question: public final void yypushStream ( java . io . Reader reader ) { zzStreams . push ( new ZzFlexStreamInfo ( zzReader , zzEndRead , zzStartRead , zzCurrentPos , zzMarkedPos , zzBuffer , zzAtEOF , yyline , yycolumn ) ) ; zzAtEOF = false ; zzBuffer = new char [ ZZ_BUFFERSIZE ] ; zzReader = reader ; zzEndRead = zzStartRead = 0 ; zzCurrentPos = zzMarkedPos = 0 ; yyline = yycolumn = 0 ; }
target:  Stores the current input stream on a stack, and reads from a new stream. Lexical state, line, char, and column counting remain untouched. The current input stream can be restored with yypopstream (usually in an <<EOF>> action).