Remove ErrorLevel enum since it is not required to be part of the public API

Author: Raymond McCrae

Sources/HTMLSAXParser/HTMLSAXParser+libxml2.swift

@@ -131,14 +131,14 @@ internal extension HTMLSAXParser {
     private func handleParseResult(_ parseResult: Int32, _ handlerContext: HTMLSAXParser.HandlerContext) throws {
         // htmlParseDocument returns zero for success, therefore if non-zero we need to check the last error.
         if parseResult != 0 {
-            guard let error = handlerContext.lastError(),
-                let errorLevel = ErrorLevel(rawValue: Int(error.pointee.level.rawValue)) else {
-                    // If no last error was found or the error level has invalid value then just return.
+            guard let error = handlerContext.lastError() else {
+                    // If no last error was found then just return.
                     return
             }
 
+            let errorLevel = error.pointee.level
             switch errorLevel {
-            case .fatal: // if fatal then throw a parsingFailure
+            case XML_ERR_FATAL: // if fatal then throw a parsingFailure
                 let message: String
                 if let messageCString = error.pointee.message {
                     message = String(cString: messageCString).trimmingCharacters(in: .whitespacesAndNewlines)
@@ -149,8 +149,8 @@ internal extension HTMLSAXParser {
 
                 let location = Location(line: Int(error.pointee.line), column: Int(error.pointee.int2))
 
-                throw Error.parsingFailure(level: errorLevel, location: location, message: message)
-            case .none, .warning, .error: // All other levels of error will be considered success
+                throw Error.parsingFailure(location: location, message: message)
+            default: // All other levels of error will be considered success
                 break
             }
         }

Sources/HTMLSAXParser/HTMLSAXParser.swift

@@ -98,19 +98,12 @@ open class HTMLSAXParser {
         case error(message: String)
     }
 
-    public enum ErrorLevel: Int {
-        case none = 0
-        case warning = 1
-        case error = 2
-        case fatal = 3
-    }
-
     public enum Error: Swift.Error {
         case unknown
         case unsupportedCharEncoding
         case stringEncodingConversion
         case emptyDocument
-        case parsingFailure(level: ErrorLevel, location: Location, message: String)
+        case parsingFailure(location: Location, message: String)
     }
 
     public typealias EventHandler = (HTMLSAXParseContext, Event) -> Void
@@ -134,7 +127,7 @@ open class HTMLSAXParser {
 
      - Parameter string: The string containing the HTML content.
      - Parameter handler: The event handler closure that will be called during parsing.
-     - Throws: `HTMLParser.Error` if an error occured during parsing.
+     - Throws: `HTMLParser.Error` if a fatal error occured during parsing.
      */
     open func parse(string: String, handler: @escaping EventHandler) throws {
         guard let uft8Data = string.data(using: .utf8) else {
@@ -159,7 +152,7 @@ open class HTMLSAXParser {
      - Parameter encoding: The character encoding to interpret the data. If no encoding
      is given then the parser will attempt to detect the encoding.
      - Parameter handler: The event handler closure that will be called during parsing.
-     - Throws: `HTMLParser.Error` if an error occured during parsing.
+     - Throws: `HTMLParser.Error` if a fatal error occured during parsing.
      */
     open func parse(data: Data, encoding: String.Encoding? = nil, handler: @escaping EventHandler) throws {
         let dataLength = data.count