gambas-source-code/main/lib/eval/CExpression.c
Benoît Minisini 0bc1701225 [WIKI CGI SCRIPT]
* NEW: New look for version specific documentation.

[INTERPRETER]
* NEW: Assign() has been removed, and replaced by Eval() with an expression 
  beginning with the LET keyword.
* NEW: New routines to read a value stored at a memory address: BoolPtr(),
  BytePtr(), ShortPtr(), IntPtr(), LongPtr(), SinglePtr(), FloatPtr() and
  PointerPtr().

[COMPILER]
* NEW: The LET keyword can be used to write an assignment expression. Of
  course it is optional.

[GB.EVAL]
* NEW: The LET keyword can be used to evaluate an assignment.
* NEW: The Expression.Compile() method does not take any argument anymore.

git-svn-id: svn://localhost/gambas/trunk@3041 867c0c6c-44f3-4631-809d-bfa615b0a4ec
2010-07-14 16:33:29 +00:00

147 lines
3.1 KiB
C

/***************************************************************************
CExpression.c
(c) 2000-2009 Benoît Minisini <gambas@users.sourceforge.net>
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, 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.
***************************************************************************/
#define __CEXPRESSION_C
#include "gb_common.h"
#include "gambas.h"
#include "eval.h"
#include "main.h"
#include "CExpression.h"
/*#define DEBUG*/
static CEXPRESSION *_current;
BEGIN_METHOD_VOID(CEXPRESSION_new)
THIS->compiled = FALSE;
CLEAR(&THIS->expr);
END_METHOD
BEGIN_METHOD_VOID(CEXPRESSION_free)
EVAL_clear(&THIS->expr);
GB.FreeString(&THIS->text);
GB.FreeString(&THIS->expr.source);
GB.Unref((void **)&THIS->env);
END_METHOD
BEGIN_PROPERTY(CEXPRESSION_text)
if (READ_PROPERTY)
GB.ReturnString(THIS->text);
else
{
GB.StoreString(PROP(GB_STRING), &THIS->text);
GB.FreeString(&THIS->expr.source);
THIS->expr.source = GB.NewString(THIS->text, VPROP(GB_STRING).len);
THIS->expr.len = VPROP(GB_STRING).len;
THIS->compiled = FALSE;
}
END_PROPERTY
BEGIN_PROPERTY(CEXPRESSION_environment)
if (READ_PROPERTY)
GB.ReturnObject(THIS->env);
else
GB.StoreObject(PROP(GB_OBJECT), &THIS->env);
END_PROPERTY
static void prepare(CEXPRESSION *_object)
{
if (!THIS->compiled && (THIS->expr.len > 0))
{
if (!EVAL_compile(&THIS->expr, FALSE))
THIS->compiled = TRUE;
}
}
BEGIN_METHOD_VOID(CEXPRESSION_prepare)
prepare(THIS);
END_METHOD
static bool get_variable(const char *sym, int len, GB_VARIANT *value)
{
if (_current->env)
if (!GB.Collection.Get(_current->env, sym, len, value))
return FALSE;
value->type = GB_T_NULL;
return TRUE;
}
static void execute(CEXPRESSION *_object)
{
if (!THIS->compiled)
prepare(THIS);
if (!THIS->compiled)
{
GB.ReturnNull();
return;
}
_current = THIS;
EVAL_expression(&THIS->expr, (EVAL_FUNCTION)get_variable);
}
BEGIN_PROPERTY(CEXPRESSION_value)
execute(THIS);
END_PROPERTY
GB_DESC CExpressionDesc[] =
{
GB_DECLARE("Expression", sizeof(CEXPRESSION)),
//GB_STATIC_METHOD("_init", NULL, CEXPRESSION_init, NULL),
//GB_STATIC_METHOD("_exit", NULL, CEXPRESSION_exit, NULL),
GB_METHOD("_new", NULL, CEXPRESSION_new, NULL),
GB_METHOD("_free", NULL, CEXPRESSION_free, NULL),
GB_PROPERTY("Text", "s", CEXPRESSION_text),
GB_PROPERTY("Environment", "Collection;", CEXPRESSION_environment),
GB_METHOD("Compile", NULL, CEXPRESSION_prepare, NULL),
GB_PROPERTY_READ("Value", "v", CEXPRESSION_value),
GB_END_DECLARE
};