Initial implementation of MonetaryAmount

Author: SoftwareEngineerChris

.gitignore

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+# Xcode
+#
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+## Build generated
+build/
+DerivedData/
+
+## Various settings
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+xcuserdata/
+
+## Other
+*.moved-aside
+*.xccheckout
+*.xcscmblueprint
+**/.DS_Store
+
+## Obj-C/Swift specific
+*.hmap
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+## Playgrounds
+timeline.xctimeline
+playground.xcworkspace
+
+# Swift Package Manager
+#
+# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
+# Packages/
+# Package.pins
+Package.resolved
+.build/
+MonetaryAmount.xcodeproj/
+
+# CocoaPods
+#
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+#
+# Pods/
+#
+# Add this line if you want to avoid checking in source code from the Xcode workspace
+# *.xcworkspace
+
+# Carthage
+#
+# Add this line if you want to avoid checking in source code from Carthage dependencies.
+# Carthage/Checkouts
+
+Carthage/Build
+
+# fastlane
+#
+# It is recommended to not store the screenshots in the git repo. Instead, use fastlane to re-generate the
+# screenshots whenever they are needed.
+# For more information about the recommended setup visit:
+# https://docs.fastlane.tools/best-practices/source-control/#source-control
+
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots/**/*.png
+fastlane/test_output
+
+# Code Injection
+#
+# After new code Injection tools there's a generated folder /iOSInjectionProject
+# https://github.com/johnno1962/injectionforxcode
+
+iOSInjectionProject/
+

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2018 SoftwareEngineerChris
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

MonetaryAmount.podspec

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+Pod::Spec.new do |s|
+  s.name             = 'MonetaryAmount'
+  s.version          = '1.0.0'
+  s.summary          = 'A Swift representation of Money and ISO 4217 Currencies and the manipulation of them'
+
+  s.description      = <<-DESC
+A Swift representation of money / monetary amounts and ISO 4217 currency designations. Supports manipulation
+and combination of monetary amounts of a single or multiple currency. Handles minor units (the exponent, e.g. cents for USD)
+for each currency as specified in the ISO 4217 standard. Simple manipulation includes consolidating / combining 
+amounts. For example with MonetaryAmount, GBP10.50 + USD5.70 + GBP6.50 + USD8.10 consolidated would result in 
+GBP17.00 and USD13.80. MonetaryAmount does not do any FX or conversion of currencies, it keeps each individual 
+currency subtotal separate.
+                       DESC
+
+  s.homepage         = 'https://github.com/SoftwareEngineerChris/MonetaryAmount'
+  s.license          = { :type => 'MIT', :file => 'LICENSE' }
+  s.author           = { 'SoftwareEngineerChris' => '[email protected]' }
+  s.source           = { :git => 'https://github.com/SoftwareEngineerChris/MonetaryAmount.git', :tag => s.version.to_s }
+
+  s.dependency 'RoundedDecimal', '~> 1.1.0'
+
+  s.ios.deployment_target = '10.0'
+  s.osx.deployment_target = '10.9'
+  s.watchos.deployment_target = '3.0'
+  s.tvos.deployment_target = '10'
+  s.swift_version = '5.0'
+
+  s.source_files = 'Sources/MonetaryAmount/*'
+end

Package.resolved

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+// swift-tools-version:5.0
+
+import PackageDescription
+
+let package = Package(
+    name: "MonetaryAmount",
+    products: [
+        .library(
+            name: "MonetaryAmount",
+            type: .static,
+            targets: ["MonetaryAmount"]),
+        .executable(
+            name: "CurrenciesGenerator",
+            targets: ["CurrenciesGenerator"]
+        )
+    ],
+    dependencies: [
+        .package(url: "https://github.com/SoftwareEngineerChris/RoundedDecimal.git", from: "2.1.0"),
+        .package(url: "https://github.com/stencilproject/Stencil.git", from: "0.13.0")
+    ],
+    targets: [
+        .target(
+            name: "MonetaryAmount",
+            dependencies: ["RoundedDecimal"]),
+        .testTarget(
+            name: "MonetaryAmountTests",
+            dependencies: ["MonetaryAmount"]),
+        .target(
+            name: "CurrenciesGenerator",
+            dependencies: ["Stencil"]),
+    ]
+)

Package.swift

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+# MonetaryAmount
+
+A Swift representation of money / monetary amounts and _ISO 4217_ currency designations. Supports manipulation
+and combination of monetary amounts of a single currency or multiple currencies.
+
+Handles minor units (the exponent, e.g. cents for USD) for each currency as specified in the ISO 4217 standard.
+Simple manipulation includes consolidating / combining amounts.
+
+`MonetaryAmount` values that have the _same_ `Currency` will be added together, `MonetaryAmount` values with 
+_unique_ `Currency` values will be added to the result on their own.
+
+### Usage Example
+
+```swift
+let moneyA = 12.00.in(.USD)
+let moneyB = 18.00.in(.USD)
+let moneyC = 6.00.in(.GBP)
+
+// result would equal [30.00.in(.USD), 6.00.in(.GBP)]
+let result = [moneyA, moneyB, moneyC].consolidating(moneyB)
+```
+
+The underlying value for the amount is represented by a `DynamicRoundedDecimal` which
+itself uses the Swift `Decimal` type. `DynamicRoundedDecimal` handles rounding internally
+as declared by the given currency's `minorUnit`.
+
+### Construction
+
+```swift
+// moneyA and moneyB are equal and represent US$28.53
+let moneyA = MonetaryAmount(currency: Currency.USD, value: Decimal(string: "28.529372")!)
+let moneyB = 28.53.in(.USD)
+```
+
+#### Note
+`MonetaryAmount` does not do any FX or conversion of currencies, it keeps each individual
+currency subtotal separate.
+
+#### See Also
+   [Wikipedia Entry for ISO 4217](https://en.wikipedia.org/wiki/ISO_4217)
+

README.md

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+//
+//  main.m
+//  MonetaryAmount
+//
+//  Created by Chris Hargreaves on 10/09/2019.
+//  Copyright © 2019 Software Engineering Limited. All rights reserved.
+//
+
+import Foundation
+import Stencil
+
+private struct CurrencyGenerator {
+    
+    static func main() {
+        // Read all stdin up-front to read CSV data
+        guard let inputCSV = String(bytes: FileHandle.standardInput.readDataToEndOfFile(), encoding: .utf8) else {
+            reportError("Unable to read input. Please pipe into stdin.")
+        }
+        
+        // Pull the currencies out of the CSV data
+        let currencies = CurrencyGenerator.currencyData(csvCurrencyData: inputCSV)
+        
+        // Create the Stencil template context
+        let context = [ "currencies": currencies, "generatedDate": Date() ] as [String : Any]
+        
+        // Load the Stencil template file from disk
+        let environment = Environment(loader: FileSystemLoader(paths: ["templates/"]))
+        
+        // Render the template with the template context
+        guard let rendered = try? environment.renderTemplate(name: "Currencies.swift", context: context) else {
+            reportError("Unable to read Currencies.swift template file")
+        }
+        
+        // Pump the rendered string back out to the stdout
+        FileHandle.standardOutput.write(rendered.data(using: .utf8)!)
+    }
+    
+    private enum CurrencyDataColumn: Int, CaseIterable {
+        
+        case alphaCurrencyCode
+        case minorUnit
+        case currencyName
+    }
+    
+    private struct CurrencyData: Equatable, Hashable {
+        
+        let currencyName: String
+        let alphaCurrencyCode: String
+        let minorUnit: Int
+    }
+    
+    private static func currencyData(csvCurrencyData: String) -> [CurrencyData] {
+        
+        let currencyData = csvCurrencyData
+            .components(separatedBy: "\n")
+            .map { $0.components(separatedBy: ",") }
+            .compactMap { rawData -> CurrencyData? in
+                
+                guard rawData.count == CurrencyDataColumn.allCases.count else {
+                    return nil
+                }
+                
+                return CurrencyData(
+                    currencyName: rawData[CurrencyDataColumn.currencyName.rawValue],
+                    alphaCurrencyCode: rawData[CurrencyDataColumn.alphaCurrencyCode.rawValue],
+                    minorUnit: Int(rawData[CurrencyDataColumn.minorUnit.rawValue])!
+                )
+            }
+        
+        return Array(Set(currencyData))
+            .sorted { $0.alphaCurrencyCode < $1.alphaCurrencyCode }
+    }
+    
+    private static func reportError(_ message: String) -> Never {
+        FileHandle.standardError.write(message.data(using: .utf8)!)
+        exit(-1)
+    }
+}
+
+// MARK: Program Start
+
+CurrencyGenerator.main()