Episode 21

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "0018-environment-pt2/Vendor/swift-overture"]
 	path = 0018-environment-pt2/Vendor/swift-overture
 	url = https://github.com/pointfreeco/swift-overture.git
+[submodule "0021-playground-driven-development/Vendor/swift-overture"]
+	path = 0021-playground-driven-development/Vendor/swift-overture
+	url = https://github.com/pointfreeco/swift-overture.git

0021-playground-driven-development/PointFree.playground/Contents.swift

@@ -0,0 +1,5 @@
+import PointFreeFramework
+import PlaygroundSupport
+
+let vc = EpisodeListViewController()
+PlaygroundPage.current.liveView = vc

0021-playground-driven-development/PointFree.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='ios' executeOnSourceChanges='false'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

0021-playground-driven-development/PointFree/PointFree/AppDelegate.swift

@@ -0,0 +1,19 @@
+import PointFreeFramework
+import UIKit
+
+@UIApplicationMain
+class AppDelegate: UIResponder, UIApplicationDelegate {
+
+  let window = UIWindow()
+
+  func application(
+    _ application: UIApplication,
+    didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?
+    ) -> Bool {
+
+    self.window.rootViewController = EpisodeListViewController()
+    self.window.makeKeyAndVisible()
+
+    return true
+  }
+}

0021-playground-driven-development/PointFree/PointFree/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -0,0 +1,98 @@
+{
+  "images" : [
+    {
+      "idiom" : "iphone",
+      "size" : "20x20",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "20x20",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "29x29",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "29x29",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "40x40",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "40x40",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "60x60",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "60x60",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "20x20",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "20x20",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "29x29",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "29x29",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "40x40",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "40x40",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "76x76",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "76x76",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ipad",
+      "size" : "83.5x83.5",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "ios-marketing",
+      "size" : "1024x1024",
+      "scale" : "1x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

0021-playground-driven-development/PointFree/PointFree/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

0021-playground-driven-development/PointFree/PointFree/Base.lproj/LaunchScreen.storyboard

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="13122.16" systemVersion="17A277" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="13104.12"/>
+        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                        <viewLayoutGuide key="safeArea" id="6Tk-OE-BBY"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+</document>

0021-playground-driven-development/PointFree/PointFree/Info.plist

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

0021-playground-driven-development/PointFree/PointFreeFramework/Info.plist

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>FMWK</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>$(CURRENT_PROJECT_VERSION)</string>
+	<key>NSPrincipalClass</key>
+	<string></string>
+</dict>
+</plist>

0021-playground-driven-development/PointFree/PointFreeFramework/Model.swift

@@ -0,0 +1,53 @@
+import Foundation
+
+public struct Episode {
+  public let blurb: String
+  public let posterImageUrl: String
+  public let publishedAt: Date
+  public let sequence: Int
+  public let subscriberOnly: Bool
+  public let title: String
+}
+
+public let episodes: [Episode] = [
+  .init(
+    blurb: """
+What does the Swift type system have to do with algebra? A lot! We’ll begin to explore this correspondence and see how it can help us create type-safe data structures that can catch runtime errors at compile time.
+""",
+    posterImageUrl: "https://d1hf1soyumxcgv.cloudfront.net/0002-side-effects/0002-poster.jpg",
+    publishedAt: Date(timeIntervalSince1970: 1_519_045_951),
+    sequence: 4,
+    subscriberOnly: true,
+    title: "Algebraic Data Types"
+  ),
+  .init(
+    blurb: """
+Side effects: can’t live with ’em; can’t write a program without ’em. Let’s explore a few kinds of side effects we encounter every day, why they make code difficult to reason about and test, and how we can control them without losing composition.
+""",
+    posterImageUrl: "https://d1hf1soyumxcgv.cloudfront.net/0002-side-effects/0002-poster.jpg",
+    publishedAt: Date(timeIntervalSince1970: 1_517_811_069),
+    sequence: 3,
+    subscriberOnly: false,
+    title: "Side Effects"
+  ),
+  .init(
+    blurb: """
+Our first episode is all about functions! We talk a bit about what makes functions special, contrasting them with the way we usually write code, and have some exploratory discussions about operators and composition.
+""",
+    posterImageUrl: "https://d1hf1soyumxcgv.cloudfront.net/0001-functions/0001-poster.jpg",
+    publishedAt: Date(timeIntervalSince1970: 1_517_206_269),
+    sequence: 2,
+    subscriberOnly: false,
+    title: "Functions"
+  ),
+  .init(
+    blurb: """
+Point-Free is here, bringing you videos covering functional programming concepts using the Swift language. Take a moment to hear from the hosts about what to expect from this new series.
+""",
+    posterImageUrl: "https://d1hf1soyumxcgv.cloudfront.net/0000-introduction/0000-poster.jpg",
+    publishedAt: Date(timeIntervalSince1970: 1_517_206_269),
+    sequence: 0,
+    subscriberOnly: false,
+    title: "We launched!"
+  ),
+]

0021-playground-driven-development/PointFree/PointFreeFramework/PointFreeFramework.h

@@ -0,0 +1,19 @@
+//
+//  PointFreeFramework.h
+//  PointFreeFramework
+//
+//  Created by Stephen Celis on 7/20/18.
+//  Copyright © 2018 Point-Free. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+//! Project version number for PointFreeFramework.
+FOUNDATION_EXPORT double PointFreeFrameworkVersionNumber;
+
+//! Project version string for PointFreeFramework.
+FOUNDATION_EXPORT const unsigned char PointFreeFrameworkVersionString[];
+
+// In this header, you should import all the public headers of your framework using statements like #import <PointFreeFramework/PublicHeader.h>
+
+

0021-playground-driven-development/PointFree/PointFreeFramework/StyleGuide.swift

@@ -0,0 +1,82 @@
+import Foundation
+import UIKit
+import Overture
+
+extension CGFloat {
+  static func pf_grid(_ n: Int) -> CGFloat {
+    return CGFloat(n) * 4
+  }
+}
+
+let generousMargins =
+  mut(\UIView.layoutMargins, .init(top: .pf_grid(6), left: .pf_grid(6), bottom: .pf_grid(6), right: .pf_grid(6)))
+
+let autoLayoutStyle = mut(\UIView.translatesAutoresizingMaskIntoConstraints, false)
+
+let verticalStackView = mut(\UIStackView.axis, .vertical)
+
+let baseStackViewStyle = concat(
+  generousMargins,
+  mut(\UIStackView.spacing, .pf_grid(3)),
+  verticalStackView,
+  mut(\.isLayoutMarginsRelativeArrangement, true),
+  autoLayoutStyle
+)
+
+let bolded: (inout UIFont) -> Void = { $0 = $0.bolded }
+
+let baseTextButtonStyle = concat(
+  mut(\UIButton.titleLabel!.font, UIFont.preferredFont(forTextStyle: .subheadline)),
+  mver(\UIButton.titleLabel!.font!, bolded)
+)
+
+extension UIButton {
+  var normalTitleColor: UIColor? {
+    get { return self.titleColor(for: .normal) }
+    set { self.setTitleColor(newValue, for: .normal) }
+  }
+}
+
+let secondaryTextButtonStyle = concat(
+  baseTextButtonStyle,
+  mut(\.normalTitleColor, .black)
+)
+
+let primaryTextButtonStyle = concat(
+  baseTextButtonStyle,
+  mut(\.normalTitleColor, .pf_purple)
+)
+
+let baseButtonStyle = concat(
+  baseTextButtonStyle,
+  mut(\.contentEdgeInsets, .init(top: .pf_grid(2), left: .pf_grid(4), bottom: .pf_grid(2), right: .pf_grid(4)))
+)
+
+func roundedStyle(cornerRadius: CGFloat) -> (UIView) -> Void {
+  return concat(
+    mut(\.layer.cornerRadius, cornerRadius),
+    mut(\.layer.masksToBounds, true)
+  )
+}
+
+let baseRoundedStyle = roundedStyle(cornerRadius: 6)
+
+let baseFilledButtonStyle = concat(
+  baseButtonStyle,
+  baseRoundedStyle
+)
+
+extension UIButton {
+  var normalBackgroundImage: UIImage? {
+    get { return self.backgroundImage(for: .normal) }
+    set { self.setBackgroundImage(newValue, for: .normal) }
+  }
+}
+
+let primaryButtonStyle = concat(
+  baseFilledButtonStyle,
+  mut(\.normalBackgroundImage, .from(color: .pf_purple)),
+  mut(\.normalTitleColor, .white)
+)
+
+let smallCapsLabelStyle = mut(\UILabel.font, UIFont.preferredFont(forTextStyle: .caption1).smallCaps)