Move inspector hints and Fallauswahl path helpers out of ContentView

VisuStruct-iOS/VisuStructCore/Sources/VisuStructCore/Editing/VisuStructDocumentEditing+Multiway.swift

@@ -0,0 +1,22 @@
+import Foundation
+
+extension VisuStructDocumentEditing {
+    /// Innerste **Fallauswahl** (`multiway`), die `path` enthält (oder selbst ist) — für „Fall hinzufügen/entfernen“.
+    public static func multiwayAncestorPath(for path: [Int]?, in doc: VisuStructDocument) -> [Int]? {
+        guard let path, !path.isEmpty else { return nil }
+        for len in stride(from: path.count, through: 1, by: -1) {
+            let prefix = Array(path.prefix(len))
+            if let el = try? element(at: prefix, in: doc),
+               el.type == .fallauswahl {
+                return prefix
+            }
+        }
+        return nil
+    }
+
+    /// Spaltenindex der Fallauswahl, wenn die Auswahl **in** einer Spalte liegt (`[…, fall, spalte, …]`).
+    public static func caseIndex(of selectedPath: [Int]?, inMultiwayAt multiwayPath: [Int]) -> Int? {
+        guard let sp = selectedPath, sp.count > multiwayPath.count else { return nil }
+        return sp[multiwayPath.count]
+    }
+}

VisuStruct-iOS/VisuStructCore/Tests/VisuStructCoreTests/MultiwayPathTests.swift

@@ -0,0 +1,44 @@
+import XCTest
+import VisuStructCore
+
+final class MultiwayPathTests: XCTestCase {
+    /// `[0]` Anweisung, `[1]` Fallauswahl mit zwei Fällen; im zweiten Fall eine innere Fallauswahl `[1, 1, 0]`.
+    private func document() -> VisuStructDocument {
+        let statement = VisuStructElement(type: .anweisung, textLines: ["x = 1"])
+        let inner = VisuStructElement(
+            type: .fallauswahl,
+            textLines: ["y"],
+            cases: [
+                VisuStructCase(name: "1", elements: [statement]),
+                VisuStructCase(name: "default", elements: [statement]),
+            ]
+        )
+        let outer = VisuStructElement(
+            type: .fallauswahl,
+            textLines: ["x"],
+            cases: [
+                VisuStructCase(name: "1", elements: [statement]),
+                VisuStructCase(name: "default", elements: [inner]),
+            ]
+        )
+        var doc = VisuStructDocumentEditing.newEmpty()
+        doc.elements = [statement, outer]
+        return doc
+    }
+
+    func testAncestorIsInnermostFallauswahl() {
+        let doc = document()
+        XCTAssertNil(VisuStructDocumentEditing.multiwayAncestorPath(for: nil, in: doc))
+        XCTAssertNil(VisuStructDocumentEditing.multiwayAncestorPath(for: [0], in: doc))
+        XCTAssertEqual(VisuStructDocumentEditing.multiwayAncestorPath(for: [1], in: doc), [1])
+        XCTAssertEqual(VisuStructDocumentEditing.multiwayAncestorPath(for: [1, 0, 0], in: doc), [1])
+        XCTAssertEqual(VisuStructDocumentEditing.multiwayAncestorPath(for: [1, 1, 0], in: doc), [1, 1, 0])
+        XCTAssertEqual(VisuStructDocumentEditing.multiwayAncestorPath(for: [1, 1, 0, 1, 0], in: doc), [1, 1, 0])
+    }
+
+    func testCaseIndex() {
+        XCTAssertNil(VisuStructDocumentEditing.caseIndex(of: [1], inMultiwayAt: [1]))
+        XCTAssertNil(VisuStructDocumentEditing.caseIndex(of: nil, inMultiwayAt: [1]))
+        XCTAssertEqual(VisuStructDocumentEditing.caseIndex(of: [1, 1, 0], inMultiwayAt: [1]), 1)
+    }
+}