             let c = utf8[index]
             index = utf8.index(after: index)
             switch c {
-            case 123: // {
-                return 125 // }
-            case 60: // <
-                return 62 // >
+            case asciiOpenCurlyBracket: // {
+                return asciiCloseCurlyBracket // }
+            case asciiOpenAngleBracket: // <
+                return asciiCloseAngleBracket // >
             default:
                 break
             }

            eof = true
            return nil
        }
        if utf8[index] == 91 { // [
            index = utf8.index(after: index)
            if let s = parseExtensionKey() {
                if index == utf8.endIndex || utf8[index] != 93 {
                    throw DecodingError.malformedText
                }
                // Skip ]

            throw DecodingError.malformedText
        }
        let c = utf8[index]
        if c != asciiSingleQuote && c != asciiDoubleQuote {
            throw DecodingError.malformedText
        }
        index = utf8.index(after: index)
