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CHDataManagement/Extensions/String+Extensions.swift

@@ -12,6 +12,69 @@ extension String {
     var nonEmpty: String? {
         isEmpty ? nil : self
     }
+
+    var trimmed: String {
+        trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    func indented(by indentation: String) -> String {
+        components(separatedBy: "\n").joined(separator: "\n" + indentation)
+    }
+
+    var withoutEmptyLines: String {
+        components(separatedBy: "\n")
+            .filter { !$0.trimmed.isEmpty }
+            .joined(separator: "\n")
+    }
+
+    /**
+     Remove the part after the last occurence of the separator (including the separator itself).
+
+     The string is left unchanges, if it does not contain the separator.
+     */
+    func dropAfterLast(_ separator: String) -> String {
+        guard contains(separator) else {
+            return self
+        }
+        return components(separatedBy: separator).dropLast().joined(separator: separator)
+    }
+
+    func dropBeforeFirst(_ separator: String) -> String {
+        guard contains(separator) else {
+            return self
+        }
+        return components(separatedBy: separator).dropFirst().joined(separator: separator)
+    }
+
+    func lastComponentAfter(_ separator: String) -> String {
+        components(separatedBy: separator).last!
+    }
+
+    /**
+     Insert the new content before the last occurence of the specified separator.
+
+     If the separator does not appear in the string, then the new content is simply appended.
+     */
+    func insert(_ content: String, beforeLast separator: String) -> String {
+        let parts = components(separatedBy: separator)
+        guard parts.count > 1 else {
+            return self + content
+        }
+        return parts.dropLast().joined(separator: separator) + content + separator + parts.last!
+    }
+
+    /**
+     Remove everything behind the first separator.
+
+     Also removes the separator itself. If the separator is not contained in the string, then the full string is returned.
+     */
+    func dropAfterFirst<T>(_ separator: T) -> String where T: StringProtocol {
+        components(separatedBy: separator).first!
+    }
+
+    func between(_ start: String, and end: String) -> String {
+        dropBeforeFirst(start).dropAfterFirst(end)
+    }
 }
 
 extension String {
@@ -30,3 +93,26 @@ extension String {
         return (fileName: parts.dropLast().joined(separator: "."), fileExtension: parts.last)
     }
 }
+
+extension Substring {
+
+    func dropBeforeFirst(_ separator: String) -> String {
+        guard contains(separator) else {
+            return String(self)
+        }
+        return components(separatedBy: separator).dropFirst().joined(separator: separator)
+    }
+
+    func between(_ start: String, and end: String) -> String {
+        components(separatedBy: start).last!
+            .components(separatedBy: end).first!
+    }
+
+    func between(first: String, andLast last: String) -> String {
+        dropBeforeFirst(first).dropAfterLast(last)
+    }
+
+    func last(after: String) -> String {
+        components(separatedBy: after).last!
+    }
+}