Powerbasic and Lotus Notes (LotusScript) and StringArrays

[Kenneth KP Poulsen]

Hi all !

I am currently working on a project, where it would save a
LOT of time if we could use the Sort command on an array of strings
from LotusScript.

I have no trouble with the example supplied for VisualBasic, but
when trying the same in LotusScript, i get an Application Error in
Lotus Notes.

As far as I know, Visual Basic stores string-arrays as UNICODE format
(2 bytes pr. character), and the vbApi32.inc converts these strings to
ANSI format.

Lotus uses LMBCS (Lotus Multi-Byte Character Set) to represent their
strings, and (As far as i know) these are also 2-bytes characters.

I get the array from Notes to the PB-dll allrigt, but when conver-
ting the characters, somthing goes wrong, and I am not skilled
enough in PB to be able to tell, what it is.

When sorting an Integer-array, there are no problems

I hope, that someone out there can help me !


Cheers,

Kenneth

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[Peter P Stephensen]

Kenneth--

If you can't solve your problem the 'correct' way, then try to
use a temporary text-file: PB writes the sorted data to the
text-file and LotusScript opens the text-files and reads the data.
I don't think it will slow down the procedure that much.

Regards
Peter

P.S.
Hyggeligt at møde en dansker her. Det sker næsten aldrig!

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[Kenneth KP Poulsen]

Hi Peter !

I have thought about that possibility, and it may end up with, that
I have to use that one. I would like to check though, if there
were no chances to use the DLL and Sort function "standard" first.

(One declare-statement, and one call from my LotusScript - I don't think
that it gets any easier )

Cheers, Kenneth


PS: Ja, det er sjældent man ser andre danskere herude ! - hvis det er,
så kan du fange mig på [email protected]

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[Peter P Stephensen]

kenneth --

here are some links (that you properly allready know):
link 1
link 2
link 3

regards
peter

p.s. min mail er psp.dst.dk

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[Kenneth KP Poulsen]

Thanks Peter for the Links - I have read through them all, but I
tried the examples one more time (as they are, and with changes !),
but not succesfully ;-(

It is the question, if there is anything to do but use the
TextFile-approach.

After - yet another - study of the Lotus Design Help File under
C-functions and Calls, the following statements occured:

---

Array:

A 4-byte pointer to the array stored in the LotusScript
internal array format

---

Passing arrays as arguments:

Because LotusScript stores an array in a private format, you can
pass an array by reference to a C function only if the function
is specifically written for LotusScript. The following example
shows how to declare and implement a C function that takes a
LotusScript array of long values.

In LotusScript:
Declare Function LSArrayArg Lib "MYDLL" (ArrLng () As Long)_
As Long
Dim MyArr(0 to 5) As Long
Print LSArrayArg(MyArr)

In C:
long C_CALL_TYPE LSArrayArg(LSsValueArray *pLSArr)
{
long *pData=pLSArr->Data;
//pData points to first array element
return pData[0]+pData[1]; //Sum first 2 array elements
}

Or:

long C_CALL_TYPE LSArrayArg(long **pLSArr)
{
long *pData=*pLSArr;
//pData points to first array element
return pData[0]+pData[1]; //Sum first 2 array elements


---------

I do not have the skills to re-programme the VbApi32.inc file, so
that it can be used for LotusScript arrays too, and I got to admit,
that I am a bit confused as to where I start, and where I will end

Cheers, Kenneth

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[Peter P Stephensen]

Kenneth--

I have tried to translate the functions:
To translate the first example you need to know the LSsValueArray type.
It looks something like:

type LSsValueArray
    ...
    Data as dword
    ....
end type

Let's assume that the LSsValueArray-type is well-defined. Then the function should
look something like this:

function LSArrayArg(byval lp as dword) export as long
 
    local pLSArr as LSsValueArray ptr
    local pData as long ptr
 
    pLSArr = lp
    pData = @pLSArr.Data
 
    function = @pData[0] + @pData[1]
 
end function

The second example is more streight foreward. I would prefer it as you do not
need the LSsValueArray-type

function LSArrayArg(byval lp as dword) export as long
 
    local pdw as dword ptr
    local pData as long ptr
 
    pdw = lp
    pData = @pdw
 
    function = @pData[0] + @pData[1]
 
end function

As far as I know, the PB-array is a pointer to a pointer. You should therefore
try this (it will properly not work):

function LSArrayArg(LSArr() as long) export as long
 
    function = LSArr(0) + LSArr(1)
 
end function

Actually, I don't think you should try to do functions like this:

Declare Function LSArrayArg Lib "MYDLL" (ArrLng () As Long) As Long

It may be possible, but it implies that you have to have a very well understanding
of the functioning of a Lotus-array.

A much simpler approch is this:

Declare Function LSArrayArg Lib "MYDLL" (FirstElement as long, NumberOfElements as long) As Long

with the dll-function:

Function LSArrayArg (FirstElement as long, NumberOfElements as long) export As Long
 
    dim DataArray(NumberOfElements) as long at varptr(FirstElement)
 
    function = DataArray(0) + DataArray(0)
 
end function

Regards
Peter



[This message has been edited by Peter P Stephensen (edited November 04, 2000).]

[Kenneth KP Poulsen]

Hi Peter.

Thank you very much for your help !! - I finally figured it out..
(after spending nearly 30 hours this saturday and sunday).

It turns out, that there is a bug i the Lotus Notes IDE, so values
in an array manipulated by Powerbasic (or any other language, for
that matter) are NOT shown correctly when returning from the DLL.

It showed the first 33 entries of the array correct (aside from
entry number 4, that only showed half the entry - go figure ,
and all the remaining elements of the array as empty values !.

When trying to actually show elements from the array, everything
went OK, and all the values were present, and in "good shape"

To say, that PB is fast is an understatement !!! - it would be more
precise to say, that it "blowed the top off of Lotus Notes". I had
the following results, when timing (appr.) the ACTUAL sorting.
(And not including the DLL call, and the initialization of the
LotusScript Array):

(This on a PIII, 300mhz with 192Mb of ram)

Sorting an array with 4600 string-entries : appr. 0,085 sec.
Sorting an array with 460.000 string-entries: appr. 8,5 sec.
Sorting an array with 920.000 string-entries: appr. 17 sec. (!!)

(I stopped at 920.000 entries, because it took too long for Lotus
to "export" all the arrays to the DLL - appr. 3,5 minutes for
2000+ individual arrays, that were combined into one single PB-array)

Once again - Amazing !!!!!

Thank you very much for your help !

Kenneth

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