Fix some warnings

XCAssetPacker.xcodeproj/project.pbxproj

@@ -194,7 +194,7 @@
 					4A56D1461DE5B573000B40D8 = {
 						CreatedOnToolsVersion = 8.1;
 						DevelopmentTeam = D92MT22EX5;
-						LastSwiftMigration = 0900;
+						LastSwiftMigration = 1220;
 						ProvisioningStyle = Automatic;
 					};
 					4AD71E7B1EA4CCBA00016A1A = {
@@ -210,6 +210,7 @@
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
 			knownRegions = (
+				English,
 				en,
 			);
 			mainGroup = 4A56D13E1DE5B573000B40D8;
@@ -375,7 +376,7 @@
 				DEVELOPMENT_TEAM = D92MT22EX5;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_SWIFT3_OBJC_INFERENCE = On;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -385,7 +386,7 @@
 				DEVELOPMENT_TEAM = D92MT22EX5;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_SWIFT3_OBJC_INFERENCE = On;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};

XCAssetPacker/CommandLine/CommandLineKit/CommandLine.swift

@@ -130,7 +130,7 @@ public class CommandLine {
    */
   public var maxFlagDescriptionWidth: Int {
     if _maxFlagDescriptionWidth == 0 {
-      _maxFlagDescriptionWidth = _options.map { $0.flagDescription.characters.count }.sorted().first ?? 0
+      _maxFlagDescriptionWidth = _options.map { $0.flagDescription.count }.sorted().first ?? 0
     }
 
     return _maxFlagDescriptionWidth
@@ -306,8 +306,7 @@ public class CommandLine {
         continue
       }
 
-      let skipChars = arg.hasPrefix(longOptionPrefix) ?
-        longOptionPrefix.characters.count : shortOptionPrefix.characters.count
+      let skipChars = arg.hasPrefix(longOptionPrefix) ? longOptionPrefix.count : shortOptionPrefix.count
       let flagWithArg = arg[arg.index(arg.startIndex, offsetBy: skipChars)..<arg.endIndex]
 
       /* The argument contained nothing but ShortOptionPrefix or LongOptionPrefix */
@@ -338,9 +337,9 @@ public class CommandLine {
       }
 
       /* Flags that do not take any arguments can be concatenated */
-      let flagLength = flag.characters.count
+      let flagLength = flag.count
       if !flagMatched && !arg.hasPrefix(longOptionPrefix) {
-        let flagCharactersEnumerator = flag.characters.enumerated()
+        let flagCharactersEnumerator = flag.enumerated()
         for (i, c) in flagCharactersEnumerator {
           for option in _options where option.flagMatch(String(c)) {
             /* Values are allowed at the end of the concatenated flags, e.g.

XCAssetPacker/CommandLine/CommandLineKit/Option.swift

@@ -46,7 +46,7 @@ public class Option {
 
   internal init(_ shortFlag: String?, _ longFlag: String?, _ required: Bool, _ helpMessage: String) {
     if let sf = shortFlag {
-      assert(sf.characters.count == 1, "Short flag must be a single character")
+      assert(sf.count == 1, "Short flag must be a single character")
       assert(Int(sf) == nil && sf.toDouble() == nil, "Short flag cannot be a numeric value")
     }
 

XCAssetPacker/CommandLine/CommandLineKit/StringExtensions.swift

@@ -49,7 +49,7 @@ internal extension String {
     var isNegative: Bool = false
     let decimalPoint = self._localDecimalPoint()
 
-    let charactersEnumerator = self.characters.enumerated()
+    let charactersEnumerator = self.enumerated()
     for (i, c) in charactersEnumerator {
       if i == 0 && c == "-" {
         isNegative = true
@@ -75,7 +75,7 @@ internal extension String {
 
     let doubleCharacteristic = Double(Int(characteristic)!)
     return (doubleCharacteristic +
-      Double(Int(mantissa)!) / pow(Double(10), Double(mantissa.characters.count - 1))) *
+      Double(Int(mantissa)!) / pow(Double(10), Double(mantissa.count - 1))) *
       (isNegative ? -1 : 1)
   }
 
@@ -92,7 +92,7 @@ internal extension String {
     var numSplits = 0
 
     var curIdx = self.startIndex
-    for i in self.characters.indices {
+    for i in self.indices {
       let c = self[i]
       if c == by && (maxSplits == 0 || numSplits < maxSplits) {
         s.append(String(self[curIdx..<i]))
@@ -118,7 +118,7 @@ internal extension String {
    */
   func padded(toWidth width: Int, with padChar: Character = " ") -> String {
     var s = self
-    var currentLength = self.characters.count
+    var currentLength = self.count
 
     while currentLength < width {
       s.append(padChar)
@@ -146,7 +146,7 @@ internal extension String {
     var currentLineWidth = 0
 
     for word in self.split(by: splitBy) {
-      let wordLength = word.characters.count
+      let wordLength = word.count
 
       if currentLineWidth + wordLength + 1 > width {
         /* Word length is greater than line length, can't wrap */

XCAssetPacker/ImageProperties.swift

@@ -82,7 +82,7 @@ struct ImageProperties {
 
 
     static var typesForSuffixes: [(String, ImageType)] {
-        return ImageType.all.flatMap { (type) in
+        return ImageType.all.compactMap { (type) in
             if let suffix = type.suffix {
                 return (suffix, type)
             } else {

XCAssetPacker/SwiftGeneration.swift

@@ -206,8 +206,9 @@ extension String {
 
         self.enumerateSubstrings(in: startIndex..<endIndex, options: .byWords) { (substring, substringRange, _, stop) in
             guard var substring = substring else { return }
-
-            if let firstCharacterOfWord = substring.characters.popFirst() {
+
+            if substring.count > 0 {
+                let firstCharacterOfWord = substring.removeFirst()
                 var firstLetterOfWord = String(firstCharacterOfWord)
                 firstLetterOfWord = isFirstLetter ? firstLetterOfWord.lowercased() : firstLetterOfWord.uppercased()
                 adaptedText += firstLetterOfWord + substring