"AS ANY" ?

[Neil Hosgood]

I see in the PBDLL6 Help file you can pass a parameter to
a sub/function "AS ANY" but for the life of me I cant get it
working
Something like this is what I am trying to do:

Function DoSomething(TheData as ANY, DataLen as Long)

It Just doesnt like the "as any".

Anyone have any Ideas ?

------------------

[Scott Turchin]

i strongly suspect you will be using that same byte array i was using...

http://www.powerbasic.com/support/pb...ead.php?t=3902



------------------
scott

[Neil Hosgood]

Thanx Scott. Will have a look at that.

One thing I did notice is that the following will compile

function Dosomething(ANY, DataLen as Long) Long


hmmm.

------------------

[Eric Pearson]

Neil --

Isn't AS ANY part of the Help File description for DECLARE? Not FUNCTION.

If I'm not mistaken, AS ANY can only be used to DECLARE a parameter in an external module, such as a DLL. It can't be used in a FUNCTION definition.

Basically AS ANY means that a pointer to some type of (unspecified) data will be passed to the sub or function. It's useful, for example, when the Windows API specifies "a pointer to one of the following eight types of data must be passed to this function".

> the following will compile
>
> function Dosomething(ANY, DataLen as Long) Long

That may compile, but what can you do with it? There's no variable name for your program to use in the function.

If you want to accomplish the same thing as AS ANY, all you have to do is use AS DWORD or AS LONG. Then you can use VARPTR or STRPTR to obtain a pointer for any type of data, and pass it to your function. The hard part is figuring out what to do with it, once the function receives the pointer.

-- Eric

------------------
Perfect Sync Development Tools
Perfect Sync Web Site
Contact Us: mailto:[email protected][email protected]</A>



[This message has been edited by Eric Pearson (edited June 21, 2001).]

[Neil Hosgood]

Its a bit vague, help file doesnt state that "as any" can only be
used with external api's.
>Isn't AS ANY part of the Help File description for DECLARE? Not FUNCTION.
>If I'm not mistaken, AS ANY can only be used to DECLARE a parameter in an external module, such as a DLL. It can't be used in a FUNCTION definition.


> the following will compile
>
> function Dosomething(ANY, DataLen as Long) Long

>That may compile, but what can you do with it? There's no variable name for your program to use in the function.

Yep I know that (hence the hmmm.)


Will try the dword or long.

BTW. its a UDT of unkown type that I want to read and just
write to a file.

TA.
Neil.

------------------




[This message has been edited by Neil Hosgood (edited June 21, 2001).]

[Neil Hosgood]

Just about got it, but need a bit more help.
The following code works (at least for me) only
if:
1. All elements of the UDT have data
2. if any element of the UDT is not a string then only
elements upto and including that element are got by
peek$.

Any Ideas? Pleaseeeee

#COMPILE EXE

TYPE MyType 'just an example
FirstName AS STRING * 20
LastName AS STRING * 20
Active AS STRING * 1
age AS STRING * 3
OtherStuff AS STRING * 10
END TYPE

GLOBAL Current AS MyType

FUNCTION PutUDT (BYVAL lpData AS DWORD , VarLen AS LONG) AS LONG
LOCAL Buffer AS STRING

Buffer = SPACE$(VarLen)

POKE$ VARPTR(Buffer), PEEK$(VARPTR(lpData), Varlen)

MSGBOX Buffer,,"Almost any UDT"

END FUNCTION

FUNCTION PBMAIN() AS LONG
LOCAL dwp AS DWORD, DataLen AS LONG

Current.FirstName = "Joe"
Current.LastName = "bloggs"
Current.Active = "Y"
Current.age = "70"
Current.OtherStuff = "rogue"

DataLen = SIZEOF(Current)
dwp = VARPTR(Current)

X& = PutUDT(dwp,DataLen)

END FUNCTION


[This message has been edited by Neil Hosgood (edited June 22, 2001).]

[Steve Hutchesson]

Neil,

==========================================================
BTW. its a UDT of unkown type that I want to read and just 
write to a file.
==========================================================

If all you require is the address of a structure, you can probably
use a LONG or DWORD as addresses in 32 bit windows are 32 bit in
size. How you read a UDT of unknown type is another matter. I gather
you must have some method of reading the correct length so that you
can save it to file.

If you knew the layout of the UDT, you may be able to cast the
address as a pointer and access its members that way.

Regards,

[email protected]


------------------

[Neil Hosgood]

Steve,

We must have been posting at the same time ?
did you see my code, just above you reply ?

Thats where I am stuck

------------------

[Lance Edmonds]

Neil, the MSGBOX statement is probably "tricking" you... it truncates at the first embedded CHR$(0) in Buffer$ before displaying the message. Try testing the length of Buffer$ instead of displaying it's contents.


------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Michael Mattias]

If your UDT is truly unknown, that's one thing; but if your UDT is "one of a known number of possibilities", you can use a UNION.

MCM

[Neil Hosgood]

Lance,
Thanx for you reply. Just tried testing length of buffer by
adding the following code to PutUDT().

BuffLen& = LEN(Buffer)
MSGBOX "Buffer Length = " & STR$(BuffLen&),,"Data in Buffer Should Be " & STR$(VarLen)

All hell broke loose and GPF's were abundant
Funny thing is, I comment out the MSGBOX line and all is well.

All I am trying to do is pass any UDT or STRING to a function
and write it to a binary file. The function that reads it from
the file just returns a string of what ever length is requested
by the caller, then its upto the caller to LSET the data into a type .

PS. Any comment on my Original question "As ANY" ?
------------------


[This message has been edited by Neil Hosgood (edited June 22, 2001).]

[Neil Hosgood]

Michael, the UDT is unkown, consider the PutUDT function
as something that wrote ANY UDT to a randon access file
(of course I would pass filehandle and index handle and key)
The code I have so far works with UDT's that are all strings
but seems to be tempramental

------------------

[Semen Matusovski]

Typically, "unknown" UDT includes, as minimum, one first additional field, let's say VersId, which allows to understand type (and length) of UDT.
Good samples - file formats (BMP, ICO and so on - http://www.wotsit.org )

------------------
E-MAIL: [email protected]

[Neil Hosgood]

Kewl site Semen

However I don't want this function to care what data type
is being sent to it. The function gets sent the length of
the data and a pointer, all it has to do is grab n bytes from
the location provided and write them to disk (in the real app
it compresses them before writing)

Why is it so hard in PB ?
In 1992 using VB1 with a cool DB package calleg Agility/VB it
took a one call to throw ANY data into a file (including
images, sound and UDT's)

Unfortunatly the Agility People have succumed to the MS Machine
and havnt re-written their package as a 32bit dll

Thats about enough bleats from me.
Have fun.

------------------

[Mike Burns]

Neil

Buffer is declared as a dynamic string. Shouldn't you be
using STRPTR instead of VARPTR to get the address for the Poke$?

Mike


------------------

[Neil Hosgood]

Mike.
Will give ite a go.... Nope, even worse

>Buffer is declared as a dynamic string. Shouldn't you be
>using STRPTR instead of VARPTR to get the address for the Poke$?

Have you compiled my source ?
It seems to work if all elements are strings and all have data,
even if the data id just a space.

N.


you will have to excuse my typing, it's 1:40am


------------------


[This message has been edited by Neil Hosgood (edited June 22, 2001).]

[Aldo Cavini]

Neil,

may be I didn't understand the problem. If the matter is to read ANY data at a given address for a given length, it is enough to:

FUNCTION ReadData( AddressData as DWORD, LengthData as DWORD ) AS LONG

LOCAL StringData AS STRING

  StringData = PEEK$( AddressData, LengthData )
  ........

END FUNCTION

FUNCTION PBMAIN AS LONG

LOCAL AnyUdt AS AnyUdtType

  ReadData VARPTR( AnyUdt ), SIZEOF( AnyUdt )

END FUNCTION

------------------

[This message has been edited by Aldo Cavini (edited June 22, 2001).]

[Scott Turchin]

So would this apply to my ReadEventLog as well? (See previous post)


???

------------------
Scott

[Neil Hosgood]

Aldo,

Thanx for your input, Just tried your idea and got any empty
string
what am I doing wrong ?

------------------

[Mike Burns]

Neil

This works

Poke$ StrPtr(Buffer), Peek$(lpData, Varlen)

You dont want the address of lpdata since you passed the address
in lpdata.

Aldo's example is functionally the same. Did you setup the udt in
his example?

Mike


------------------


[This message has been edited by Mike Burns (edited June 22, 2001).]