「リファクタリング 第2版」Swiftでコーディング その15
リファクタリング 第2版
21-22頁 第1章 ボリューム特典ポイント集計箇所の削除 totalAmount変数の削除
Swift版 main.swift
データ生成、結果表示付き。
import Foundation
makeData()
func playFor(aPerformance:Performance) -> Play {
return plays[aPerformance.playID]!
}
func volumeCreditsFor(aPerformance:Performance) -> Int {
var result = 0
result += max(aPerformance.audience - 30, 0)
if "comedy" == playFor(aPerformance: aPerformance).type {
result += Int(aPerformance.audience / 5)
}
return result
}
func usd(aNumber:Int) -> String {
let format = NumberFormatter()
format.numberStyle = .currency
format.locale = Locale(identifier: "en_US")
return format.string(from: NSNumber(value: aNumber / 100))!
}
func totalVolumeCredits(invoice:Invoice) -> Int {
var result = 0
for perf in invoice.performances {
result += volumeCreditsFor(aPerformance: perf)
}
return result
}
func totalAmount(invoice:Invoice) -> Int {
var result = 0
for perf in invoice.performances {
result += amountFor(aPerformance: perf)
}
return result
}
func statement(invoice:Invoice, plays:Dictionary<String, Play>) -> String {
var result = "Statement for \(invoice.customer)\n"
for perf in invoice.performances {
result += " \(playFor(aPerformance: perf).name): " + usd(aNumber: amountFor(aPerformance: perf)) + " (\(perf.audience) seats)\n"
}
result += "Amount owed is " + usd(aNumber: totalAmount(invoice: invoice)) + "\n"
result += "You earned \(totalVolumeCredits(invoice: invoice)) credits\n"
return result
}
func amountFor(aPerformance:Performance) -> Int {
var result = 0
switch playFor(aPerformance: aPerformance).type {
case "tragedy":
result = 40000
if aPerformance.audience > 30 {
result += 1000 * (aPerformance.audience - 30)
}
case "comedy":
result = 30000
if aPerformance.audience > 20 {
result += 10000 + 500 * (aPerformance.audience - 20)
}
result += 300 * aPerformance.audience
default:
print("error")
}
return result
}
let result = statement(invoice: invoices[0], plays: plays)
print(result)