/* * Copyright ? 2002 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * California 95054, U.S.A. All rights reserved.  Sun Microsystems, Inc. has * intellectual property rights relating to technology embodied in the product * that is described in this document. In particular, and without limitation, * these intellectual property rights may include one or more of the U.S. * patents listed at http://www.sun.com/patents and one or more additional * patents or pending patent applications in the U.S. and in other countries. * U.S. Government Rights - Commercial software. Government users are subject * to the Sun Microsystems, Inc. standard license agreement and applicable * provisions of the FAR and its supplements.  Use is subject to license terms. * Sun,  Sun Microsystems,  the Sun logo and  Java are trademarks or registered * trademarks of Sun Microsystems, Inc. in the U.S. and other countries.  This * product is covered and controlled by U.S. Export Control laws and may be * subject to the export or import laws in other countries.  Nuclear, missile, * chemical biological weapons or nuclear maritime end uses or end users, * whether direct or indirect, are strictly prohibited.  Export or reexport * to countries subject to U.S. embargo or to entities identified on U.S. * export exclusion lists, including, but not limited to, the denied persons * and specially designated nationals lists is strictly prohibited. */options {  USER_TOKEN_MANAGER = true;}PARSER_BEGIN(CalcInputParser)public class CalcInputParser {}PARSER_END(CalcInputParser)void Input() :	{	  double larg = 0.0;	  double rarg;	}{  (     [      larg=Number() 	{	  CalcGUI.print(larg);	}    ]    (      <ADD>      rarg=Number()	{	  larg = larg + rarg;	  CalcGUI.print(larg);	}    |      <SUB>      rarg=Number()	{	  larg = larg - rarg;	  CalcGUI.print(larg);	}    |      <MUL>      rarg=Number()	{	  larg = larg * rarg;	  CalcGUI.print(larg);	}    |      <DIV>      rarg=Number()	{	  larg = (rarg==0) ? Float.POSITIVE_INFINITY : (larg / rarg);	  CalcGUI.print(larg);	}    )*    <EQ: "=" >  )*}double Number() :	{	  Token t;	  String image = "";	  double value = 0.0;	  double decimalPlace = 1.0;	}{  (    t=<DIGIT>	{	  image += t.image;	  value = value*10 + Integer.parseInt(t.image);	  CalcGUI.print(image);	}  )+  [    <DOT>	{	  image += ".";	  CalcGUI.print(image);	}    (      t=<DIGIT>	{	  image += t.image;	  decimalPlace *= 0.1;	  value = value + Integer.parseInt(t.image)*decimalPlace;	  CalcGUI.print(image);	}    )+  ]	{	  return value;	}|  <DOT>	{	  image = "0.";	  CalcGUI.print(image);	}  (    t=<DIGIT>	{	  image += t.image;	  decimalPlace *= 0.1;	  value = value + Integer.parseInt(t.image)*decimalPlace;	  CalcGUI.print(image);	}  )+	{	  return value;	}}