From: "Christopher Nelson" <paradox AT gye DOT satnet DOT net>
To: <djgpp AT delorie DOT com>
Subject: Re: bison variable access
Date: Wed, 7 Jul 1999 20:17:03 -0600
Message-ID: <01bec8e7$f8200080$LocalHost@thendren>
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Reply-To: djgpp AT delorie DOT com

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>Now you're getting complicated.  The only way I can think of is to use some
"Variant" data
>type.  That would consist of a giant union of every possible datatype, and
a
>type-specifier.  Every time you wanted to make an assignment, or read a
value, you would
>have to go through a giant switch and choose the right union member.
>    I can think of a neat way of doing it in C++ using a class and some
overloaded
>operators.  It would still require the union, but now all you would have to
do is overload
>the '=' operator for every datatype, and just make the assignment into that
union member.



    i do, in fact, just have this particular class built.  the only members
that it does not support are double, long double, unsigned long long, and
long long.  this is because my implementation does not require them, so i
didn't want to waste the space.

    it is attatched, if you like.

    -={C}=-

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/************************************************************************=
****
  =DA=BF       =DA=BF
  =B3=C0=B4     =C3=D9=B3
  =B3         =B3
  =B3         =B3            =C2 =C2
  =B3         =B3 =DA=C4=C4=C4=BF =DA=C4=C4=BF =B3=DA=D9
  =B3   =DA=C4=BF   =B3 =C3=C4=C4=C4=B4 =B3    =C3=B4
  =C0=C4=BF =B3 =B3 =DA=C4=D9 =B3   =B3 =B3    =B3=C0=BF
    =C0=C4=D9 =C0=C4=D9   =C1   =C1 =C0=C4=C4=D9 =C1 =C1

         from the Wack Libraries
         (C)opyright 1999 Christopher Nelson
         (All Rights Reserved)

 =
*************************************************************************=
***/
#ifdef  __cplusplus
#ifndef __ANY_VALUE_CLASS__
#define __ANY_VALUE_CLASS__

#pragma interface "any.h"

#define SCHAR 	char
#define UCHAR 	unsigned char
#define SSHRT	short
#define USHRT	unsigned short
#define SINT  	int
#define UINT	unsigned int
#define SLONG	long
#define ULONG	unsigned long

#define FLOAT	float

#define STRING char *
#define SYMBOL void *

#define TYPE_BOOL 	0
#define TYPE_SCHAR	1
#define TYPE_UCHAR	2
#define TYPE_SSHRT	3
#define TYPE_USHRT	4
#define TYPE_SINT 	5
#define TYPE_UINT 	6
#define TYPE_SLONG	7
#define TYPE_ULONG	8

#define TYPE_FLOAT	9

#define TYPE_STRING	10
#define TYPE_SYMBOL	11

#define TYPE_USER		(1<<8)	//if the type is above this number it was
										//generated by the user.

typedef union tag_Value
  {
	bool	_bool;
	SCHAR	_schar;
	UCHAR	_uchar;
	SSHRT	_sshrt;
	USHRT	_ushrt;
	SINT	_sint;
	UINT	_uint;
	SLONG	_slong;
	ULONG	_ulong;
	FLOAT _float;

	STRING _string;
	SYMBOL _symbol;
} unionValue;

class Any
{
 public:
 UINT	    type;
 unionValue value;

 Any():type(0) { value._ulong=3D0; };
 ~Any() {};

 int friend operator=3D=3D(Any x, Any y)
     {
      if (x.type!=3Dy.type) return(0);
      switch(x.type)
        {
         case TYPE_BOOL:
              return(x.value._bool=3D=3Dy.value._bool);
         case TYPE_SCHAR:
              return(x.value._schar=3D=3Dy.value._schar);
         case TYPE_UCHAR:
              return(x.value._uchar=3D=3Dy.value._uchar);
         case TYPE_SINT:
              return(x.value._sint=3D=3Dy.value._sint);
         case TYPE_UINT:
              return(x.value._uint=3D=3Dy.value._uint);
         case TYPE_SSHRT:
              return(x.value._sshrt=3D=3Dy.value._sshrt);
         case TYPE_USHRT:
              return(x.value._ushrt=3D=3Dy.value._ushrt);
         case TYPE_SLONG:
              return(x.value._slong=3D=3Dy.value._slong);
         case TYPE_ULONG:
              return(x.value._ulong=3D=3Dy.value._ulong);
         case TYPE_FLOAT:
              return(x.value._float=3D=3Dy.value._float);
         case TYPE_STRING:
              return(strcmp(x.value._string, y.value._string));
         case TYPE_SYMBOL:
              return(0);  // <-- fixme!!
        }
     }

  void operator=3D(bool _value)    { type =3D TYPE_BOOL; value._bool =3D =
_value; 		};
  void operator=3D(SCHAR _value)	{ type =3D TYPE_SCHAR; value._schar =3D =
_value; 	   };
  void operator=3D(UCHAR _value)	{ type =3D TYPE_UCHAR; value._uchar =3D =
_value;		};
  void operator=3D(SINT  _value)	{ type =3D TYPE_SINT; value._sint =3D =
_value;     	};
  void operator=3D(UINT  _value)	{ type =3D TYPE_UINT; value._uint =3D =
_value;     	};
  void operator=3D(SSHRT _value)	{ type =3D TYPE_SSHRT; value._sshrt =3D =
_value;   	};
  void operator=3D(USHRT _value)	{ type =3D TYPE_USHRT; value._ushrt =3D =
_value;   	};
  void operator=3D(SLONG _value)	{ type =3D TYPE_SLONG; value._slong =3D =
_value;   	};
  void operator=3D(ULONG _value)	{ type =3D TYPE_ULONG; value._ulong =3D =
_value;   	};
  void operator=3D(FLOAT _value)	{ type =3D TYPE_FLOAT; value._float =3D =
_value;   	};
  void operator=3D(STRING _value)	{ type =3D TYPE_STRING; value._string =
=3D _value; 	};
  void operator=3D(SYMBOL _value)	{ type =3D TYPE_SYMBOL; value._symbol =
=3D _value; 	};
};


#endif //__ANY_VALUE_CLASS__
#endif //__cplusplus


// ****< Timestamp: Wed Jul  7 16:04:20 1999

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#pragma implementation "any.h"
#include "any.h"

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