diff --git a/.travis.yml b/.travis.yml
index ab4289e..c72197f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,20 +1,28 @@
-matrix:
-  include:
-    - os: linux
-      dist: trusty
-      sudo: required
-      language: ruby
-      before_install:
-        - export SWIFT_ARCHIVE_URL="https://swift.org/builds/swift-4.0-release/ubuntu1404/swift-4.0-RELEASE/swift-4.0-RELEASE-ubuntu14.04.tar.gz"
-        - curl ${SWIFT_ARCHIVE_URL} -o ../swift.tar.gz
-        - mkdir ../swift
-        - tar xzf ../swift.tar.gz -C ../swift --strip-components 1
-        - export PATH="$(pwd)/../swift/usr/bin:${PATH}"
-    - os: osx
-      osx_image: xcode9
-      sudo: required
-      language: objective-c
+branches:
+  except:
+    - /^\d+\.\d+\.\d+(-\S*)?$/
 
+os:
+  - linux
+  - osx
+language: generic
+sudo: required
+osx_image: xcode10.2
+dist: xenial
+env:
+  - SWIFT_BUILD_OPTION="-Xswiftc -swift-version -Xswiftc 4"
+  - SWIFT_BUILD_OPTION="-Xswiftc -swift-version -Xswiftc 4.2"
+  - SWIFT_BUILD_OPTION="-Xswiftc -swift-version -Xswiftc 5"
+before_install:
+  - |
+    if [ $(uname) = "Linux" ]; then
+      export SWIFT_ARCHIVE_URL="https://swift.org/builds/swift-5.0-release/ubuntu1604/swift-5.0-RELEASE/swift-5.0-RELEASE-ubuntu16.04.tar.gz"
+      curl ${SWIFT_ARCHIVE_URL} -o ../swift.tar.gz
+      mkdir ../swift
+      tar xzf ../swift.tar.gz -C ../swift --strip-components 2
+      export PATH="$(dirname $(pwd))/swift/bin:$PATH"
+    fi
 script:
-  - swift build
-  - swift test
+  - swift build ${SWIFT_BUILD_OPTION}
+  - swift build --configuration release ${SWIFT_BUILD_OPTION}
+  - swift test ${SWIFT_BUILD_OPTION}
diff --git a/Package.swift b/Package.swift
index 3727227..f2a2d69 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,15 +1,23 @@
-// swift-tools-version:4.0
+// swift-tools-version:5.0
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 
 let package = Package(
   name: "TimeSpecification",
-  products: [.library(name: "SwiftTimeSpecification", type:.dynamic, targets: ["TimeSpecification"])],
-  dependencies: [],
-  targets: [
-    .target(name: "TimeSpecification", dependencies: [], path:".", sources:["Sources"]),
-    .testTarget(name: "TimeSpecificationTests", dependencies: ["TimeSpecification"])
+  products: [
+    // Products define the executables and libraries produced by a package, and make them visible to other packages.
+    .library(name: "SwiftTimeSpecification", type: .dynamic, targets: ["TimeSpecification"]),
   ],
-  swiftLanguageVersions:[3, 4]
+  dependencies: [
+    // Dependencies declare other packages that this package depends on.
+  ],
+  targets: [
+    // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+    // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+    .target(name: "TimeSpecification", dependencies: []),
+    .testTarget(name: "TimeSpecificationTests", dependencies: ["TimeSpecification"]),
+  ],
+  swiftLanguageVersions: [.v4, .v4_2, .v5]
 )
+
diff --git a/Package@swift-3.swift b/Package@swift-3.swift
deleted file mode 100644
index b3bd2ce..0000000
--- a/Package@swift-3.swift
+++ /dev/null
@@ -1,8 +0,0 @@
-// swift-tools-version:3.1
-
-import PackageDescription
-
-let package = Package(
-    name: "TimeSpecification",
-    swiftLanguageVersions:[3]
-)
diff --git a/README.md b/README.md
index a522704..d0c024c 100644
--- a/README.md
+++ b/README.md
@@ -1,42 +1,29 @@
 # What is SwiftTimeSpecification?
-SwiftTimeSpecification is an implementation of `struct timespec` (`struct mach_timespec` on OS X) in Swift Programming Language.  
+SwiftTimeSpecification is an implementation of `struct timespec` (`struct mach_timespec` on OS X) in Swift.  
 Its prototype is [YOCKOW's Gist](https://gist.github.com/YOCKOW/12d9607cb30f40b79fb2).  
 
-[![Build Status](https://travis-ci.org/YOCKOW/SwiftTimeSpecification.svg?branch=master)](https://travis-ci.org/YOCKOW/SwiftTimeSpecification)
 
-
-## Class, Structure, Enumeration
-```
-public struct TimeSpecification {
-  public var seconds:Int64 = 0
-  public var nanoseconds:Int32 = 0
-  /* ... */
-}
-public enum Clock {
-  case calendar
-  case system
-  
-  public var timeSpecification: TimeSpecification? {
-    /* ... */
-  }
-}
-```
-
-# How to use
-Build and install:  
-`./build-install.rb --install-prefix=/path/to/your/system --install`  
-Then, you can use it in your project:  
-`swiftc ./your/project/main.swift -I/path/to/your/system/include -L/path/to/your/system/lib -lSwiftTimeSpecification`  
-
-# Sample Code
+## Sample Code
 ```
 import TimeSpecification
 
 func time(_ body:() -> Void) {
-  guard let start = Clock.system.timeSpecification else { return }
+  let start = TimeSpecification(clock:.stystem)
   body()
-  guard let end = Clock.system.timeSpecification else { return }
+  let end = TimeSpecification(clock:.stystem)
   let duration = end - start
   print("\(duration)")
 }
 ```
+
+
+# Requirements
+
+- Swift 5 (including compatibility mode for 4, 4.2)
+- macOS or Linux
+
+
+# License
+
+MIT License.  
+See "LICENSE.txt" for more information.
diff --git a/Sources/TimeSpecification.swift b/Sources/TimeSpecification.swift
deleted file mode 100644
index 696df66..0000000
--- a/Sources/TimeSpecification.swift
+++ /dev/null
@@ -1,131 +0,0 @@
-/***************************************************************************************************
- TimeSpecification.swift
-  © 2016-2017 YOCKOW.
-    Licensed under MIT License.
-    See "LICENSE.txt" for more information.
- **************************************************************************************************/
-
-#if os(Linux)
-  import Glibc
-  private typealias CTimeSpec = timespec
-#elseif os(OSX) || os(iOS) || os(watchOS) || os(tvOS)
-  import Darwin
-  private let mach_task_self:() -> mach_port_t = { return mach_task_self_ }
-  private typealias CTimeSpec = mach_timespec_t
-#else
-  // UNKNOWN OS
-#endif
-
-public struct TimeSpecification {
-  public var seconds:Int64 = 0
-  public var nanoseconds:Int32 = 0 {
-    didSet { self.normalize() }
-  }
-  
-  public init(seconds:Int64, nanoseconds:Int32) {
-    self.seconds = seconds
-    self.nanoseconds = nanoseconds
-    self.normalize()
-  }
-  
-  public mutating func normalize() {
-    // `nanoseconds` must be always zero or positive value and less than 1_000_000_000
-    if self.nanoseconds >= 1_000_000_000 {
-      self.seconds += Int64(self.nanoseconds / 1_000_000_000)
-      self.nanoseconds = self.nanoseconds % 1_000_000_000
-    } else if self.nanoseconds < 0 {
-      // For example,
-      //   (seconds:3, nanoseconds:-2_123_456_789)
-      //   -> (seconds:0, nanoseconds:876_543_211)
-      self.seconds += Int64(self.nanoseconds / 1_000_000_000) - 1
-      self.nanoseconds = self.nanoseconds % 1_000_000_000 + 1_000_000_000
-    }
-  }
-}
-
-/// Comparable
-extension TimeSpecification: Comparable {
-  public static func ==(lhs:TimeSpecification, rhs:TimeSpecification) -> Bool {
-    return (lhs.seconds == rhs.seconds && lhs.nanoseconds == rhs.nanoseconds) ? true : false
-  }
-  public static func <(lhs:TimeSpecification, rhs:TimeSpecification) -> Bool {
-    if lhs.seconds < rhs.seconds { return true }
-    if lhs.seconds > rhs.seconds { return false }
-    // then, in the case of (lhs.seconds == rhs.seconds)
-    if (lhs.nanoseconds < rhs.nanoseconds) { return true }
-    return false
-  }
-}
-  
-/// ExpressibleByIntegerLiteral
-extension TimeSpecification: ExpressibleByIntegerLiteral {
-  public typealias IntegerLiteralType = Int64
-  public init(integerLiteral value:Int64) {
-    self.seconds = value
-    self.nanoseconds = 0
-  }
-}
-
-/// ExpressibleByFloatLiteral
-extension TimeSpecification: ExpressibleByFloatLiteral {
-  public typealias FloatLiteralType = Double
-  public init(floatLiteral value:Double) {
-    self.seconds = Int64(floor(value))
-    self.nanoseconds = Int32((value - Double(self.seconds)) * 1.0E+9)
-  }
-}
-
-/// Sum And Difference
-extension TimeSpecification {
-  public static func +(lhs:TimeSpecification, rhs:TimeSpecification) -> TimeSpecification {
-    var result = lhs
-    result.seconds += rhs.seconds
-    result.nanoseconds += rhs.nanoseconds // always normalized
-    return result
-  }
-  public static func -(lhs:TimeSpecification, rhs:TimeSpecification) -> TimeSpecification {
-    var result = lhs
-    result.seconds -= rhs.seconds
-    result.nanoseconds -= rhs.nanoseconds // always normalized
-    return result
-  }
-  public static func +=(lhs:inout TimeSpecification, rhs:TimeSpecification) {
-    lhs = lhs + rhs // always normalized
-  }
-  public static func -=(lhs:inout TimeSpecification, rhs:TimeSpecification) {
-    lhs = lhs - rhs // always normalized
-  }
-}
-
-/* Clock */
-extension TimeSpecification {
-  fileprivate init(_ cts:CTimeSpec) {
-    self.seconds = Int64(cts.tv_sec)
-    self.nanoseconds = Int32(cts.tv_nsec)
-  }
-}
-public enum Clock {
-  case calendar
-  case system
-  
-  public var timeSpecification: TimeSpecification? {
-    var c_timespec:CTimeSpec = CTimeSpec(tv_sec:0, tv_nsec:0)
-    
-    let clock_id:CInt
-    var retval:CInt = -1
-    
-    #if os(Linux)
-      clock_id = (self == .calendar) ? CLOCK_REALTIME : CLOCK_MONOTONIC
-      retval = clock_gettime(clock_id, &c_timespec)
-    #elseif os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
-      var clock_name: clock_serv_t = 0
-      clock_id = (self == .calendar) ? CALENDAR_CLOCK : SYSTEM_CLOCK
-      retval = host_get_clock_service(mach_host_self(), clock_id, &clock_name)
-      guard retval == 0 else { return nil }
-      retval = clock_get_time(clock_name, &c_timespec)
-      _ = mach_port_deallocate(mach_task_self(), clock_name)
-    #endif
-    
-    return (retval == 0) ? TimeSpecification(c_timespec) : nil
-  }
-}
diff --git a/Sources/TimeSpecification/TimeSpecification.swift b/Sources/TimeSpecification/TimeSpecification.swift
new file mode 100644
index 0000000..59e1cff
--- /dev/null
+++ b/Sources/TimeSpecification/TimeSpecification.swift
@@ -0,0 +1,153 @@
+/***************************************************************************************************
+ TimeSpecification.swift
+  © 2016-2019 YOCKOW.
+    Licensed under MIT License.
+    See "LICENSE.txt" for more information.
+ **************************************************************************************************/
+
+#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+import Darwin
+private let mach_task_self:() -> mach_port_t = { return mach_task_self_ }
+private typealias CTimeSpec = mach_timespec_t
+#else
+import Glibc
+private typealias CTimeSpec = timespec
+#endif
+
+/// The representation for the time in nanoseconds.
+public struct TimeSpecification {
+  public var seconds: Int64 = 0
+  private var _nanoseconds: Int32 = 0
+}
+
+extension TimeSpecification {
+  private mutating func _normalize() {
+   //`nanoseconds` must be always zero or positive value and less than 1_000_000_000
+    if self._nanoseconds >= 1_000_000_000 {
+      self.seconds += Int64(self._nanoseconds / 1_000_000_000)
+      self._nanoseconds = self._nanoseconds % 1_000_000_000
+    } else if self._nanoseconds < 0 {
+      // For example,
+      //   (seconds:3, nanoseconds:-2_123_456_789)
+      //   -> (seconds:0, nanoseconds:876_543_211)
+      self.seconds += Int64(self._nanoseconds / 1_000_000_000) - 1
+      self._nanoseconds = self._nanoseconds % 1_000_000_000 + 1_000_000_000
+    }
+  }
+  
+  public var nanoseconds: Int32 {
+    get {
+      return self._nanoseconds
+    }
+    set {
+      self._nanoseconds = newValue
+      self._normalize()
+    }
+  }
+}
+
+extension TimeSpecification {
+  public init(seconds:Int64, nanoseconds:Int32) {
+    self.seconds = seconds
+    self.nanoseconds = nanoseconds // will be normalized
+  }
+}
+
+extension TimeSpecification: Equatable {
+  public static func ==(lhs:TimeSpecification, rhs:TimeSpecification) -> Bool {
+    return lhs.seconds == rhs.seconds && lhs.nanoseconds == rhs.nanoseconds
+  }
+}
+
+extension TimeSpecification: Comparable {
+  public static func < (lhs: TimeSpecification, rhs: TimeSpecification) -> Bool {
+    if lhs.seconds < rhs.seconds { return true }
+    if lhs.seconds > rhs.seconds { return false }
+    // Then, in the case of (lhs.seconds == rhs.seconds) ...
+    return lhs.nanoseconds < rhs.nanoseconds
+  }
+}
+
+extension TimeSpecification: Hashable {
+  public func hash(into hasher:inout Hasher) {
+    hasher.combine(self.seconds)
+    hasher.combine(self.nanoseconds)
+  }
+}
+
+extension TimeSpecification: ExpressibleByIntegerLiteral {
+  public typealias IntegerLiteralType = Int64
+  public init(integerLiteral value: Int64) {
+    self.init(seconds: value, nanoseconds: 0)
+  }
+}
+
+extension TimeSpecification: ExpressibleByFloatLiteral {
+  public typealias FloatLiteralType = Double
+  public init(floatLiteral value:Double) {
+    let double_seconds = floor(value)
+    self.init(seconds: Int64(double_seconds), nanoseconds: Int32((value - double_seconds) * 1.0E+9))
+  }
+}
+
+// sum and difference
+extension TimeSpecification {
+  public static func +(lhs:TimeSpecification, rhs:TimeSpecification) -> TimeSpecification {
+    var result = lhs
+    result.seconds += rhs.seconds
+    result.nanoseconds += rhs.nanoseconds // always normalized
+    return result
+  }
+  
+  public static func -(lhs:TimeSpecification, rhs:TimeSpecification) -> TimeSpecification {
+    var result = lhs
+    result.seconds -= rhs.seconds
+    result.nanoseconds -= rhs.nanoseconds // always normalized
+    return result
+  }
+  
+  public static func +=(lhs:inout TimeSpecification, rhs:TimeSpecification) {
+    lhs = lhs + rhs // always normalized
+  }
+  
+  public static func -=(lhs:inout TimeSpecification, rhs:TimeSpecification) {
+    lhs = lhs - rhs // always normalized
+  }
+}
+
+extension TimeSpecification {
+  public enum Clock {
+    /// Calendar Clock
+    ///
+    /// Note: This means `CLOCK_REALTIME` on Linux, `CALENDAR_CLOCK` on macOS.
+    case calendar
+    
+    /// System Clock
+    ///
+    /// Note: This means `CLOCK_MONOTONIC` on Linux, `SYSTEM_CLOCK` on macOS.
+    case system
+  }
+  
+  private init(_ cts:CTimeSpec) {
+    self.init(seconds:Int64(cts.tv_sec), nanoseconds:Int32(cts.tv_nsec))
+  }
+  
+  /// Initialze with an instance of `Clock`.
+  public init(clock:Clock) {
+    var c_timespec:CTimeSpec = CTimeSpec(tv_sec:0, tv_nsec:0)
+    let clock_id:CInt
+
+    #if os(Linux)
+      clock_id = (clock == .calendar) ? CLOCK_REALTIME : CLOCK_MONOTONIC
+      _ = clock_gettime(clock_id, &c_timespec)
+    #elseif os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
+      var clock_name: clock_serv_t = 0
+      clock_id = (clock == .calendar) ? CALENDAR_CLOCK : SYSTEM_CLOCK
+      _ = host_get_clock_service(mach_host_self(), clock_id, &clock_name)
+      _ = clock_get_time(clock_name, &c_timespec)
+      _ = mach_port_deallocate(mach_task_self(), clock_name)
+    #endif
+
+    self.init(c_timespec)
+  }
+}
diff --git a/Tests/LinuxMain.swift b/Tests/LinuxMain.swift
index 8a75922..6590ab4 100644
--- a/Tests/LinuxMain.swift
+++ b/Tests/LinuxMain.swift
@@ -1,6 +1,8 @@
 import XCTest
-@testable import TimeSpecificationTests
 
-XCTMain([
-    testCase(TimeSpecificationTests.allTests),
-])
+import TimeSpecificationTests
+
+var tests = [XCTestCaseEntry]()
+tests += TimeSpecificationTests.__allTests()
+
+XCTMain(tests)
diff --git a/Tests/TimeSpecificationTests/TimeSpecificationTests.swift b/Tests/TimeSpecificationTests/TimeSpecificationTests.swift
index 6720385..b68095f 100644
--- a/Tests/TimeSpecificationTests/TimeSpecificationTests.swift
+++ b/Tests/TimeSpecificationTests/TimeSpecificationTests.swift
@@ -1,6 +1,6 @@
 /***************************************************************************************************
  SwiftTimeSpecificationTests.swift
-  © 2016-2017 YOCKOW.
+  © 2016-2019 YOCKOW.
     Licensed under MIT License.
     See "LICENSE.txt" for more information.
  **************************************************************************************************/
@@ -11,7 +11,7 @@ import XCTest
 @testable import TimeSpecification
 
 class TimeSpecificationTests: XCTestCase {
-  func testNormalization() {
+  func test_normalization() {
     let N1 = TimeSpecification(seconds:0, nanoseconds:1_234_567_890)
     let N2 = TimeSpecification(seconds:-1, nanoseconds:-1_234_567_890)
     
@@ -19,7 +19,7 @@ class TimeSpecificationTests: XCTestCase {
     XCTAssertTrue(N2.seconds == -3 && N2.nanoseconds == 765_432_110, "Normalization Test 2")
   }
   
-  func testComparison() {
+  func test_comparison() {
     let C1 = TimeSpecification(seconds:100, nanoseconds:100)
     let C2 = TimeSpecification(seconds: 98, nanoseconds:2_000_000_100)
     let C3 = TimeSpecification(seconds:200, nanoseconds:100)
@@ -29,31 +29,22 @@ class TimeSpecificationTests: XCTestCase {
     XCTAssertTrue(C2 < C4, "Comparison Test 3")
   }
   
-  func testIntegerLiteral() {
+  func test_integerLiteral() {
     let I1: TimeSpecification = 100
     let I2: TimeSpecification = -100
     XCTAssertEqual(I1, TimeSpecification(seconds:100, nanoseconds:0), "ExpressibleByIntegerLiteral Test 1")
     XCTAssertEqual(I2, TimeSpecification(seconds:-100, nanoseconds:0), "ExpressibleByIntegerLiteral Test 2")
   }
   
-  func testFloatLiteral() {
+  func test_floatLiteral() {
     let F1: TimeSpecification = 1.1
     XCTAssertEqual(F1, TimeSpecification(seconds:1, nanoseconds:100_000_000), "ExpressibleByFloatLiteral Test 1")
   }
   
-  func testSumAndDifference() {
+  func test_sumAndDifference() {
     let L1 = TimeSpecification(seconds:100, nanoseconds:123_456_789)
     let R1 = TimeSpecification(seconds:100, nanoseconds:987_654_321)
     XCTAssertEqual(L1 + R1, TimeSpecification(seconds:201, nanoseconds:111_111_110), "Sum Test 1")
     XCTAssertEqual(L1 - R1, TimeSpecification(seconds:0, nanoseconds:-864_197_532), "Difference Test 1")
-
   }
-
-  static var allTests = [
-    ("Normalization", testNormalization),
-    ("Comparison", testComparison),
-    ("ExpressibleByIntegerLiteral", testIntegerLiteral),
-    ("ExpressibleByFloatLiteral", testFloatLiteral),
-    ("+/-", testSumAndDifference)
-  ]
 }
diff --git a/Tests/TimeSpecificationTests/XCTestManifests.swift b/Tests/TimeSpecificationTests/XCTestManifests.swift
new file mode 100644
index 0000000..62abb27
--- /dev/null
+++ b/Tests/TimeSpecificationTests/XCTestManifests.swift
@@ -0,0 +1,22 @@
+#if !canImport(ObjectiveC)
+import XCTest
+
+extension TimeSpecificationTests {
+    // DO NOT MODIFY: This is autogenerated, use:
+    //   `swift test --generate-linuxmain`
+    // to regenerate.
+    static let __allTests__TimeSpecificationTests = [
+        ("test_comparison", test_comparison),
+        ("test_floatLiteral", test_floatLiteral),
+        ("test_integerLiteral", test_integerLiteral),
+        ("test_normalization", test_normalization),
+        ("test_sumAndDifference", test_sumAndDifference),
+    ]
+}
+
+public func __allTests() -> [XCTestCaseEntry] {
+    return [
+        testCase(TimeSpecificationTests.__allTests__TimeSpecificationTests),
+    ]
+}
+#endif
diff --git a/build-install.rb b/build-install.rb
deleted file mode 100755
index ac92d48..0000000
--- a/build-install.rb
+++ /dev/null
@@ -1,296 +0,0 @@
-#!/usr/bin/env ruby
-
-=begin
-build-install.rb
-  © 2016-2017 YOCKOW.
-    Licensed under MIT License.
-    See "LICENSE.txt" for more information.
-=end
-
-ModuleName = 'TimeSpecification'
-ModuleVersion = "0.0.0"
-
-# Requirements #####################################################################################
-require 'fileutils'
-require 'json'
-require 'optparse'
-require 'pathname'
-require 'open3'
-require 'shellwords'
-
-# Constants ########################################################################################
-OS = case RbConfig::CONFIG['host_os']
-  when /darwin/i then :macOS
-  when /linux/i then :Linux
-  else :Other
-end
-SharedLibraryPrefix = 'lib'
-SharedLibrarySuffix = (OS == :macOS) ? '.dylib' : '.so'
-ModuleLinkName = 'Swift' + ModuleName
-RootDirectory = Pathname(__FILE__).dirname.expand_path
-
-## Default Values ##
-Defaults = {
-  :swift => Pathname('swift'),
-  :build_directory => Pathname('./.build'),
-  :install => false,
-  :prefix => Pathname('/usr/local'),
-  :debug => false,
-  :skip_build => false,
-  :skip_test => false,
-  :clean => false
-}
-## Options ##
-Options = {
-  :swift => nil,
-  :build_directory => nil,
-  :install => nil,
-  :prefix => nil,
-  :debug => nil,
-  :skip_build => nil,
-  :skip_test => nil,
-  :sdk => nil,
-  :clean => nil
-}
-## Canceled ##
-Canceled = {
-  :debug => nil,
-  :skip_build => nil,
-  :skip_test => nil
-}
-### Qualifications ###
-UnsavableOptions = [:build_directory, :sdk, :clean]
-PathnameOptions = [:swift, :build_directory, :prefix]
-
-# Functions ########################################################################################
-## Error ##
-def failed(message)
-  $stderr.puts("!!ERROR!! #{message}")
-  exit(false)
-end
-
-## Run Shell Script
-def try_exec(command, indent = 0)
-  puts(' ' * indent + "Execute: #{command}")
-  Open3.popen3(command) {|stdin, stdout, stderr, wait_thread|
-    stdin.close
-    stdout.each {|line| $stdout.puts(' ' * indent * 2 + line) }
-    stderr.each {|line| $stderr.puts(' ' * indent * 2 + line) }
-    
-    status = wait_thread.value.exitstatus
-    failed("Command exited with status #{status}") if status != 0
-  }
-end
-
-# Extends Class(es) ################################################################################
-## Pathname ##
-class Pathname
-  def escaped(type = :shell)
-    return Shellwords.shellescape(self.to_s) if type == :shell
-    return self.to_s.gsub(/\$/, '$$').gsub(/\s/, '$\&') if type == :ninja
-    return self.to_s
-  end
-  def exit_if_i_am_file
-    failed("#{self.to_s} is not directory.") if self.exist? && !self.directory?
-  end
-end
-
-# Parse Options ####################################################################################
-OptionParser.new(__FILE__){|parser|
-  parser.on('--swift=PATH',
-            'Path to `swift` which you want to use.') {|path|
-    path = Pathname(path)
-    path += 'swift' if path.directory?
-    Options[:swift] = Pathname(path)
-  }
-  parser.on('--build-dir=PATH', '--build-directory=PATH',
-            'Name of the directory where the build products will be placed. ' +
-            'Default: ' + Defaults[:build_directory].to_s) {|path|
-    Options[:build_directory] = Pathname(path)
-  }
-  
-  parser.on('--install',
-            'Whether to install products or not.') {|value|
-    Options[:install] = value
-  }
-  parser.on('--prefix=PATH', '--install-prefix=PATH',
-            'The installation prefix. (Only used when `--install` is specified.) ' +
-            'Default: ' + Defaults[:prefix].to_s) {|path|
-    Options[:prefix] = Pathname(path)
-    Options[:prefix]= Options[:prefix].expand_path if path =~ /\A~\//
-    if !Options[:prefix].absolute?
-      failed(%Q[The installation prefix must be absolute path.])
-    end
-    Options[:prefix].exit_if_i_am_file
-    Options[:install] = true # install library if prefix is specified.
-  }
-  
-  parser.on('--debug',
-            'Debug builds') {|value|
-    Options[:debug] = value
-  }
-  parser.on('--release',
-            'Release builds; default is on') {|value|
-    Canceled[:debug] = value
-  }
-  
-  parser.on('--skip-build',
-            'Whether to skip building or not.') {|value|
-    Options[:skip_build] = value
-  }
-  parser.on('--do-build',
-            'Cancel skipping building') {|value|
-    Canceled[:skip_build] = value
-  }
-  
-  parser.on('--skip-test',
-            'Whether to skip testing or not.') {|value|
-    Options[:skip_test] = value
-  }
-  parser.on('--do-test',
-            'Cancel skipping testing') {|value|
-    Canceled[:skip_test] = value
-  }
-  
-  parser.on('--clean',
-            'Whether to clean up or not.') {|value|
-    Options[:clean] = value
-  }
-            
-  begin
-    parser.parse!(ARGV)
-  rescue  OptionParser::ParseError  => error
-    failed(error.message + "\n" + parser.help)
-  end
-}
-
-# Determine Options ################################################################################
-UnsavableOptions.each{|key| Options[key] = Defaults[key] if Options[key].nil?}
-
-## Build Directory
-Options[:build_directory] = Defaults[:build_directory] if Options[:build_directory].nil?
-Options[:build_directory] = RootDirectory + Options[:build_directory] if Options[:build_directory].relative?
-Options[:build_directory].exit_if_i_am_file
-FileUtils.rm_r(Options[:build_directory].to_s) if Options[:clean]
-FileUtils.mkdir_p(Options[:build_directory].to_s)
-
-## Save/Read Cache
-cache_json = Options[:build_directory] + 'build_options-cache.json'
-saved_defaults = nil
-if cache_json.exist?
-  saved_defaults = JSON.parse(File.read(cache_json.to_s), {:symbolize_names => true})
-  saved_defaults.each_key{|key|
-    saved_defaults[key] = Pathname(saved_defaults[key]) if PathnameOptions.include?(key)
-  }
-end
-Defaults.each_pair{|key, value|
-  next if UnsavableOptions.include?(key)
-  if Options[key].nil?
-    if !saved_defaults.nil? && !saved_defaults[key].nil?
-      Options[key] = saved_defaults[key]
-    else
-      Options[key] = Defaults[key]
-    end
-  end
-}
-Canceled.each_pair{|key, value|
-  Options[key] = false if !value.nil? && value
-}
-File.write(cache_json.to_s, JSON.dump(Options))
-Options.each_pair {|key, value| Options[key] = Defaults[key] if value.nil? }
-
-# Swift? ###########################################################################################
-failed("#{Options[:swift]} is not found.") if !system(%Q[which #{Options[:swift].escaped()} >/dev/null])
-
-# Build! ###########################################################################################
-configuration = Options[:debug] ? 'debug' : 'release'
-
-binPath = Pathname(%x[#{Options[:swift].escaped()} build --build-path #{Options[:build_directory].escaped()} --configuration #{configuration} --show-bin-path].chomp)
-libFilename = Pathname(SharedLibraryPrefix + ModuleLinkName + SharedLibrarySuffix)
-libPath = binPath + libFilename
-moduleFilename = Pathname(ModuleName + '.swiftmodule')
-modulePath = binPath + moduleFilename
-
-# Build
-if !Options[:skip_build]
-  puts("[Start Building...]")
-  try_exec(["#{Options[:swift].escaped()} build --build-path #{Options[:build_directory].escaped()}",
-           "--configuration #{configuration}",
-           "-Xswiftc -emit-library -Xswiftc -o#{libPath.escaped()}",
-           "-Xswiftc -module-link-name -Xswiftc #{ModuleLinkName}",
-           "-Xswiftc -module-name -Xswiftc #{ModuleName}",
-           "-Xswiftc -emit-module-path -Xswiftc #{modulePath.escaped()}"].join(" "),
-           2)
-  puts()
-end
-
-# Test
-if !Options[:skip_test]
-  puts("[Start Testing...]")
-  if !Options[:debug]
-    $stderr.puts("** WARNING ** No tests will be executed unless debug mode is specified.")
-  else
-    try_exec(["#{Options[:swift].escaped()} test --build-path #{Options[:build_directory].escaped()}",
-              "--configuration #{configuration}"].join(" "), 2)
-  end
-  puts()
-end
-
-# Install
-if Options[:install]
-  puts("[Installing...]")
-  
-  if Options[:debug]
-    $stderr.puts("** WARNING ** DEBUG MODE. Products to be installed may not be optimized.\n")
-  end
-
-  if ModuleVersion =~ /^([0-9]+)\.([0-9]+)\.([0-9]+)(?:\-(.+))?/
-    majorVersion = $1
-    minorVersion = $2
-    patchVersion = $3
-    prereleaseIdentifiers = $4
-    
-    suffixes = [
-      ".#{majorVersion}.#{minorVersion}",
-      ".#{majorVersion}",
-      ""
-    ]
-    if prereleaseIdentifiers
-      suffixes.unshift(".#{majorVersion}.#{minorVersion}.#{patchVersion}")
-    end
-    
-    libInstallDirPath = Options[:prefix] + Pathname('lib')
-    moduleInstallDirPath = Options[:prefix] + Pathname('include')
-    originalLibFilename = Pathname(SharedLibraryPrefix + ModuleLinkName + SharedLibrarySuffix + '.' + ModuleVersion)
-    originalModuleFilename = Pathname(ModuleName + '.swiftmodule' + '.' + ModuleVersion)
-    originalLibInstallPath = libInstallDirPath + originalLibFilename
-    originalModuleInstallPath = moduleInstallDirPath + originalModuleFilename
-    
-    try_exec("mkdir -p #{libInstallDirPath.escaped()}", 2)
-    try_exec("rm -f #{originalLibInstallPath.escaped()}", 2)
-    try_exec("cp -f #{libPath.escaped()} #{originalLibInstallPath.escaped()}", 2)
-    try_exec("mkdir -p #{moduleInstallDirPath.escaped()}", 2)
-    try_exec("rm -f #{originalModuleInstallPath.escaped()}", 2)
-    try_exec("cp -f #{modulePath.escaped()} #{originalModuleInstallPath.escaped()}", 2)
-    
-    suffixes.each_with_index{|suffix, ii|
-      sourceSuffix = (ii == 0) ? ('.' + ModuleVersion) : suffixes[ii - 1]
-      
-      libSourceFilename = Pathname(SharedLibraryPrefix + ModuleLinkName + SharedLibrarySuffix + sourceSuffix)
-      moduleSourceFilename = Pathname(ModuleName + '.swiftmodule' + sourceSuffix)
-      libDestFilename = Pathname(SharedLibraryPrefix + ModuleLinkName + SharedLibrarySuffix + suffix)
-      moduleDestFilename = Pathname(ModuleName + '.swiftmodule' + suffix)
-      
-      libSourcePath = libInstallDirPath + libSourceFilename
-      moduleSourcePath = moduleInstallDirPath + moduleSourceFilename
-      libDestPath = libInstallDirPath + libDestFilename
-      moduleDestPath = moduleInstallDirPath + moduleDestFilename
-      
-      try_exec("ln -fs #{libSourcePath.escaped()} #{libDestPath.escaped}", 2)
-      try_exec("ln -fs #{moduleSourcePath.escaped()} #{moduleDestPath.escaped}", 2)
-    }
-  else
-    $stderr.puts("Invalid Version")
-  end
-end
-