A method may include receiving an extensible markup language schema definition (XSD) including a first element having a first simple datatype and a second element having a second simple datatype different from the first simple datatype. A grammar may be generated based on the XSD. The grammar may be associated with encoding and decoding an extensible markup language (XML) document based on the XSD to and from efficient XML interchange (EXI) streams. The grammar may be associated with the first simple datatype and with the second simple datatype.