記号の組み合わせから矢印の変換候補を追加する

Core/Sources/Core/InputUtils/ArrowSymbolCandidates.swift

@@ -0,0 +1,19 @@
+enum ArrowSymbolCandidates {
+    /// 日本語入力で変わる長音符・全角記号を、矢印の入力パターンとして扱う。
+    static func variants(for reading: String) -> [String] {
+        let normalized = String(reading.map { character -> Character in
+            switch character {
+            case "ー", "ｰ", "－", "−": "-"
+            case "＞": ">"
+            case "＜": "<"
+            default: character
+            }
+        })
+        return switch normalized {
+        case "->", "-->": ["→", "⇒", "➜"]
+        case "<-", "<--": ["←", "⇐", "⇦"]
+        case "<->", "<-->": ["↔", "⇔"]
+        default: []
+        }
+    }
+}

Core/Sources/Core/InputUtils/SegmentsManager.swift

@@ -564,7 +564,7 @@ public final class SegmentsManager {
 
         let leftSideContext = forcedLeftSideContext ?? self.getCleanLeftSideContext(maxCount: ContextLength.conversion)
         let rightSideContext = forcedRightSideContext ?? self.getCleanRightSideContext(maxCount: ContextLength.conversion)
-        let result = self.kanaKanjiConverter.requestCandidates(
+        var result = self.kanaKanjiConverter.requestCandidates(
             self.composingText,
             options: options(
                 leftSideContext: leftSideContext,
@@ -574,6 +574,17 @@ public final class SegmentsManager {
                 requireEnglishPrediction: Config.DebugPredictiveTyping().value ? .manualMix : .disabled
             )
         )
+        let arrowInput = self.composingText.prefixToCursorPosition()
+        let arrowVariants = ArrowSymbolCandidates.variants(for: arrowInput.convertTarget)
+        if !arrowVariants.isEmpty {
+            let existingTexts = Set(result.mainResults.map(\.text))
+            let arrowCandidates = arrowVariants.filter { !existingTexts.contains($0) }.map { text in
+                Candidate(
+                    lastMid: 0,
+                )
+            }
+            result.mainResults.insert(contentsOf: arrowCandidates, at: min(5, result.mainResults.count))
+        }
         self.rawCandidates = result
     }
 

Core/Tests/CoreTests/InputUtilsTests/ArrowSymbolCandidatesTests.swift

@@ -0,0 +1,63 @@
+@testable import Core
+import Foundation
+import KanaKanjiConverterModuleWithDefaultDictionary
+import Testing
+
+@MainActor
+struct ArrowSymbolCandidatesTests {
+    @Test func patterns() {
+        for input in ["ー＞", "ｰ>", "->", "－＞", "−>", "ーー＞"] {
+            #expect(ArrowSymbolCandidates.variants(for: input) == ["→", "⇒", "➜"])
+        }
+        #expect(ArrowSymbolCandidates.variants(for: "＜ー") == ["←", "⇐", "⇦"])
+        #expect(ArrowSymbolCandidates.variants(for: "＜ー＞") == ["↔", "⇔"])
+        for input in ["", "ー", ">", "a->b", "コーヒー＞", "<=", "ー ＞"] {
+            #expect(ArrowSymbolCandidates.variants(for: input).isEmpty)
+        }
+    }
+
+    @Test(arguments: ["→", "⇒", "➜"])
+    func convertAndCommit(expected: String) throws {
+        try withManager { manager in
+            manager.insertAtCursorPosition("ー＞", inputStyle: .direct)
+            for rich in [false, true] {
+                manager.update(requestRichCandidates: rich)
+                manager.requestSetCandidateWindowState(visible: true)
+                guard case .selecting(let choices, _) = manager.getCurrentCandidateWindow(inputState: .selecting) else {
+                    Issue.record("Expected arrow candidates")
+                    return
+                }
+                #expect(choices.filter { $0.text == expected }.count == 1)
+                #expect(choices.contains { $0.text == "ー＞" })
+                if rich {
+                    let candidate = try #require(choices.first { $0.text == expected })
+                    manager.prefixCandidateCommited(candidate, leftSideContext: "")
+                    #expect(manager.isEmpty)
+                }
+            }
+        }
+    }
+
+    @Test func editedPrefixPreservesSuffix() throws {
+        try withManager { manager in
+            manager.insertAtCursorPosition("ー＞あ", inputStyle: .direct)
+            manager.editSegment(count: -1)
+            guard case .selecting(let choices, _) = manager.getCurrentCandidateWindow(inputState: .selecting) else {
+                Issue.record("Expected edited candidates")
+                return
+            }
+            let candidate = try #require(choices.first { $0.text == "⇒" })
+            manager.prefixCandidateCommited(candidate, leftSideContext: "")
+            #expect(manager.convertTarget == "あ")
+        }
+    }
+
+    private func withManager(_ body: (SegmentsManager) throws -> Void) throws {
+        let directory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
+        defer { try? FileManager.default.removeItem(at: directory) }
+        let manager = SegmentsManager(kanaKanjiConverter: .withDefaultDictionary(), applicationDirectoryURL: directory,
+                                      containerURL: nil, context: .init(useZenzai: false))
+        try body(manager)
+    }
+}

README.md

@@ -151,3 +151,7 @@ Thanks to authors!!
 
 ## Acknowledgement
 本プロジェクトは情報処理推進機構(IPA)による[2024年度未踏IT人材発掘・育成事業](https://www.ipa.go.jp/jinzai/mitou/it/2024/koubokekka.html)の支援を受けて開発を行いました。
+
+### 記号の組み合わせから矢印へ変換
+
+`ー＞` / `->` → `→`・`⇒`・`➜`、`＜ー` → `←`・`⇐`・`⇦`、`＜ー＞` → `↔`・`⇔`を候補に追加します。全角・半角の記号に対応し、元の入力も選べます。文節編集中は選択範囲だけを確定します。