becoming
dict[“key”, default: 0] += 1

We could take advantage of this in quite a few places in Dice.Swift, and possibly other places:

DiceKit/Sources/DiceKit/Dice.swift

Line 75 in d67f52f

newDice[d] = (newDice[d] ?? 0) + 1

DiceKit/Sources/DiceKit/Dice.swift

Line 86 in d67f52f

newDice[d] = (newDice[d] ?? 0) + 1

DiceKit/Sources/DiceKit/Dice.swift

Line 110 in d67f52f

newDice[die] = (newDice[die] ?? 0) + count

DiceKit/Sources/DiceKit/Dice.swift

Line 123 in d67f52f

newDice[d] = (newDice[d] ?? 0) + 1

DiceKit/Sources/DiceKit/Dice.swift

Line 136 in d67f52f

newDice[d] = (newDice[d] ?? 0) + 1

DiceKit/Sources/DiceKit/Dice.swift

Line 162 in d67f52f

newDice[die] = (newDice[die] ?? 0) + count

DiceKit/Sources/DiceKit/Dice.swift

Line 199 in d67f52f

dice[sides] = (dice[sides] ?? 0) - 1

DiceKit/Sources/DiceKit/Dice.swift

Line 203 in d67f52f

dice[sides] = (dice[sides] ?? 0) - multiplier

DiceKit/Sources/DiceKit/Dice.swift

Line 215 in d67f52f

dice[sides] = (dice[sides] ?? 0) + 1

DiceKit/Sources/DiceKit/Dice.swift

Line 219 in d67f52f

dice[sides] = (dice[sides] ?? 0) + multiplier

DiceKit/Sources/DiceKit/Dice.swift

Line 229 in d67f52f

dice[sides] = (dice[sides] ?? 0) - 1

DiceKit/Sources/DiceKit/Dice.swift

Line 233 in d67f52f

dice[sides] = (dice[sides] ?? 0) - multiplier

DiceKit/Sources/DiceKit/Dice.swift

Line 399 in d67f52f

newProbs[res + nRes] = (newProbs[res + nRes] ?? .zero) + (chance * nChance)