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exp.hThis is the verbatim text of the exp.h include file./* $Id: exp.h,v 1.4 2000/06/20 04:30:18 dbryson Exp $
Xbase project source code
This file contains a header file for the EXP object, which is
used for expression processing.
Copyright (C) 1997 Startech, Gary A. Kunkel
email - xbase@startech.keller.tx.us
www - http://www.startech.keller.tx.us/xbase.html
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
V 1.0 10/10/97 - Initial release of software
V 1.5 1/2/97 - Added memo field support
V 1.6a 4/1/98 - Added expression support
V 1.6b 4/8/98 - Numeric index keys
V 1.7.1 5/25/98 - Expression support enhancements
*/
#ifndef __XB_EXP_H__
#define __XB_EXP_H__
#include <xdb/xbase.h>
#ifdef XB_EXPRESSIONS /* compile if expression logic on */
#define XB_EXPRESSION xbExpNode
#include <xdb/xtypes.h>
#include <xdb/xstack.h>
#undef ABS
#undef MIN
#undef MAX
class XBDLLEXPORT xbDbf;
struct xbFuncDtl {
const char * FuncName; /* function name */
xbShort ParmCnt; /* no of parms it needs */
char ReturnType; /* return type of function */
void (*ExpFuncPtr)(); /* pointer to function routine */
};
struct xbExpNode {
char * NodeText; /* expression text */
char Type; /* same as TokenType below */
xbShort Len; /* length of expression text */
xbShort InTree; /* this node in the tree? 1=yes */
xbExpNode * Node; /* pointer to parent */
xbExpNode * Sibling1; /* pointer to sibling 1 */
xbExpNode * Sibling2; /* pointer to sibling 2 */
xbExpNode * Sibling3; /* pointer to sibling 3 */
xbShort DataLen; /* length of data in result buffer */
xbShort ResultLen; /* length of result buffer */
// char * Result; /* result buffer - ptr to result */
xbString StringResult;
xbDouble DoubResult; /* Numeric Result */
xbShort IntResult; /* logical result */
xbDbf * dbf; /* pointer to datafile */
xbShort FieldNo; /* field no if DBF field */
char ExpressionType; /* used in head node C,N,L or D */
public:
xbExpNode() :
NodeText(0),
Type(0),
Len(0),
InTree(0),
Node(0),
Sibling1(0),
Sibling2(0),
Sibling3(0),
DataLen(0),
ResultLen(0),
DoubResult(0),
IntResult(0),
dbf(0),
FieldNo(-1),
ExpressionType(0)
{}
~xbExpNode(){
if( Sibling1 ) delete Sibling1;
if( Sibling2 ) delete Sibling2;
if( Sibling3 ) delete Sibling3;
}
};
/* Expression handler */
class XBDLLEXPORT xbExpn : public xbStack, public xbDate {
public:
xbShort ProcessExpression( xbExpNode *, xbShort );
xbExpNode * GetTree( void ) { return Tree; }
void SetTreeToNull( void ) { Tree = NULL; }
xbExpNode * GetFirstTreeNode( xbExpNode * );
xbExpn( void );
xbShort GetNextToken( const char *s, xbShort MaxLen);
/* expression methods */
xbDouble ABS( xbDouble );
xbLong ASC( const char * );
xbLong AT( const char *, const char * );
char * CDOW( const char * );
char * CHR( xbLong );
char * CMONTH( const char * );
char * DATE();
xbLong DAY( const char * );
xbLong DESCEND( const char * );
xbLong DOW( const char * );
char * DTOC( const char * );
char * DTOS( const char * );
xbDouble EXP( xbDouble );
xbLong INT( xbDouble );
xbLong ISALPHA( const char * );
xbLong ISLOWER( const char * );
xbLong ISUPPER( const char * );
char * LEFT( const char *, xbShort );
xbLong LEN( const char * );
xbDouble LOG( xbDouble );
char * LOWER( const char * );
char * LTRIM( const char * );
xbDouble MAX( xbDouble, xbDouble );
xbLong MONTH( const char * ); /* MONTH() */
xbDouble MIN( xbDouble, xbDouble );
char * RECNO( xbULong );
xbLong RECNO( xbDbf * );
char * REPLICATE( const char *, xbShort );
char * RIGHT( const char *, xbShort );
char * RTRIM( const char * );
char * SPACE( xbShort );
xbDouble SQRT( xbDouble );
char * STR( const char * );
char * STR( const char *, xbShort );
char * STR( const char *, xbShort, xbShort );
char * STR( xbDouble );
char * STR( xbDouble, xbShort );
char * STR(xbDouble, xbUShort length, xbShort numDecimals );
char * STRZERO( const char * );
char * STRZERO( const char *, xbShort );
char * STRZERO( const char *, xbShort, xbShort );
char * STRZERO( xbDouble );
char * STRZERO( xbDouble, xbShort );
char * STRZERO( xbDouble, xbShort, xbShort );
char * SUBSTR( const char *, xbShort, xbShort );
char * TRIM( const char * );
char * UPPER( const char * );
xbLong VAL( const char * );
xbLong YEAR( const char * );
void SetDefaultDateFormat(const xbString f){ DefaultDateFormat = f; }
xbString GetDefaultDateFormat() const { return DefaultDateFormat; }
xbShort ProcessExpression( const char *exp, xbDbf * d );
xbShort ParseExpression( const char *exp, xbDbf * d );
XB_EXPRESSION * GetExpressionHandle();
char GetExpressionResultType(XB_EXPRESSION * );
char * GetCharResult();
xbString & GetStringResult();
xbDouble GetDoubleResult();
xbLong GetIntResult();
xbShort ProcessExpression( xbExpNode * );
xbShort BuildExpressionTree( const char * Expression, xbShort MaxTokenLen,
xbDbf *d );
#ifdef XBASE_DEBUG
void DumpExpressionTree( xbExpNode * );
void DumpExpNode( xbExpNode * );
#endif
private:
xbFuncDtl *XbaseFuncList; /* pointer to list of Xbase functions */
// xbExpNode *NextFreeExpNode; /* pointer to chain of free nodes */
xbExpNode *Tree;
xbShort LogicalType; /* set to 1 for logical type nodes */
char TokenType; /* E - Expression, not in simplest form */
/* C - Constant */
/* N - Numeric Constant */
/* O - Operator */
/* F - Function */
/* D - Database Field */
/* s - character string result */
/* l - logical or short int result */
/* d - double result */
char PreviousType; /* used to see if "-" follows operator */
char * Op1; /* pointer to operand 1 */
char * Op2; /* pointer to operand 2 */
xbDouble Opd1; /* double result 1 */
xbDouble Opd2; /* double result 2 */
xbShort OpLen1; /* length of memory allocated to operand 1 */
xbShort OpLen2; /* length of memory allocated to operand 2 */
xbShort OpDataLen1; /* length of data in op1 */
xbShort OpDataLen2; /* length of data in op2 */
char OpType1; /* type of operand 1 */
char OpType2; /* type of operand 2 */
xbShort TokenLen; /* length of token */
static xbString DefaultDateFormat; /*default date format for DTOC func*/
enum { WorkBufMaxLen = 200 };
char WorkBuf[WorkBufMaxLen+1];
xbShort IsWhiteSpace( char );
char IsSeparator( char );
xbExpNode * LoadExpNode( const char * ENodeText, const char EType,
const xbShort ELen, const xbShort BufLen );
xbShort OperatorWeight( const char *Oper, xbShort len );
xbShort ReduceComplexExpression( const char * NextToken, xbShort Len,
xbExpNode * cn, xbDbf *d );
xbShort GetFunctionTokenLen( const char *s );
xbShort ReduceFunction( const char *NextToken, xbExpNode *cn, xbDbf *d );
xbExpNode * GetNextTreeNode( xbExpNode * );
xbShort ProcessOperator( xbShort );
xbShort ProcessFunction( char * );
xbShort ValidOperation( char *, char, char );
char GetOperandType( xbExpNode * );
xbShort AlphaOperation( char * );
xbShort NumericOperation( char * );
xbExpNode * GetExpNode( xbShort );
xbShort GetFuncInfo( const char *Function, xbShort Option );
xbDouble GetDoub( xbExpNode * );
xbLong GetInt( xbExpNode * );
};
#endif // XB_EXPRESSIONS
#endif // __XB_EXP_H__
Copyright © 2000-2002 Derry Bryson. All Rights Reserved.
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