nl_tokens: Read a variable length number our of delta and move the offset .
pl_tokens: function readLength ( ) { var byte = delta [ deltaOffset ++ ] ; var length = byte & 0x7f ; var shift = 7 ; while ( byte & 0x80 ) { byte = delta [ deltaOffset ++ ] ; length |= ( byte & 0x7f ) << shift ; shift += 7 ; } return <mask> ; }