extended String to search for subsequence indexes

deltachat-ios/Extensions/Extensions.swift

@@ -9,63 +9,104 @@
 import UIKit
 
 extension String {
-  func containsCharacters() -> Bool {
-    return !trimmingCharacters(in: [" "]).isEmpty
-  }
+	func containsCharacters() -> Bool {
+		return !trimmingCharacters(in: [" "]).isEmpty
+	}
+
+	// O(n) - returns indexes of subsequences -> can be used to highlight subsequence within string
+	func contains(subSequence: String) -> [Int] {
+		if subSequence.count > self.count {
+			return []
+		}
+
+		let str = self.lowercased()
+		let sub = subSequence.lowercased()
+
+		var j = 0
+
+		var foundIndexes:[Int] = []
+
+		for (index, char) in str.enumerated() {
+			if j == sub.count {
+				break
+			}
+
+			if char == sub.subScript(j) {
+				foundIndexes.append(index)
+				j += 1
+
+			}
+		}
+		return foundIndexes.count == sub.count ? foundIndexes : []
+	}
+
+
+	func subScript(_ i: Int) -> Character {
+		return self[index(startIndex, offsetBy: i)]
+	}
+
+	func bold(indexes: [Int], fontSize: CGFloat?) -> NSAttributedString {
+		let attributedText = NSMutableAttributedString.init(string: self)
+
+		for index in indexes {
+			attributedText.addAttribute(.font, value: UIFont.boldSystemFont(ofSize: fontSize ?? 18), range: NSMakeRange(index, 1))
+		}
+		return attributedText
+	}
 }
 
 extension URL {
-  public var queryParameters: [String: String]? {
-    guard
-      let components = URLComponents(url: self, resolvingAgainstBaseURL: true),
-      let queryItems = components.queryItems else { return nil }
-    return queryItems.reduce(into: [String: String]()) { result, item in
-      result[item.name] = item.value
-    }
-  }
+	public var queryParameters: [String: String]? {
+		guard
+			let components = URLComponents(url: self, resolvingAgainstBaseURL: true),
+			let queryItems = components.queryItems else { return nil }
+		return queryItems.reduce(into: [String: String]()) { result, item in
+			result[item.name] = item.value
+		}
+	}
 }
 
 extension Dictionary {
-  func percentEscaped() -> String {
-    return map { key, value in
-      let escapedKey = "\(key)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
-      let escapedValue = "\(value)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
-      return escapedKey + "=" + escapedValue
-    }
-    .joined(separator: "&")
-  }
+	func percentEscaped() -> String {
+		return map { key, value in
+			let escapedKey = "\(key)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
+			let escapedValue = "\(value)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
+			return escapedKey + "=" + escapedValue
+			}
+			.joined(separator: "&")
+	}
 }
 
 extension CharacterSet {
-  static let urlQueryValueAllowed: CharacterSet = {
-    let generalDelimitersToEncode = ":#[]@" // does not include "?" or "/" due to RFC 3986 - Section 3.4
-    let subDelimitersToEncode = "!$&'()*+,;="
-
-    var allowed = CharacterSet.urlQueryAllowed
-    allowed.remove(charactersIn: "\(generalDelimitersToEncode)\(subDelimitersToEncode)")
-    return allowed
-  }()
+	static let urlQueryValueAllowed: CharacterSet = {
+		let generalDelimitersToEncode = ":#[]@" // does not include "?" or "/" due to RFC 3986 - Section 3.4
+		let subDelimitersToEncode = "!$&'()*+,;="
+
+		var allowed = CharacterSet.urlQueryAllowed
+		allowed.remove(charactersIn: "\(generalDelimitersToEncode)\(subDelimitersToEncode)")
+		return allowed
+	}()
 }
 
 extension URLSession {
-  func synchronousDataTask(request: URLRequest) -> (Data?, URLResponse?, Error?) {
-    var data: Data?
-    var response: URLResponse?
-    var error: Error?
+	func synchronousDataTask(request: URLRequest) -> (Data?, URLResponse?, Error?) {
+		var data: Data?
+		var response: URLResponse?
+		var error: Error?
 
-    let semaphore = DispatchSemaphore(value: 0)
+		let semaphore = DispatchSemaphore(value: 0)
 
-    let task = dataTask(with: request) {
-      data = $0
-      response = $1
-      error = $2
+		let task = dataTask(with: request) {
+			data = $0
+			response = $1
+			error = $2
 
-      semaphore.signal()
-    }
-    task.resume()
+			semaphore.signal()
+		}
+		task.resume()
 
-    _ = semaphore.wait(timeout: .distantFuture)
+		_ = semaphore.wait(timeout: .distantFuture)
 
-    return (data, response, error)
-  }
+		return (data, response, error)
+	}
 }