128 lines
3.5 KiB
C
128 lines
3.5 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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* EMPTY() function
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*
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* Copyright 1999 {list of individual authors and e-mail addresses}
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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 "extend.h"
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#include "itemapi.h"
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/* $DOC$
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* $FUNCNAME$
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* EMPTY
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* $CATEGORY$
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*
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* $ONELINER$
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* Checks if the passed argument is empty.
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* $SYNTAX$
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* EMPTY( <xExp> ) --> <lIsEmpty>
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* $ARGUMENTS$
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* <xExp> is any valid expression.
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* $RETURNS$
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* A logical value. It is true (.T.) if the passed argument is empty
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* otherwise it is false (.F.).
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* $DESCRIPTION$
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* This function checks if an expression has empty value and returns a
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* logical indicating whether it the expression is empty or not.
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* $EXAMPLES$
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* ? Empty( "I'm not empty" )
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* $TESTS$
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* function Test()
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* ? Empty( 1 ) --> .f.
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* ? Empty( Date() ) --> .f.
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* ? Empty( .f. ) --> .t.
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* return nil
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* $STATUS$
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* R
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* $COMPLIANCE$
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* EMPTY() is fully CA-Clipper compliant.
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* $SEEALSO$
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* LEN
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* $END$
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*/
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HARBOUR HB_EMPTY( void )
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{
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PHB_ITEM pItem = hb_param( 1, IT_ANY );
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/* NOTE: Double safety to ensure that a parameter was really passed,
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compiler checks this, but a direct hb_vmDo() call
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may not do so. [vszel] */
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if( pItem )
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{
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switch( pItem->type & ~IT_BYREF )
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{
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case IT_ARRAY:
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hb_retl( hb_arrayLen( pItem ) == 0 );
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break;
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case IT_STRING:
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case IT_MEMO:
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hb_retl( hb_strEmpty( hb_itemGetCPtr( pItem ), hb_itemGetCLen( pItem ) ) );
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break;
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case IT_INTEGER:
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hb_retl( hb_itemGetNI( pItem ) == 0 );
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break;
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case IT_LONG:
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hb_retl( hb_itemGetNL( pItem ) == 0 );
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break;
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case IT_DOUBLE:
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hb_retl( hb_itemGetND( pItem ) == 0.0 );
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break;
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case IT_DATE:
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/* NOTE: This is correct ! Get the date as long value. */
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hb_retl( hb_itemGetNL( pItem ) == 0 );
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break;
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case IT_LOGICAL:
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hb_retl( ! hb_itemGetL( pItem ) );
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break;
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case IT_BLOCK:
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hb_retl( FALSE );
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break;
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default:
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hb_retl( TRUE );
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break;
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}
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}
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else
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hb_retl( TRUE );
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}
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