int decodeEscaped()

in src/org/apache/xerces/impl/xpath/regex/RegexParser.java [1091:1187]
94 lines of code
46 McCabe index (conditional complexity)

    int decodeEscaped() throws ParseException {
        if (this.read() != T_BACKSOLIDUS)  throw ex("parser.next.1", this.offset-1);
        int c = this.chardata;
        switch (c) {
          case 'e':  c = 0x1b;  break; // ESCAPE U+001B
          case 'f':  c = '\f';  break; // FORM FEED U+000C
          case 'n':  c = '\n';  break; // LINE FEED U+000A
          case 'r':  c = '\r';  break; // CRRIAGE RETURN U+000D
          case 't':  c = '\t';  break; // HORIZONTAL TABULATION U+0009
          //case 'v':  c = 0x0b;  break; // VERTICAL TABULATION U+000B
          case 'x':
            this.next();
            if (this.read() != T_CHAR)  throw ex("parser.descape.1", this.offset-1);
            if (this.chardata == '{') {
                int v1 = 0;
                int uv = 0;
                do {
                    this.next();
                    if (this.read() != T_CHAR)  throw ex("parser.descape.1", this.offset-1);
                    if ((v1 = hexChar(this.chardata)) < 0)
                        break;
                    if (uv > uv*16) throw ex("parser.descape.2", this.offset-1);
                    uv = uv*16+v1;
                } while (true);
                if (this.chardata != '}')  throw ex("parser.descape.3", this.offset-1);
                if (uv > Token.UTF16_MAX)  throw ex("parser.descape.4", this.offset-1);
                c = uv;
            } else {
                int v1 = 0;
                if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                    throw ex("parser.descape.1", this.offset-1);
                int uv = v1;
                this.next();
                if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                    throw ex("parser.descape.1", this.offset-1);
                uv = uv*16+v1;
                c = uv;
            }
            break;

          case 'u':
            int v1 = 0;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            int uv = v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            c = uv;
            break;

          case 'v':
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            if (uv > Token.UTF16_MAX)  throw ex("parser.descappe.4", this.offset-1);
            c = uv;
            break;
          case 'A':
          case 'Z':
          case 'z':
            throw ex("parser.descape.5", this.offset-2);
          default:
        }
        return c;
    }