Fix compilation for Swift <5.4

Author: Frizlab

Sources/CLTLogger.swift

@@ -404,7 +404,7 @@ private extension CLTLogger {
 	 Merge the logger’s metadata, the provider’s metadata and the given explicit metadata and return the new metadata.
 	 If the provider’s metadata and the explicit metadata are `nil`, returns `nil` to signify the current `flatMetadataCache` can be used. */
 	func mergedMetadata(with explicit: Logger.Metadata?) -> Logger.Metadata? {
-		var metadata = metadata
+		var metadata = self.metadata /* The self is required for Swift 5.3-. */
 		let provided = metadataProvider?.get() ?? [:]
 
 		guard !provided.isEmpty || !((explicit ?? [:]).isEmpty) else {

Sources/String+Utils.swift

@@ -38,12 +38,20 @@ internal extension String {
 
 				case .escapeScalars(_, let octothorpLevel?, _, true):
 					let octothorps = String(repeating: "#", count: Int(octothorpLevel))
-					return (octothorpLevel, octothorps + #"""#, #"""# + octothorps)
+//#if swift(>=5.4)
+//					return (octothorpLevel, octothorps + #"""#, #"""# + octothorps)
+//#else
+					return (octothorpLevel, octothorps + "\"", "\"" + octothorps)
+//#endif
 
 				case .escapeScalars(_, nil, _, let showQuotes):
 					/* We must determine the octothorp level. */
 					var level = UInt(0)
-					var (sepOpen, sepClose) = (#"""#, #"""#)
+//#if swift(>=5.4)
+//					var (sepOpen, sepClose) = (#"""#, #"""#)
+//#else
+					var (sepOpen, sepClose) = ("\"", "\"")
+//#endif
 					while str.contains(sepClose) {
 						level += 1
 						sepOpen = "#" + sepOpen
@@ -75,7 +83,11 @@ internal extension String {
 				if curSpecial.1 == octothorpLevel - 1 {
 					/* We have now reached the number of octothorp needed to build an actual “special char” (closing quote, backslash, etc.); we must escape it. */
 					specialCharState = nil
-					return #"\"# + octothorps + String(curSpecial.0) + octothorps
+//#if swift(>=5.4)
+//					return #"\"# + octothorps + String(curSpecial.0) + octothorps
+//#else
+					return "\\" + octothorps + String(curSpecial.0) + octothorps
+//#endif
 				}
 				specialCharState = (curSpecial.0, curSpecial.1 + 1)
 				return ""
@@ -112,7 +124,11 @@ internal extension String {
 						return prefix + ""
 					}
 					let escaped = scalar.escaped(asASCII: asASCII)
-					return prefix + (octothorpLevel == 0 ? escaped : escaped.replacingOccurrences(of: #"\"#, with: #"\"# + octothorps, options: .literal))
+//#if swift(>=5.4)
+//					return prefix + (octothorpLevel == 0 ? escaped : escaped.replacingOccurrences(of: #"\"#, with: #"\"# + octothorps, options: .literal))
+//#else
+					return prefix + (octothorpLevel == 0 ? escaped : escaped.replacingOccurrences(of: "\\", with: "\\" + octothorps, options: .literal))
+//#endif
 			}
 		}
 		let asciiJoined = ascii.joined(separator: "")
@@ -121,6 +137,10 @@ internal extension String {
 	}
 
 	private static let newLines = CharacterSet.newlines
-	private static let specialChars = CharacterSet(charactersIn: #""\"#)
-	
+//#if swift(>=5.4)
+//	private static let specialChars = CharacterSet(charactersIn: #""\"#)
+//#else
+	private static let specialChars = CharacterSet(charactersIn: "\"\\")
+//#endif
+
 }