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How to create a PRIVATE variable owned by the caller?
Posted: Tue Jan 10, 2023 2:19 pm
by Enrico Maria Giordano
This is a not working sample. Any ideas?
Code: Select all | Expand
#include "Fivewin.ch"
FUNCTION MAIN()
CREATEVAR( "TEST", "Hello" )
? M -> TEST // it does not exist here
RETURN NIL
STATIC FUNCTION CREATEVAR( cName, xValue )
// How to create a PRIVATE variable owned by the caller?
__MVPRIVATE( cName )
__MVPUT( cName, xValue )
? M -> TEST
RETURN NIL
Re: How to create a PRIVATE variable owned by the caller?
Posted: Tue Jan 10, 2023 3:54 pm
by hmpaquito
Hola,
Por definicion una variable PRIVATE tiene ambito en la funcion que la crea y en las funciones que son llamadas por la funcion que la crea.
En el caso que vd. expone es normal que no funcione.
Use en su caso PUBLIC
Salu2
Re: How to create a PRIVATE variable owned by the caller?
Posted: Tue Jan 10, 2023 4:17 pm
by Enrico Maria Giordano
No, it is possible. Please look at RESTORE FROM command.
Re: How to create a PRIVATE variable owned by the caller?
Posted: Tue Jan 10, 2023 6:42 pm
by hmpaquito
PRIVATE
Create and initialize private memory variables and arrays
Syntax
PRIVATE <identifier> [[:= <initializer>], ... ]
Arguments
<identifier> is the name of a private variable or array to create.
If the <identifier> is followed by square brackets ([ ]), an array is
created and assigned to the <identifier>. When the <identifier>
specification indicates an array, the syntax for specifying the number
of elements for each dimension can be array[<nElements>,
<nElements2>,...] or array[<nElements>][<nElements2>]... The maximum
number of elements per dimension is 4096. The maximum number of
dimensions is limited only by available memory.
<initializer> is the optional assignment of a value to a new private
variable. An array cannot be given values with an <initializer>. An
<initializer> for a private variable consists of the inline assignment
operator (:=) followed by any valid CA-Clipper expression including a
literal array. If no explicit <initializer> is specified, the variable
is initialized to NIL. In the case of an array, each element is
initialized to NIL.
You can create and, optionally, initialize a list of variables and
arrays with one PRIVATE statement if the definitions are separated by
commas.
Description
The PRIVATE statement creates variables and arrays visible within the
current and invoked procedures or user-defined functions. This class of
variable is said to have dynamic scope. Private variables exist for the
duration of the active procedure or until explicitly released with CLEAR
ALL, CLEAR MEMORY, or RELEASE. When a private variable or array is
created, existing and visible private and public variables of the same
name are hidden until the current procedure or user-defined function
terminates.
Re: How to create a PRIVATE variable owned by the caller?
Posted: Tue Jan 10, 2023 7:31 pm
by karinha
Re: How to create a PRIVATE variable owned by the caller?
Posted: Tue Jan 10, 2023 8:25 pm
by Enrico Maria Giordano
Please look at this sample:
Code: Select all | Expand
#include "Fivewin.ch"
FUNCTION MAIN()
CREATEMEM( "MYTEST.MEM", "TEST", "Hello" )
// ? M -> TEST // it does not exist here
__MVRESTORE( "MYTEST.MEM", .T. )
? M -> TEST // now it exists
RETURN NIL
STATIC FUNCTION CREATEMEM( cMem, cVar, xVal )
PRIVATE &cVar := xVal
SAVE TO ( cMem )
RETURN NIL
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 7:59 am
by hmpaquito
CreateMem() is not neccesary for private declaration on top main function:
Code: Select all | Expand
#include "Fivewin.ch"
FUNCTION MAIN()
// Note !!!!!! Try without that function call
/* CREATEMEM( "MYTEST.MEM", "TEST", "Hello" )
*/
// ? M -> TEST // it does not exist here
// Here implicit PUBLIC vars declaration
__MVRESTORE( "MYTEST.MEM", .T. )
? M -> TEST // now it exists
RETURN NIL
STATIC FUNCTION CREATEMEM( cMem, cVar, xVal )
PRIVATE &cVar := xVal
SAVE TO ( cMem )
RETURN NIL
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 8:38 am
by Enrico Maria Giordano
Code: Select all | Expand
Error description: (DOS Error 2) BASE/2005 Open error: MYTEST.MEM
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 11:10 am
by hmpaquito
Try it with your mytest.mem
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 11:21 am
by Enrico Maria Giordano
You completely missed the point.
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 11:41 am
by Antonio Linares
Dear Enrico,
Code: Select all | Expand
#include "Fivewin.ch"
FUNCTION MAIN()
CREATEVAR( "TEST", "Hello" )
? M -> TEST // it exists here
RETURN NIL
STATIC FUNCTION CREATEVAR( cName, xValue )
__MVPRIVATE( cName )
__MVPUT( cName, xValue )
__MVSETBASE()
? M -> TEST
RETURN NIL
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 11:49 am
by Enrico Maria Giordano
Great! Is there a similar function (__MVSETBASE()) available for xHarbour?
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 12:04 pm
by Antonio Linares
I am afraid no as xHarbour does not have the member stackstate in the struct hb_struSymbol
Maybe there is another way to do it, but I don't know it
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 12:06 pm
by Enrico Maria Giordano
Ok, no problem, thank you.
Re: How to create a PRIVATE variable owned by the caller?
Posted: Wed Jan 11, 2023 2:59 pm
by karinha
C:\HBBCC74\src\vm
03/04/2020 19:58 52.717 memvars.c
Regards, saludos.