Background​ In rpc/serialization systems, we often need to send namespace/path/filename/fieldName/packageName/moduleName/className/enumValue string between processes. Those strings are mostly ascii strings. In order to transfer between processes, we encode such strings using utf-8 encodings. Such encoding will take one byte for every char, which is not space efficient actually. If we take a deeper look, we will found that most chars are lowercase chars, ., $ and _, which can be expressed in a m...