Implemented the "subtract(_: )" function for the String+Helpers extension in the library target.

2025-09-29 19:44:11 +02:00
parent 480cd657c9
commit 8a8576ef5f
2 changed files with 140 additions and 0 deletions
@@ -0,0 +1,43 @@
+// ===----------------------------------------------------------------------===
+//
+// This source file is part of the Hummingbird DocC Middleware open source project
+//
+// Copyright (c) 2025 Röck+Cöde VoF. and the Hummingbird DocC Middleware project authors
+// Licensed under the EUPL 1.2 or later.
+//
+// See LICENSE for license information
+// See CONTRIBUTORS for the list of Hummingbird DocC Middleware project authors
+//
+// ===----------------------------------------------------------------------===
+
+import RegexBuilder
+
+extension String {
+    
+    /// Subtracts a prefix from a string.
+    /// - Parameters:
+    ///   - prefix: A prefix to remove from a string.
+    /// - Returns: A new string with a prefix removed, if any.
+    func subtract(
+        _ prefix: String
+    ) -> String? {
+        let reference = Reference(String.self)
+        let pattern = Regex {
+            prefix
+            Optionally {
+                Capture(as: reference) {
+                    OneOrMore(.anyNonNewline)
+                } transform: { output in
+                    String(output)
+                }
+            }
+        }
+        
+        guard let matches = self.prefixMatch(of: pattern) else {
+            return nil
+        }
+        
+        return matches.output.1
+    }
+    
+}