for (; i < 4 && isValidHexPart(c = read()); i++) { unicodeSeq[i] = c;
for (; i < 4 && isValidHexPart(c = read()); i++) { unicodeSeq[i] = c;
for (; i < 4 && isValidHexPart(c = read()); i++) { unicodeSeq[i] = c;
for (; i < 4 && isValidHexPart(c = read()); i++) { unicodeSeq[i] = c;