Moves the Swift StringUtils class to a Swift package.

McBopomofo.xcodeproj/project.pbxproj

@@ -46,7 +46,6 @@
 		D44FB74A2791B829003C80A6 /* VXHanConvert in Frameworks */ = {isa = PBXBuildFile; productRef = D44FB7492791B829003C80A6 /* VXHanConvert */; };
 		D44FB74D2792189A003C80A6 /* PhraseReplacementMap.cpp in Sources */ = {isa = PBXBuildFile; fileRef = D44FB74B2792189A003C80A6 /* PhraseReplacementMap.cpp */; };
 		D456576E279E4F7B00DF6BC9 /* KeyHandlerInput.swift in Sources */ = {isa = PBXBuildFile; fileRef = D456576D279E4F7B00DF6BC9 /* KeyHandlerInput.swift */; };
-		D45EB5C127A9894C00E28B17 /* StringUtils.swift in Sources */ = {isa = PBXBuildFile; fileRef = D45EB5BF27A9890C00E28B17 /* StringUtils.swift */; };
 		D461B792279DAC010070E734 /* InputState.swift in Sources */ = {isa = PBXBuildFile; fileRef = D461B791279DAC010070E734 /* InputState.swift */; };
 		D47B92C027972AD100458394 /* main.swift in Sources */ = {isa = PBXBuildFile; fileRef = D47B92BF27972AC800458394 /* main.swift */; };
 		D47D73A427A5D43900255A50 /* KeyHandlerBopomofoTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D47D73A327A5D43900255A50 /* KeyHandlerBopomofoTests.swift */; };
@@ -60,6 +59,7 @@
 		D485D3B92796A8A000657FF3 /* PreferencesTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D485D3B82796A8A000657FF3 /* PreferencesTests.swift */; };
 		D485D3C02796CE3200657FF3 /* VersionUpdateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D485D3BF2796CE3200657FF3 /* VersionUpdateTests.swift */; };
 		D4A13D5A27A59F0B003BE359 /* InputMethodController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D4A13D5927A59D5C003BE359 /* InputMethodController.swift */; };
+		D4C9CAB127AAC9690058DFEA /* NSStringUtils in Frameworks */ = {isa = PBXBuildFile; productRef = D4C9CAB027AAC9690058DFEA /* NSStringUtils */; };
 		D4E33D8A27A838CF006DB1CF /* Localizable.strings in Resources */ = {isa = PBXBuildFile; fileRef = D4E33D8827A838CF006DB1CF /* Localizable.strings */; };
 		D4E33D8F27A838F0006DB1CF /* InfoPlist.strings in Resources */ = {isa = PBXBuildFile; fileRef = D4E33D8D27A838F0006DB1CF /* InfoPlist.strings */; };
 		D4E569DC27A34D0E00AC2CEF /* KeyHandler.mm in Sources */ = {isa = PBXBuildFile; fileRef = D4E569DB27A34CC100AC2CEF /* KeyHandler.mm */; };
@@ -169,7 +169,6 @@
 		D44FB74B2792189A003C80A6 /* PhraseReplacementMap.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = PhraseReplacementMap.cpp; sourceTree = "<group>"; };
 		D44FB74C2792189A003C80A6 /* PhraseReplacementMap.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = PhraseReplacementMap.h; sourceTree = "<group>"; };
 		D456576D279E4F7B00DF6BC9 /* KeyHandlerInput.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = KeyHandlerInput.swift; sourceTree = "<group>"; };
-		D45EB5BF27A9890C00E28B17 /* StringUtils.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StringUtils.swift; sourceTree = "<group>"; };
 		D461B791279DAC010070E734 /* InputState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InputState.swift; sourceTree = "<group>"; };
 		D47B92BF27972AC800458394 /* main.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = main.swift; sourceTree = "<group>"; };
 		D47D73A327A5D43900255A50 /* KeyHandlerBopomofoTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = KeyHandlerBopomofoTests.swift; sourceTree = "<group>"; };
@@ -186,6 +185,7 @@
 		D485D3BF2796CE3200657FF3 /* VersionUpdateTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VersionUpdateTests.swift; sourceTree = "<group>"; };
 		D495583A27A5C6C4006ADE1C /* LanguageModelManager+Privates.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "LanguageModelManager+Privates.h"; sourceTree = "<group>"; };
 		D4A13D5927A59D5C003BE359 /* InputMethodController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InputMethodController.swift; sourceTree = "<group>"; };
+		D4C9CAAF27AAC8EC0058DFEA /* NSStringUtils */ = {isa = PBXFileReference; lastKnownFileType = wrapper; name = NSStringUtils; path = Packages/NSStringUtils; sourceTree = "<group>"; };
 		D4E33D8927A838CF006DB1CF /* Base */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = Base; path = Base.lproj/Localizable.strings; sourceTree = "<group>"; };
 		D4E33D8B27A838D5006DB1CF /* en */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = en; path = en.lproj/Localizable.strings; sourceTree = "<group>"; };
 		D4E33D8C27A838D8006DB1CF /* zh-Hant */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = "zh-Hant"; path = "zh-Hant.lproj/Localizable.strings"; sourceTree = "<group>"; };
@@ -214,6 +214,7 @@
 				D427F7A927905E90004A2160 /* TooltipUI in Frameworks */,
 				D47D73C327A7200500255A50 /* FSEventStreamHelper in Frameworks */,
 				D427F76A278C9E29004A2160 /* CandidateUI in Frameworks */,
+				D4C9CAB127AAC9690058DFEA /* NSStringUtils in Frameworks */,
 				D427F7AE27907B8A004A2160 /* NotifierUI in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -272,7 +273,6 @@
 				D4E569DB27A34CC100AC2CEF /* KeyHandler.mm */,
 				D456576D279E4F7B00DF6BC9 /* KeyHandlerInput.swift */,
 				D461B791279DAC010070E734 /* InputState.swift */,
-				D45EB5BF27A9890C00E28B17 /* StringUtils.swift */,
 				D427F76B278CA1BA004A2160 /* AppDelegate.swift */,
 				D44FB74427915555003C80A6 /* Preferences.swift */,
 				D47F7DCF278C0897002F9DD7 /* NonModalAlertWindowController.swift */,
@@ -414,6 +414,7 @@
 				D427F7BF27908EAC004A2160 /* OpenCCBridge */,
 				D44FB7482791B346003C80A6 /* VXHanConvert */,
 				D47D73C027A71FFA00255A50 /* FSEventStreamHelper */,
+				D4C9CAAF27AAC8EC0058DFEA /* NSStringUtils */,
 			);
 			name = Packages;
 			sourceTree = "<group>";
@@ -477,6 +478,7 @@
 				D427F7C027908EFC004A2160 /* OpenCCBridge */,
 				D44FB7492791B829003C80A6 /* VXHanConvert */,
 				D47D73C227A7200500255A50 /* FSEventStreamHelper */,
+				D4C9CAB027AAC9690058DFEA /* NSStringUtils */,
 			);
 			productName = McBopomofo;
 			productReference = 6A0D4EA215FC0D2D00ABF4B3 /* McBopomofo.app */;
@@ -661,7 +663,6 @@
 				D47F7DD3278C1263002F9DD7 /* UserOverrideModel.cpp in Sources */,
 				6A0D4F4515FC0EB100ABF4B3 /* Mandarin.cpp in Sources */,
 				6ACC3D452793701600F1B140 /* ParselessLM.cpp in Sources */,
-				D45EB5C127A9894C00E28B17 /* StringUtils.swift in Sources */,
 				D41355DE278EA3ED005E5CBD /* UserPhrasesLM.cpp in Sources */,
 				6ACC3D3F27914F2400F1B140 /* KeyValueBlobReader.cpp in Sources */,
 				D41355D8278D74B5005E5CBD /* LanguageModelManager.mm in Sources */,
@@ -1350,6 +1351,10 @@
 			isa = XCSwiftPackageProductDependency;
 			productName = FSEventStreamHelper;
 		};
+		D4C9CAB027AAC9690058DFEA /* NSStringUtils */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = NSStringUtils;
+		};
 /* End XCSwiftPackageProductDependency section */
 	};
 	rootObject = 6A0D4E9415FC0CFA00ABF4B3 /* Project object */;

Packages/NSStringUtils/.gitignore

@@ -0,0 +1,7 @@
+.DS_Store
+/.build
+/Packages
+/*.xcodeproj
+xcuserdata/
+DerivedData/
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata

Packages/NSStringUtils/Package.swift

@@ -0,0 +1,28 @@
+// swift-tools-version:5.3
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "NSStringUtils",
+    products: [
+        // Products define the executables and libraries a package produces, and make them visible to other packages.
+        .library(
+            name: "NSStringUtils",
+            targets: ["NSStringUtils"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    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 this package depends on.
+        .target(
+            name: "NSStringUtils",
+            dependencies: []),
+        .testTarget(
+            name: "NSStringUtilsTests",
+            dependencies: ["NSStringUtils"]),
+    ]
+)

Packages/NSStringUtils/README.md

@@ -0,0 +1,3 @@
+# NSStringUtils
+
+A description of this package.

Packages/NSStringUtils/Sources/NSStringUtils/NSStringUtils.swift

@@ -0,0 +1,50 @@
+import Cocoa
+
+public extension NSString {
+
+    /// Converts the index in an NSString to the index in a Swift string.
+    ///
+    /// An Emoji might be compose by more than one UTF-16 code points, however
+    /// the length of an NSString is only the sum of the UTF-16 code points. It
+    /// causes that the NSString and Swift string representation of the same
+    /// string have different lengths once the string contains such Emoji. The
+    /// method helps to find the index in a Swift string by passing the index
+    /// in an NSString.
+    func characterIndex(from utf16Index:Int) -> (Int, String) {
+        let string = (self as String)
+        var length = 0
+        for (i, character) in string.enumerated() {
+            length += character.utf16.count
+            if length > utf16Index {
+                return (i, string)
+            }
+        }
+        return (string.count, string)
+    }
+
+    @objc func nextUtf16Position(for index: Int) -> Int {
+        var (fixedIndex, string) = characterIndex(from: index)
+        if fixedIndex < string.count {
+            fixedIndex += 1
+        }
+        return string[..<string.index(string.startIndex, offsetBy: fixedIndex)].utf16.count
+    }
+
+    @objc func previousUtf16Position(for index: Int) -> Int {
+        var (fixedIndex, string) = characterIndex(from: index)
+        if fixedIndex > 0 {
+            fixedIndex -= 1
+        }
+        return string[..<string.index(string.startIndex, offsetBy: fixedIndex)].utf16.count
+    }
+
+    @objc var count: Int {
+        (self as String).count
+    }
+
+    @objc var split: [NSString] {
+        Array(self as String).map {
+            NSString(string: String($0))
+        }
+    }
+}

Packages/NSStringUtils/Tests/NSStringUtilsTests/NSStringUtilsTests.swift

@@ -0,0 +1,60 @@
+import XCTest
+@testable import NSStringUtils
+
+final class NSStringUtilsTests: XCTestCase {
+    func testNextWith🌳_0() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.nextUtf16Position(for: 0), 2)
+    }
+
+    func testNextWith🌳_1() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.nextUtf16Position(for: 1), 2)
+    }
+
+    func testNextWith🌳_2() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.nextUtf16Position(for: 2), 4)
+    }
+
+    func testNextWith🌳_3() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.nextUtf16Position(for: 3), 4)
+    }
+
+    func testNextWith🌳_4() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.nextUtf16Position(for: 4), 4)
+    }
+
+    func testNextWith🌳_5() {
+        let s = NSString("🌳🌳🌳")
+        XCTAssertEqual(s.nextUtf16Position(for: 4), 6)
+    }
+
+    func testPrevWith🌳_0() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.previousUtf16Position(for: 0), 0)
+    }
+
+    func testPrevWith🌳_1() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.previousUtf16Position(for: 1), 0)
+    }
+
+    func testINextWith🌳_2() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.previousUtf16Position(for: 2), 0)
+    }
+
+    func testINextWith🌳_3() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.previousUtf16Position(for: 3), 0)
+    }
+
+    func testINextWith🌳_4() {
+        let s = NSString("🌳🌳")
+        XCTAssertEqual(s.previousUtf16Position(for: 4), 2)
+    }
+
+}

Source/InputState.swift

@@ -22,6 +22,7 @@
 // OTHER DEALINGS IN THE SOFTWARE.
 
 import Cocoa
+import NSStringUtils
 
 /// Represents the states for the input method controller.
 ///
@@ -244,8 +245,8 @@ class InputState: NSObject {
 
         @objc var userPhrase: String {
             let text = (composingBuffer as NSString).substring(with: markedRange)
-            let exactBegin = StringUtils.convertToCharIndex(from: markedRange.location, in: composingBuffer)
+            let exactBegin = (composingBuffer as NSString).nextUtf16Position(for: markedRange.location)
-            let exactEnd = StringUtils.convertToCharIndex(from: markedRange.location + markedRange.length, in: composingBuffer)
+            let exactEnd = (composingBuffer as NSString).previousUtf16Position(for: markedRange.location)
             let readings = readings[exactBegin..<exactEnd]
             let joined = readings.joined(separator: "-")
             return "\(text) \(joined)"

Source/KeyHandler.mm

@@ -31,6 +31,7 @@
 #import <string>
 
 @import CandidateUI;
+@import NSStringUtils;
 
 // C++ namespace usages
 using namespace std;
@@ -576,7 +577,7 @@ static NSString *const kGraphVizOutputfile = @"/tmp/McBopomofo-visualization.dot
     if ([input isShiftHold]) {
         // Shift + left
         if (currentState.cursorIndex > 0) {
-            NSInteger previousPosition = [StringUtils previousUtf16PositionForIndex:currentState.cursorIndex in:currentState.composingBuffer];
+            NSInteger previousPosition = [currentState.composingBuffer nextUtf16PositionFor:currentState.cursorIndex];
             InputStateMarking *marking = [[InputStateMarking alloc] initWithComposingBuffer:currentState.composingBuffer cursorIndex:currentState.cursorIndex markerIndex:previousPosition readings:[self _currentReadings]];
             marking.tooltipForInputting = currentState.tooltip;
             stateCallback(marking);
@@ -614,7 +615,7 @@ static NSString *const kGraphVizOutputfile = @"/tmp/McBopomofo-visualization.dot
     if ([input isShiftHold]) {
         // Shift + Right
         if (currentState.cursorIndex < currentState.composingBuffer.length) {
-            NSInteger nextPosition = [StringUtils nextUtf16PositionForIndex:currentState.cursorIndex in:currentState.composingBuffer];
+            NSInteger nextPosition = [currentState.composingBuffer nextUtf16PositionFor:currentState.cursorIndex];
             InputStateMarking *marking = [[InputStateMarking alloc] initWithComposingBuffer:currentState.composingBuffer cursorIndex:currentState.cursorIndex markerIndex:nextPosition readings:[self _currentReadings]];
             marking.tooltipForInputting = currentState.tooltip;
             stateCallback(marking);
@@ -842,7 +843,7 @@ static NSString *const kGraphVizOutputfile = @"/tmp/McBopomofo-visualization.dot
             && ([input isShiftHold])) {
         NSUInteger index = state.markerIndex;
         if (index > 0) {
-            index = [StringUtils previousUtf16PositionForIndex:index in:state.composingBuffer];
+            index = [state.composingBuffer previousUtf16PositionFor:index];
             InputStateMarking *marking = [[InputStateMarking alloc] initWithComposingBuffer:state.composingBuffer cursorIndex:state.cursorIndex markerIndex:index readings:state.readings];
             marking.tooltipForInputting = state.tooltipForInputting;
             stateCallback(marking);
@@ -858,7 +859,7 @@ static NSString *const kGraphVizOutputfile = @"/tmp/McBopomofo-visualization.dot
             && ([input isShiftHold])) {
         NSUInteger index = state.markerIndex;
         if (index < state.composingBuffer.length) {
-            index = [StringUtils nextUtf16PositionForIndex:index in:state.composingBuffer];
+            index = [state.composingBuffer nextUtf16PositionFor:index];
             InputStateMarking *marking = [[InputStateMarking alloc] initWithComposingBuffer:state.composingBuffer cursorIndex:state.cursorIndex markerIndex:index readings:state.readings];
             marking.tooltipForInputting = state.tooltipForInputting;
             stateCallback(marking);

Source/StringUtils.swift

@@ -1,79 +0,0 @@
-// Copyright (c) 2022 and onwards The McBopomofo Authors.
-//
-// 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.
-
-import Foundation
-
-/// Utilities to convert the length of an NSString and a Swift string.
-class StringUtils: NSObject {
-
-    /// Converts the index in an NSString to the index in a Swift string.
-    ///
-    /// An Emoji might be compose by more than one UTF-16 code points, however
-    /// the length of an NSString is only the sum of the UTF-16 code points. It
-    /// causes that the NSString and Swift string representation of the same
-    /// string have different lengths once the string contains such Emoji. The
-    /// method helps to find the index in a Swift string by passing the index
-    /// in an NSString.
-    static func convertToCharIndex(from utf16Index: Int, in string: String) -> Int {
-        var length = 0
-        for (i, character) in string.enumerated() {
-            if length >= utf16Index {
-                return i
-            }
-            length += character.utf16.count
-        }
-        return string.count
-    }
-
-    @objc (nextUtf16PositionForIndex:in:)
-    static func nextUtf16Position(for index: Int, in string: String) -> Int {
-        var index = convertToCharIndex(from: index, in: string)
-        if index < string.count {
-            index += 1
-        }
-        let count = string[..<string.index(string.startIndex, offsetBy: index)].utf16.count
-        return count
-    }
-
-    @objc (previousUtf16PositionForIndex:in:)
-    static func previousUtf16Position(for index: Int, in string: String) -> Int {
-        var index = convertToCharIndex(from: index, in: string)
-        if index > 0 {
-            index -= 1
-        }
-        let count = string[..<string.index(string.startIndex, offsetBy: index)].utf16.count
-        return count
-    }
-}
-
-extension NSString {
-    @objc var count: Int {
-        (self as String).count
-    }
-
-    @objc var split: [NSString] {
-        Array(self as String).map {
-            NSString(string: String($0))
-        }
-    }
-}