127 lines
3.9 KiB
C
127 lines
3.9 KiB
C
/*
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* $Id$
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*/
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/*
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* Harbour Project source code:
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* VAL() function
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*
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* Copyright 1999 Victor Szakats <info@szelvesz.hu>
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* www - http://www.harbour-project.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version, with one exception:
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*
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* The exception is that if you link the Harbour Runtime Library (HRL)
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* and/or the Harbour Virtual Machine (HVM) with other files to produce
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* an executable, this does not by itself cause the resulting executable
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* to be covered by the GNU General Public License. Your use of that
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* executable is in no way restricted on account of linking the HRL
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* and/or HVM code into it.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA (or visit
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* their web site at http://www.gnu.org/).
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*
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*/
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#include <math.h>
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#include "hbapi.h"
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#include "hbapiitm.h"
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#include "hbapierr.h"
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/* returns the numeric value of a character string representation of a number */
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double hb_strVal( const char * szText, ULONG ulLen )
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{
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double dValue = 0.0;
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ULONG ulPos;
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ULONG ulDecPos = 0;
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BOOL bNegative = FALSE;
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HB_TRACE(HB_TR_DEBUG, ("hb_strVal(%s, %d)", szText, ulLen));
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/* Look for sign */
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for( ulPos = 0; ulPos < ulLen; ulPos++ )
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{
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if( szText[ ulPos ] == '-' )
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{
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bNegative = TRUE;
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ulPos++;
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break;
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}
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else if( szText[ ulPos ] == '+' )
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{
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ulPos++;
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break;
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}
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else if( ! HB_ISSPACE( szText[ ulPos ] ) )
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break;
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}
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/* Build the number */
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for(; ulPos < ulLen; ulPos++ )
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{
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if( szText[ ulPos ] == '.' && ulDecPos == 0 )
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{
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ulDecPos++;
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}
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else if( szText[ ulPos ] >= '0' && szText[ ulPos ] <= '9' )
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{
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if( ulDecPos )
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dValue += ( ( double ) ( szText[ ulPos ] - '0' ) ) / pow( 10.0, ( double ) ulDecPos++ );
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else
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dValue = ( dValue * 10 ) + ( ( double ) ( szText[ ulPos ] - '0' ) );
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}
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else
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break;
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}
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return bNegative && dValue != 0.0 ? -dValue : dValue;
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}
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/* returns the numeric value of a character string representation of a number */
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HB_FUNC( VAL )
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{
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PHB_ITEM pText = hb_param( 1, HB_IT_STRING );
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if( pText )
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{
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char * szText = hb_itemGetCPtr( pText );
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int iWidth = ( int ) hb_itemGetCLen( pText );
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int iDec;
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double dValue = hb_strVal( szText, hb_itemGetCLen( pText ) );
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for( iDec = 0; iDec < iWidth && szText[ iDec ] != '.'; iDec++ );
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if( iDec >= iWidth - 1 )
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hb_retnlen( dValue, iWidth, 0 );
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else
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{
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/* NOTE: Kludge Warning! This condition:
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"|| ( iDec == 1 && szText[ 0 ] == '-' && dValue != 0.0 )"
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may not be the generic way to handle the width of this "-.1"
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string. I could not find a matching case which
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fails for the same reason, nor a better way to handle it.
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The problem is that in this case only, the width is
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calculated upon conditions which can only be discovered by
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parsing the string, but the parsing is made by a lower level
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generic function. [vszakats] */
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hb_retnlen( dValue, iDec + ( iDec == 0 || ( iDec == 1 && szText[ 0 ] == '-' && dValue != 0.0 ) ? 1 : 0 ), iWidth - iDec - 1 );
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}
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}
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else
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hb_errRT_BASE_SubstR( EG_ARG, 1098, NULL, "VAL" );
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}
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