Dim At

[Gösta H. Lovgren-2]

I just noticed something in the Array Passing code discussion (http:// www.powerbasic.com/support/pbforums/showthread.php?t=39196) and thought it worth a separate thread.

{Thinking out loud here}
In the code snippet below (part of Profile_Ordered_with_Variables.Inc - in Source Forum). str1 is Dimmed At (pointing to) an existing array that's part of a Type. In the cases shown here, the VarPtr(pfi.Bytes(1)) is actually 50 chars long per element (as defined by an Equate ), but the first Macro sends a 255 byte element array (address) to the Function. It should have been 'VarPtr(pfi.Procedures(1))
'
The Function works (I'm guessing) because the area pointed to is a pretty large chunk of (contiguous?) memory taken up by the UDT pfi (which has a lot of string arrays in it). And just lucky happenstance it didn't mess up any of the other pfi arrays.
'
I have seldom used Dim At myself and never really thought much about the concept before this. I understand it better now (I think & hope anyway). If anyone sees a flaw or misdirection in the rationale, I would certainly appreciate straightening it out (even if you have to rub it in. {grin}).

'Macro which calls "Profile_ProcessAnyArray_Procedures"                                  'VarPtr(pfi.Procedures(1)) Should be    
  ReDim srt1(1 To %Profile_Array_Elements) As String * %Profile_Procedure_Name_Length  At VarPtr(pfi.Bytes(1)) 
         Profile_ProcessAnyArray_Procedures(VarPtr(pfi.Procedures(1))) '255 byte elements
         Profile_ProcessAnyArray_Procedures(VarPtr(pfi.Macros(1)))     '      ""
'End Macro
'                
Function Profile_ProcessAnyArray_Procedures (pZ As Dword) As Long 'Sort the array point at by pz
 ReDim  Z(1 To %Profile_Array_Elements)  As String * %Profile_Procedure_Name_Length At pZ '255 bytes long   
   Array Sort z() 'effectively sorts the array pointed to by pz
End Function 
'
'Macro which calls "Profile_ProcessAnyArray_Variable"
  ReDim srt1(1 To %Profile_Array_Elements) As String * %Profile_Variable_Name_Length  At VarPtr(pfi.Bytes(1)) 
         Profile_ProcessAnyArray_Variable(VarPtr(pfi.Bytes(1)))        '50 byte elements
         Profile_ProcessAnyArray_Variable(VarPtr(pfi.Integers(1)))
' and so on for 10 more identically sized UDT arrays
'end macro                
Function Profile_ProcessAnyArray_Variable (pZ As Dword) As Long 
 ReDim  Z(1 To %Profile_Array_Elements)  As String * %Profile_Variable_Name_Length At pZ '50 bytes long    
   Array Sort z()'effectively sorts the array pointed to by pz
End Function 
'------------------/ProcessAnyArray'

==================================
"The difference between
'involvement' and 'commitment'
is like a ham-and-eggs breakfast:
the chicken was 'involved'
the pig was 'committed'."
unknown
==================================

[Michael Mattias]

The Function works (I'm guessing) because the area pointed to is a pretty large chunk of (contiguous?) memory

Actually, it works because both DIM AT and PB array data storage work as documented.

What you do with those capabilities is up to you.

The absolute array in its simplest form:

  H$ = "Hello, World" 
  REDIM cH(LEN(H$)-1) AS STRING * 1 AT STRPTR(H$) 
  FOR X = LBOUND (cH, 1) TO UBOUND (ch,1)
    PRINT    ch(X) 
  NEXT

That is, because the "DIM AT" capability exists, you can choose to consider "Hello, World" as either a single 12-character string or as a 12-element array of single characters.... whichever suits your application.

MCM
(I have loved absolute arrays ever since PB/DOS).

[Michael Mattias]

You've been around a while so you've probably seen the equivalent COBOL code...

 WORKING-STORAGE SECTION. 

  01  HELLO-WORLD    PIC X(12) 
  01  CH-ARRAY  REDEFINES HELLO-WORLD
       05 LETTER   PIC X(01) OCCURS 12 TIMES.

[Chris Holbrook]

You've been around a while...

Level 66?

[Michael Mattias]

'66' is the renames? Or is 66 the MF constants?

I think I only used renames once... where someone had created a 'library' copybook - inaccessible to us 'peon' contractors - which was put together really, really silly. Code ended up something like

   Copy sillylib. 
   66 (?)  USEFUL-GROUP-ITEM RENAMES  X THRU Y.

I used '88' (condition) a lot... except I had one client who forbade the use of '88' level datanames. (Go figger that one!)

'77' was always popular but for the most part I just put the disjoint W-S vars into a single '01' group item.

What's the other special one? 49, I think... what's used for ESQL working storage to create the "bind" variables used in

 
   EXEC SQL 
      SELECT   name INTO :WS-NAME from table where ...
   END-EXEC

I think that's all the 'specials'... 66,77,88 and 49. But not having written a line of COBOL since '01 I'm sure I've forgotten something by now...

[Chris Holbrook]

What's the other special one? 49

49 new to me. My last serious COBOL 1979.

[Gösta H. Lovgren-2]

Actually, it works because both DIM AT and PB array data storage work as documented.

Which tells me nothing, or at least anything I recognize. Presumably PB documentation is accurate (until demonstrated otherwise). As for being illuminating, in my case anyway, that's not always or even often the case. Which is a/the reason I started this thread.

That is, because the "DIM AT" capability exists, you can choose to consider "Hello, World" as either a single 12-character string or as a 12-element array of single characters.... whichever suits your application.
MCM
(I have loved absolute arrays ever since PB/DOS).

The advantage of which escapes me as well.

As for COBOL, I have (next to) zero knowledge or experience. COBOL examples help me little in understanding PB. A discussion of which is better suited in a separated thread.

My interest here is in what advantage/disadvatage does Dim At offer over a dynamic array. In the example above, the advantage of overlaying one array with another is obvious. Are there any others?

And the other point I wanted to make was the routine worked despite the fact I VarPtr'ed to the wrong area. (Note - Profile_Ordered_with_Variables.Inc in the Source Forum has been corrected). It seems to me that could lead to disasterous consequences (if the area pointed to was near the boundry of a data area segment and te overlay went beyond it and corrupted another program or something). It's a good example of Michael's proviso the compiler doesn't check for programmer stupidity/serendipity.

=========================================
"Life is pleasant.
Death is peaceful.
It's the transition that's troublesome."
Isaac Asimov
=========================================

[Michael Mattias]

My interest here is in what advantage/disadvatage does Dim At offer over a dynamic array. In the example above, the advantage of overlaying one array with another is obvious. Are there any others?

The advantage is, you can look at a block of memory different ways... it's kind of like a UNION on steroids. It's a source-code level tool to be used as desired.

In your specific case... it allows you to use the ARRAY functions (SORT/SCAN) on data which is otherwise not an array:

TYPE   FOO
      X (1:100) AS STRING * 2 
END TYPE

Since Foo.X() is NOT an array, you can't:

ARRAY SORT Foo.x()    <<<  compile time error 423 array variable expected

But if you create a genuine real array on top of that data...

  REDIM  X(1:100) AS STRING * 2  AT VARPTR (FOo.X(1))

...now you CAN sort it:

 ARRAY SORT X()

Complete explanation and examples under 'restrictions' of ARRAY SORT in help file.

Compilable example:

TYPE FOO
  X(1 TO 5) AS STRING * 2
END TYPE

FUNCTION PBMAIN () AS LONG
    
    LOCAL F AS FOO, S AS STRING, Z AS LONG
    F.X(1) = "ZZ"
    F.X(2) = "YY"
    F.X(3) = "XX"
    F.X(4) = "WW"
    F.X(5) = "VV"
    
    'ARRAY SORT F.X()  ' error 423 Array variable expected
    
    REDIM X(1 TO 5) AS STRING * 2 AT VARPTR (F.X(1))
    
    ARRAY SORT X()
    
    FOR Z = 1 TO 5
        S = S & F.X(Z) & "***"
    NEXT
    MSGBOX S
   
END FUNCTION

[John Petty]

It seems to me that could lead to disasterous consequences (if the area pointed to was near the boundry of a data area segment and te overlay went beyond it and corrupted another program or something).

Data segments disapeared with 16 bit, but you are correct, they can be very dangerous as it is up to the programmer to ensure the the amount of memory required for the array has already been allocated as the compiler does not check so easy to cause GPF's. If you think of it in terms of redfining a Union the the memory space must have already been allocated as some other data type such as a String or Array of another type and your absolute Array must not be defined to use more bytes than already allocated, nor can it be later redimmed larger. If redimmed smaller it will not erase or change the contents of the now unused bytes.
I use them all the time, my main use is if I want to do a lot of (exclusive) work on a large file of fixed length records which are defined with a UDT. I read the whole file into memory as a String with GET$, Dim an Array of the UDT's equal to the number of records AT the STRPTR, when finished just write the whole String back to the file in one go. Can give dramatic speed increases.
John

[Gösta H. Lovgren-2]

Okay, I think I'm getting a better picture now. In other terms, Dim AT sets aside a block of memory whose address doesn't change as long as the array is "in effect". The programmer can manipulate the contents of that memory block using other techniques such as assigning another array name to that block address and sorting it (as is done in M's ProcessAnyArray procedure.).

I think it also gives an insight into how Unions work although I've never used one.

Thanks John and all.

==================================
"Where are we going,
and why am I in this handbasket?"
Bumper Sticker
==================================

[Michael Mattias]

I think it also gives an insight into how Unions work although I've never used one.

Today's bonus... if you learn absolute arrays you just learned UNIONs... and vice-versa.

Yesterdays example using a UNION...

UNION Foo
  HELLO_WORLD           AS STRING * 12 
  CH (1 to 12)              AS STRING *  1
END UNION

FUNCTION PbMain() AS LONG 
   LOCAL  F AS Foo, S AS STRING , Z AS LONG
   F.Hello_World = "Hello, World" 
   FOR Z = 1 TO 12 
       S = S & CH (Z)
  NEXT
  MSGBOX F.HELLO_WORLD & $CRLF & S 
END FUNCTION

[John Petty]

Okay, I think I'm getting a better picture now. In other terms, Dim AT sets aside a block of memory whose address doesn't change as long as the array is "in effect".

Close but still not quite correct. DIM AT never sets aside the memory, it expects that memory to have already been set aside, and importantly that it will never change location as long as the DIM AT array is being used.
Taking Michaels earlier example and adding a line should explain

  H$ = "Hello, World" 
  REDIM cH(LEN(H$)-1) AS STRING * 1 AT STRPTR(H$)
  H$ = "New Hello, World" 'added line which will almost gaurantee a GPF later
  FOR X = LBOUND (cH, 1) TO UBOUND (ch,1)
    PRINT    ch(X) 
  NEXT

So the memory was allocated for the dynamic string H$ and the absolute array cH dimmed at its STRPTR, changing the contents of H$ will cause the string engine to invalidate the originally allocated memory and store the string most likely at a different location. The array cH does not track the change so will now be addressing invalid memory.
This is a big difference from a Union as with a Union all the different definitions of the memory space know if the location of the Union variable has moved.
John

[Gösta H. Lovgren-2]

Close but still not quite correct. DIM AT never sets aside the memory, it expects that memory to have already been set aside, and importantly that it will never change location as long as the DIM AT array is being used.

Okay John, I see the distinction and your example clarifies it even further for me.

Thanks all for helping me limp along the road.

=============================
A language is a more ancient
and inevitable
thing than any state.
Joseph Brodsky
=============================

[John Gleason]

Gösta, sometimes it helps to look at the data in a kind of table-like way, so here is a little demo you can watch change as you use it.

#PBFORMS Created
'--------------------------------------------------------------------------------
' The first line in this file is a PBForms metastatement.
' It should ALWAYS be the first line of the file. Other
' PBForms metastatements are placed at the beginning and
' ending of blocks of code that should be edited using
' PBForms only. Do not edit or delete these
' metastatements or PBForms will not be able to reread
' the file correctly. See the PBForms documentation for
' more information.
' Beginning blocks begin like this: #PBForms Begin ...
' Ending blocks begin like this:    #PBForms End ...
' Other PBForms metastatements such as:
'     #PBForms Declarations
' are used to tell PBForms where to insert additional
' code. Feel free to make changes anywhere else in the file.
'--------------------------------------------------------------------------------

#COMPILE EXE
#DIM ALL

'--------------------------------------------------------------------------------
'   ** Includes **
'--------------------------------------------------------------------------------
#PBFORMS Begin Includes
#IF NOT %DEF(%WINAPI)
    #INCLUDE "WIN32API.INC"
#ENDIF
#INCLUDE "PBForms.INC"
#PBFORMS End Includes
'--------------------------------------------------------------------------------

'--------------------------------------------------------------------------------
'   ** Constants **
'--------------------------------------------------------------------------------
#PBFORMS Begin Constants
%IDD_DIALOG1    = 101
%IDC_BUTTON1    = 1001
%IDC_BUTTON2    = 1002
%IDC_BUTTON3    = 1003
%IDC_BUTTON4    = 1004
%IDC_BUTTON5    = 1005
%IDC_BUTTON6    = 1006
%IDC_BUTTON7    = 1007
%IDC_BUTTON8    = 1008
%IDC_BUTTON9    = 1009
%IDC_LABEL1     = 1010
%IDC_LABEL2     = 1011
%IDC_LABEL3     = 1012
%IDC_LABEL4     = 1013
%IDC_LABEL5     = 1014
%IDC_LABEL6     = 1015
%IDC_LABEL7     = 1016
%IDC_LABEL8     = 1017
%IDC_LABEL9     = 1018
%IDC_BUTTON10   = 1019
%IDC_LABEL10    = 1020
#PBFORMS End Constants
'--------------------------------------------------------------------------------

'--------------------------------------------------------------------------------
'   ** Declarations **
'--------------------------------------------------------------------------------
DECLARE CALLBACK FUNCTION ShowDIALOG1Proc()
DECLARE FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
#PBFORMS Declarations
'--------------------------------------------------------------------------------

'--------------------------------------------------------------------------------
FUNCTION PBMAIN()
    ShowDIALOG1 %HWND_DESKTOP
END FUNCTION
'--------------------------------------------------------------------------------

'--------------------------------------------------------------------------------
'   ** CallBacks **
'--------------------------------------------------------------------------------
CALLBACK FUNCTION ShowDIALOG1Proc()
 STATIC memStr AS STRING, oSeq() AS LONG, oLseq() AS LONG, oQseq() AS LONG, oSseq() AS LONG
 STATIC b() AS BYTE, L() AS LONG, q() AS QUAD
 STATIC sorted, sortedL, sortedQ, sortedS, bAlloc, Lalloc, qAlloc, sAlloc AS LONG
 LOCAL  showStr AS STRING
 LOCAL ii AS LONG

    SELECT CASE CBMSG
        CASE %WM_COMMAND
            SELECT CASE CBCTL
                CASE %IDC_BUTTON1
                   EXIT FUNCTION
                CASE %IDC_BUTTON2
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       REDIM b(19) AS STATIC BYTE AT STRPTR(memStr)
                       FOR ii = 0 TO 19
                          showStr = showStr & MKBYT$(b(ii)) & " "
                       NEXT
                       showStr = showStr & "  ||" & RIGHT$(memStr, 20)
                       bAlloc = 1
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL2, " " & showStr
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL3, " " & showStr
                    END IF
                CASE %IDC_BUTTON3
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       IF bAlloc = 0 THEN
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          EXIT FUNCTION
                       END IF
                      IF sorted = 0 THEN
                         REDIM oSeq(19) AS STATIC LONG
                         FOR ii = 0 TO 19
                            oSeq(ii) = ii
                         NEXT
                         ARRAY SORT b(), TAGARRAY oSeq()
                         FOR ii = 0 TO 19
                            showStr = showStr & MKBYT$(b(ii)) & " "
                         NEXT
                         showStr = showStr & "  ||" & RIGHT$(memStr, 20)
                         sorted = 1
                      ELSE
                         ARRAY SORT oSeq(), TAGARRAY b()
                         FOR ii = 0 TO 19
                            showStr = showStr & MKBYT$(b(ii)) & " "
                         NEXT
                         showStr = showStr & "  ||" & RIGHT$(memStr, 20)
                         sorted = 0
                      END IF
                         GOSUB update
                    END IF
                CASE %IDC_BUTTON4
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       REDIM L(9) AS STATIC LONG AT STRPTR(memStr)
                       FOR ii = 0 TO 9
                          showStr = showStr & MKL$(L(ii)) & " "
                       NEXT
                       LAlloc = 1
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL4, " " & showStr
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL5, " " & showStr
                    END IF
                CASE %IDC_BUTTON5
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       IF LAlloc = 0 THEN
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          EXIT FUNCTION
                       END IF
                      IF sortedL = 0 THEN
                         REDIM oLseq(9) AS STATIC LONG
                         FOR ii = 0 TO 9
                            oLseq(ii) = ii
                         NEXT
                         ARRAY SORT L(), TAGARRAY oLseq()
                         FOR ii = 0 TO 9
                            showStr = showStr & MKL$(L(ii)) & " "
                         NEXT
                         sortedL = 1
                      ELSE
                         ARRAY SORT oLseq(), TAGARRAY L()
                         FOR ii = 0 TO 9
                            showStr = showStr & MKL$(L(ii)) & " "
                         NEXT
                         sortedL = 0
                      END IF
                         GOSUB update
                    END IF
                CASE %IDC_BUTTON6
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       REDIM q(4) AS STATIC QUAD AT STRPTR(memStr)
                       FOR ii = 0 TO 4
                          showStr = showStr & MKQ$(q(ii)) & " "
                       NEXT
                       qAlloc = 1
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL6, " " & showStr
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL7, " " & showStr
                    END IF
                CASE %IDC_BUTTON7
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       IF qAlloc = 0 THEN
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          EXIT FUNCTION
                       END IF
                      IF sortedq = 0 THEN
                         REDIM oQseq(4) AS STATIC LONG
                         FOR ii = 0 TO 4
                            oQseq(ii) = ii
                         NEXT
                         ARRAY SORT q(), TAGARRAY oQseq()
                         FOR ii = 0 TO 4
                            showStr = showStr & MKQ$(q(ii)) & " "
                         NEXT
                         sortedQ = 1
                      ELSE
                         ARRAY SORT oQseq(), TAGARRAY q()
                         FOR ii = 0 TO 4
                            showStr = showStr & MKQ$(q(ii)) & " "
                         NEXT
                         sortedQ = 0
                      END IF
                         GOSUB update
                    END IF
                CASE %IDC_BUTTON8
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       REDIM s(3) AS STATIC STRING * 10 AT STRPTR(memStr)
                       FOR ii = 0 TO 3
                          showStr = showStr & s(ii) & " "
                       NEXT
                       sAlloc = 1
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL8, " " & showStr
                       CONTROL SET TEXT CBHNDL, %IDC_LABEL9, " " & showStr
                    END IF
                CASE %IDC_BUTTON9
                    IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                       IF sAlloc = 0 THEN
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          EXIT FUNCTION
                       END IF
                      IF sorteds = 0 THEN
                         REDIM oSseq(3) AS STATIC LONG
                         FOR ii = 0 TO 3
                            oSseq(ii) = ii
                         NEXT
                         ARRAY SORT s(), TAGARRAY oSseq()
                         FOR ii = 0 TO 3
                            showStr = showStr & s(ii) & " "
                         NEXT
                         sorteds = 1
                      ELSE
                         ARRAY SORT oSseq(), TAGARRAY s()
                         FOR ii = 0 TO 3
                            showStr = showStr & s(ii) & " "
                         NEXT
                         sorteds = 0
                      END IF
                         GOSUB update
                    END IF

                CASE %IDC_BUTTON10
                   RESET oSeq(), oLseq(), oQseq(), oSseq(), b(), L(), q()
                   RESET sorted, sortedL, sortedQ, sortedS, bAlloc, Lalloc, qAlloc, sAlloc
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL2, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL3, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL4, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL5, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL6, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL7, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL8, ""
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL9, ""
                   memStr = "1234567890123456789012345678901234567890"       'make string mem block
                   CONTROL SET TEXT CBHNDL, %IDC_LABEL1, " " & memStr
            END SELECT

        CASE %WM_INITDIALOG
            memStr = "1234567890123456789012345678901234567890"       'make string mem block
            CONTROL SET TEXT CBHNDL, %IDC_LABEL1, " " & memStr
    END SELECT
    EXIT FUNCTION
    
   update:
    IF bAlloc THEN DIALOG POST CBHNDL, %WM_COMMAND, MAKLNG(%IDC_BUTTON2, %BN_CLICKED), 0
    IF LAlloc THEN DIALOG POST CBHNDL, %WM_COMMAND, MAKLNG(%IDC_BUTTON4, %BN_CLICKED), 0
    IF QAlloc THEN DIALOG POST CBHNDL, %WM_COMMAND, MAKLNG(%IDC_BUTTON6, %BN_CLICKED), 0
    IF sAlloc THEN DIALOG POST CBHNDL, %WM_COMMAND, MAKLNG(%IDC_BUTTON8, %BN_CLICKED), 0
    CONTROL SET TEXT CBHNDL, %IDC_LABEL1, " " & memStr
   RETURN
END FUNCTION
'--------------------------------------------------------------------------------

'--------------------------------------------------------------------------------
'   ** Dialogs **
'--------------------------------------------------------------------------------
FUNCTION ShowDIALOG1(BYVAL hParent AS DWORD) AS LONG
    LOCAL lRslt AS LONG
#PBFORMS Begin Dialog %IDD_DIALOG1->->
    LOCAL hDlg AS DWORD
    LOCAL hFont1 AS DWORD


    DIALOG NEW hParent, "DIM AT Demo", 47, 103, 584, 169, %WS_POPUP OR _
        %WS_BORDER OR %WS_DLGFRAME OR %WS_SYSMENU OR %WS_CLIPSIBLINGS OR _
        %WS_VISIBLE OR %DS_MODALFRAME OR %DS_3DLOOK OR %DS_NOFAILCREATE OR _
        %DS_SETFONT, %WS_EX_WINDOWEDGE OR %WS_EX_CONTROLPARENT OR %WS_EX_LEFT _
        OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON2, "DIM b(19) AS BYTE AT " + _
        "STRPTR(string)", 15, 25, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON3, "SORT or re-sort b() (BYTE)", 15, _
        40, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON4, "DIM L(9) AS LONG AT " + _
        "STRPTR(string)", 15, 55, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON5, "SORT or re-sort L() (LONG)", 15, _
        70, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON6, "DIM Q(4) AS QUAD AT " + _
        "STRPTR(string)", 15, 85, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON7, "SORT or re-sort Q() (QUAD)", 15, _
        100, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON8, "DIM s(3) AS STRING * 10 AT " + _
        "STRPTR(string)", 15, 115, 170, 15
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON9, "SORT or re-sort s() (STRING)", 15, _
        130, 170, 15
    CONTROL ADD LABEL, hDlg, %IDC_LABEL1, " ", 190, 10, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL1, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL2, " ", 190, 25, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL2, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL3, " ", 190, 40, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL3, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL4, " ", 190, 55, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL4, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL5, " ", 190, 70, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL5, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL6, " ", 190, 85, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL6, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL7, " ", 190, 100, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL7, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL8, " ", 190, 115, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL8, -1, %WHITE
    CONTROL ADD LABEL, hDlg, %IDC_LABEL9, " ", 190, 130, 380, 15, %WS_CHILD OR _
        %WS_VISIBLE OR %WS_BORDER OR %SS_LEFT OR %SS_CENTERIMAGE, %WS_EX_LEFT _
        OR %WS_EX_LTRREADING
    CONTROL SET COLOR hDlg, %IDC_LABEL9, -1, %WHITE
    CONTROL ADD BUTTON, hDlg, %IDC_BUTTON10, "Reset", 55, 150, 85, 15
    CONTROL ADD LABEL, hDlg, %IDC_LABEL10, "Current string in allocated memory", _
        15, 10, 170, 15, %WS_CHILD OR %WS_VISIBLE OR %WS_BORDER OR %SS_CENTER _
        OR %SS_CENTERIMAGE, %WS_EX_LEFT OR %WS_EX_LTRREADING

    hFont1 = PBFormsMakeFont("Courier New", 10, 400, %FALSE, %FALSE, %FALSE, %ANSI_CHARSET)

    CONTROL SEND hDlg, %IDC_LABEL1, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL2, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL3, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL4, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL5, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL6, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL7, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL8, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_LABEL9, %WM_SETFONT, hFont1, 0

#PBFORMS End Dialog

    DIALOG SHOW MODAL hDlg, CALL ShowDIALOG1Proc TO lRslt

    FUNCTION = lRslt
END FUNCTION
'--------------------------------------------------------------------------------

[Gösta H. Lovgren-2]

Gösta, sometimes it helps to look at the data in a kind of table-like way, so here is a little demo you can watch change as you use it.

Neat example John. I'll play around with it a little. Thanks.

=====================================================
"There are some experiences in life
which should not be demanded twice from any man,
and one of them is listening to the Brahms Requiem."
George Bernard Shaw (1856-1950)
=====================================================

[John Gleason]

puzzle solved

I don't know if it will lead to a deeper understanding of DIM AT, but while you're messing around with it, see if you can solve it too (fully sort it). It can be done as shown in the screenshot below. I took the screenshot 'cause I may not be able to repeat the solution.

[Gösta H. Lovgren-2]

I don't know if it will lead to a deeper understanding of DIM AT, but while you're messing around with it, see if you can solve it too (fully sort it). It can be done as shown in the screenshot below. I took the screenshot 'cause I may not be able to repeat the solution.

No solving of "John's" Cube Puzzle, but I did play around with the code John. Took me a little while (what doesn't anymore) but once I chgd the starting string to letters from numbers, much became clear. Changing the Button & Label Ids to more human intelligible names was a BIG help as well.

'http://www.powerbasic.com/support/pbforums/showthread.php?p=303453#post303453
'John Gleason
#PBForms Created
'--------------------------------------------------------------------------------
' The first line in this file is a PBForms metastatement.
' It should ALWAYS be the first line of the file. Other
' PBForms metastatements are placed at the beginning and
' ending of blocks of code that should be edited using
' PBForms only. Do not edit or delete these
' metastatements or PBForms will not be able to reread
' the file correctly. See the PBForms documentation for
' more information.
' Beginning blocks begin like this: #PBForms Begin ...
' Ending blocks begin like this:    #PBForms End ...
' Other PBForms metastatements such as:
'     #PBForms Declarations
' are used to tell PBForms where to insert additional
' code. Feel free to make changes anywhere else in the file.
'--------------------------------------------------------------------------------
#Compile Exe
#Dim All
'--------------------------------------------------------------------------------
'   ** Includes **
'--------------------------------------------------------------------------------
#PBForms Begin Includes
#If Not %Def(%WINAPI)
    #Include "WIN32API.INC"
#EndIf
#Include "PBForms.INC"
#PBForms End Includes
'--------------------------------------------------------------------------------
'--------------------------------------------------------------------------------
'   ** Constants **
'--------------------------------------------------------------------------------
#PBForms Begin Constants
%IDD_DIALOG1    = 101
%IDC_BUTTON1    = 1001
%Dim_Byte_Btn    = 1002
%Sort_Byte_Btn    = 1003
%Dim_Long_Btn    = 1004
%Sort_Long_Btn    = 1005
%Dim_Quad_Btn    = 1006
%Sort_Quad_Btn    = 1007
%Dim_Single_Btn    = 1008
%Sort_Single_Btn    = 1009
%IDC_LABEL1     = 1010
%Dim_Byte_Lbl     = 1011
%Sort_Byte_Lbl     = 1012
%Dim_Long_Lbl     = 1013
%Sort_Long_Lbl     = 1014
%Dim_Quad_Lbl     = 1015
%Sort_Quad_Lbl     = 1016
%Dim_String_Lbl     = 1017
%Sort_String_Lbl     = 1018
%Reset_Btn   = 1019
%IDC_LABEL10    = 1020
#PBForms End Constants
'--------------------------------------------------------------------------------
%John_Btn = 1021
'--------------------------------------------------------------------------------
'   ** Declarations **
'--------------------------------------------------------------------------------
Declare CallBack Function ShowDIALOG1Proc()
Declare Function ShowDIALOG1(ByVal hParent As Dword) As Long
#PBForms Declarations
'--------------------------------------------------------------------------------
'--------------------------------------------------------------------------------
Function PBMain()
    ShowDIALOG1 %HWND_DESKTOP
    'Call Resort_For_John
End Function
'--------------------------------------------------------------------------------
'--------------------------------------------------------------------------------
'   ** CallBacks **
'--------------------------------------------------------------------------------
CallBack Function ShowDIALOG1Proc()
 Static memStr As String, oSeq() As Long, oLseq() As Long, oQseq() As Long, oSseq() As Long
 Static b() As Byte, L() As Long, q() As Quad
 Static sorted, sortedL, sortedQ, sortedS, bAlloc, Lalloc, qAlloc, sAlloc As Long
 Local  showStr As String
 Local Start_String As String
 Local ii As Long
    Select Case CbMsg
        Case %WM_INITDIALOG
            Start_String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" 'try this
            memStr = "1234567890123456789012345678901234567890"       'make string mem block
            memstr = Start_String
            Control Set Text CbHndl, %IDC_LABEL1," " &  memStr
        Case %WM_COMMAND
            Select Case CbCtl
                Case %IDC_BUTTON1
                   Exit Function
                Case %Dim_Byte_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim b(19) As Static Byte At StrPtr(memStr)
                       For ii = 0 To 19
                          showStr = showStr & MkByt$(b(ii)) & " "
                       Next
                       showStr = showStr & "  ||" & Right$(memStr, 20)
                       bAlloc = 1
                       Control Set Text CbHndl, %Dim_Byte_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_Byte_Lbl, " " & showStr
                    End If
                Case %Sort_Byte_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If bAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sorted = 0 Then
                         ReDim oSeq(19) As Static Long
                         For ii = 0 To 19
                            oSeq(ii) = ii
                         Next
                         Array Sort b(), TagArray oSeq()
                         For ii = 0 To 19
                            showStr = showStr & MkByt$(b(ii)) & " "
                         Next
                         showStr = showStr & "  ||" & Right$(memStr, 20)
                         sorted = 1
                      Else
                         Array Sort oSeq(), TagArray b()
                         For ii = 0 To 19
                            showStr = showStr & MkByt$(b(ii)) & " "
                         Next
                         showStr = showStr & "  ||" & Right$(memStr, 20)
                         sorted = 0
                      End If
                         GoSub update
                    End If
                Case %Dim_Long_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim L(9) As Static Long At StrPtr(memStr)
                       For ii = 0 To 9
                          showStr = showStr & Mkl$(L(ii)) & " "
                       Next
                       LAlloc = 1
                       Control Set Text CbHndl, %Dim_Long_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_Long_Lbl, " " & showStr
                    End If
                Case %Sort_Long_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If LAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sortedL = 0 Then
                         ReDim oLseq(9) As Static Long
                         For ii = 0 To 9
                            oLseq(ii) = ii
                         Next
                         Array Sort L(), TagArray oLseq()
                         For ii = 0 To 9
                            showStr = showStr & Mkl$(L(ii)) & " "
                         Next
                         sortedL = 1
                      Else
                         Array Sort oLseq(), TagArray L()
                         For ii = 0 To 9
                            showStr = showStr & Mkl$(L(ii)) & " "
                         Next
                         sortedL = 0
                      End If
                         GoSub update
                    End If
                Case %Dim_Quad_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim q(4) As Static Quad At StrPtr(memStr)
                       For ii = 0 To 4
                          showStr = showStr & Mkq$(q(ii)) & " "
                       Next
                       qAlloc = 1
                       Control Set Text CbHndl, %Dim_Quad_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_Quad_Lbl, " " & showStr
                    End If
                Case %Sort_Quad_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If qAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sortedq = 0 Then
                         ReDim oQseq(4) As Static Long
                         For ii = 0 To 4
                            oQseq(ii) = ii
                         Next
                         Array Sort q(), TagArray oQseq()
                         For ii = 0 To 4
                            showStr = showStr & Mkq$(q(ii)) & " "
                         Next
                         sortedQ = 1
                      Else
                         Array Sort oQseq(), TagArray q()
                         For ii = 0 To 4
                            showStr = showStr & Mkq$(q(ii)) & " "
                         Next
                         sortedQ = 0
                      End If
                         GoSub update
                    End If
                Case %Dim_Single_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim s(3) As Static String * 10 At StrPtr(memStr)
                       For ii = 0 To 3
                          showStr = showStr & s(ii) & " "
                       Next
                       sAlloc = 1
                       Control Set Text CbHndl, %Dim_String_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_String_Lbl, " " & showStr
                    End If
                Case %Sort_Single_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If sAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sorteds = 0 Then
                         ReDim oSseq(3) As Static Long
                         For ii = 0 To 3
                            oSseq(ii) = ii
                         Next
                         Array Sort s(), TagArray oSseq()
                         For ii = 0 To 3
                            showStr = showStr & s(ii) & " "
                         Next
                         sorteds = 1
                      Else
                         Array Sort oSseq(), TagArray s()
                         For ii = 0 To 3
                            showStr = showStr & s(ii) & " "
                         Next
                         sorteds = 0
                      End If
                         GoSub update
                    End If
                Case %Reset_Btn
                   Reset oSeq(), oLseq(), oQseq(), oSseq(), b(), L(), q()
                   Reset sorted, sortedL, sortedQ, sortedS, bAlloc, Lalloc, qAlloc, sAlloc
                   Control Set Text CbHndl, %Dim_Byte_Lbl, ""
                   Control Set Text CbHndl, %Sort_Byte_Lbl, ""
                   Control Set Text CbHndl, %Dim_Long_Lbl, ""
                   Control Set Text CbHndl, %Sort_Long_Lbl, ""
                   Control Set Text CbHndl, %Dim_Quad_Lbl, ""
                   Control Set Text CbHndl, %Sort_Quad_Lbl, ""
                   Control Set Text CbHndl, %Dim_String_Lbl, ""
                   Control Set Text CbHndl, %Sort_String_Lbl, ""
                   memStr = "1234567890123456789012345678901234567890"       'make string mem block
                   Control Set Text CbHndl, %IDC_LABEL1, "" & memStr & "********"
                '
                Case %John_Btn   
                  Call Resort_for_John(CbHndl)
            End Select                 
 
    End Select
    Exit Function
 
   update:
    If bAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Byte_Btn, %BN_CLICKED), 0
    If LAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Long_Btn, %BN_CLICKED), 0
    If QAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Quad_Btn, %BN_CLICKED), 0
    If sAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Single_Btn, %BN_CLICKED), 0
    Control Set Text CbHndl, %IDC_LABEL1, " " & memStr
   Return
End Function
'--------------------------------------------------------------------------------
'--------------------------------------------------------------------------------
'   ** Dialogs **
'--------------------------------------------------------------------------------
Function ShowDIALOG1(ByVal hParent As Dword) As Long
    Local lRslt As Long
#PBForms Begin Dialog %IDD_DIALOG1->->
    Local hDlg As Dword
    Local hFont1 As Dword
 
    Dialog New hParent, "DIM AT Demo", 47, 103, 584, 169, %WS_POPUP Or _
        %WS_BORDER Or %WS_DLGFRAME Or %WS_SYSMENU Or %WS_CLIPSIBLINGS Or _
        %WS_VISIBLE Or %DS_MODALFRAME Or %DS_3DLOOK Or %DS_NOFAILCREATE Or _
        %DS_SETFONT, %WS_EX_WINDOWEDGE Or %WS_EX_CONTROLPARENT Or %WS_EX_LEFT _
        Or %WS_EX_LTRREADING Or %WS_EX_RIGHTSCROLLBAR, To hDlg
    Control Add Button, hDlg, %Dim_Byte_Btn, "DIM b(19) AS BYTE AT " + _
        "STRPTR(string)", 15, 25, 170, 15
    Control Add Button, hDlg, %Sort_Byte_Btn, "SORT or re-sort b() (BYTE)", 15, _
        40, 170, 15
    Control Add Button, hDlg, %Dim_Long_Btn, "DIM L(9) AS LONG AT " + _
        "STRPTR(string)", 15, 55, 170, 15
    Control Add Button, hDlg, %Sort_Long_Btn, "SORT or re-sort L() (LONG)", 15, _
        70, 170, 15
    Control Add Button, hDlg, %Dim_Quad_Btn, "DIM Q(4) AS QUAD AT " + _
        "STRPTR(string)", 15, 85, 170, 15
    Control Add Button, hDlg, %Sort_Quad_Btn, "SORT or re-sort Q() (QUAD)", 15, _
        100, 170, 15
    Control Add Button, hDlg, %Dim_Single_Btn, "DIM s(3) AS STRING * 10 AT " + _
        "STRPTR(string)", 15, 115, 170, 15
    Control Add Button, hDlg, %Sort_Single_Btn, "SORT or re-sort s() (STRING)", 15, _
        130, 170, 15
    Control Add Label, hDlg, %IDC_LABEL1, " ", 190, 10, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %IDC_LABEL1, -1, %White
    Control Add Label, hDlg, %Dim_Byte_Lbl, " ", 190, 25, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_Byte_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_Byte_Lbl, " ", 190, 40, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_Byte_Lbl, -1, %White
    Control Add Label, hDlg, %Dim_Long_Lbl, " ", 190, 55, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_Long_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_Long_Lbl, " ", 190, 70, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_Long_Lbl, -1, %White
    Control Add Label, hDlg, %Dim_Quad_Lbl, " ", 190, 85, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_Quad_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_Quad_Lbl, " ", 190, 100, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_Quad_Lbl, -1, %White
    Control Add Label, hDlg, %Dim_String_Lbl, " ", 190, 115, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_String_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_String_Lbl, " ", 190, 130, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_String_Lbl, -1, %White
    Control Add Button, hDlg, %Reset_Btn, "Reset", 55, 150, 85, 15
 
    Control Add Button, hDlg, %John_Btn, "Resort", 200, 150, 85, 15
 
    Control Add Label, hDlg, %IDC_LABEL10, "Current string in allocated memory", _
        15, 10, 170, 15, %WS_CHILD Or %WS_VISIBLE Or %WS_BORDER Or %SS_CENTER _
        Or %SS_CENTERIMAGE, %WS_EX_LEFT Or %WS_EX_LTRREADING
    hFont1 = PBFormsMakeFont("Courier New", 10, 400, %FALSE, %FALSE, %FALSE, %ANSI_CHARSET)
    Control Send hDlg, %IDC_LABEL1, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_Byte_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_Byte_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_Long_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_Long_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_Quad_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_Quad_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_String_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_String_Lbl, %WM_SETFONT, hFont1, 0
#PBForms End Dialog
    Dialog Show Modal hDlg, Call ShowDIALOG1Proc To lRslt
    Function = lRslt
End Function                                                                     
Sub Resort_For_John(hndl As Dword)
 Local t, srt() As String
 Local ctr, ln As Long
   Control Get Text Hndl, %IDC_LABEL1 To t$
    t$ = Trim$(t$)
    ln = Len(t$)
    ReDim srt$(1 To ln) 'create array of ln chars
    For ctr = 1 To ln                            
       srt$(ctr) = Mid$(t$, ctr, 1)
    Next ctr                       
    Array Sort srt$() 'sort them
    Reset t$
    For ctr = 1 To ln 'rearrange them
      t$ = t$ & srt$(ctr)
    Next ctr  
   Control Set Text Hndl, %IDC_LABEL1, t$ 'put it back
 
 
End Sub
'--------------------------------------------------------------------------------

==================================
I do not feel obliged to believe
the same God who has endowed us
with sense, reason, and intellect
intended us to forgo their use.
~ Galileo Galilei
==================================

[Gösta H. Lovgren-2]

John, Been fooling around some more with your code. I think I grasp the Dim At concept pretty good now. And a bonus is now I *think* I'm getting a glimmer behind the concept of packed strings though I'll have to explore that further I think.

(Note it helped below a lot when I changed the PBForms generated equates to human meaningful names.)

'http://www.powerbasic.com/support/pbforums/showthread.php?p=303453#post303453
'John Gleason
#PBForms Created
'--------------------------------------------------------------------------------
' The first line in this file is a PBForms metastatement.
' It should ALWAYS be the first line of the file. Other
' PBForms metastatements are placed at the beginning and
' ending of blocks of code that should be edited using
' PBForms only. Do not edit or delete these
' metastatements or PBForms will not be able to reread
' the file correctly. See the PBForms documentation for
' more information.
' Beginning blocks begin like this: #PBForms Begin ...
' Ending blocks begin like this:    #PBForms End ...
' Other PBForms metastatements such as:
'     #PBForms Declarations
' are used to tell PBForms where to insert additional
' code. Feel free to make changes anywhere else in the file.
'--------------------------------------------------------------------------------
 
#Compile Exe
#Dim All
 
'--------------------------------------------------------------------------------
'   ** Includes **
'--------------------------------------------------------------------------------
#PBForms Begin Includes
#If Not %Def(%WINAPI)
    #Include "WIN32API.INC"
#EndIf
#Include "PBForms.INC"
#PBForms End Includes
'--------------------------------------------------------------------------------
 
'--------------------------------------------------------------------------------
'   ** Constants **
'--------------------------------------------------------------------------------
#PBForms Begin Constants
%IDD_DIALOG1    = 101
%Dim_Byte_Btn    = 1002
%Sort_Byte_Btn    = 1003
%Dim_Long_Btn    = 1004
%Sort_Long_Btn    = 1005
%Dim_Quad_Btn    = 1006
%Sort_Quad_Btn    = 1007
%Dim_Single_Btn    = 1008
%Sort_Single_Btn    = 1009
%Original_String_lbl     = 1010
%Dim_Byte_Lbl     = 1011
%Sort_Byte_Lbl     = 1012
%Dim_Long_Lbl     = 1013
%Sort_Long_Lbl     = 1014
%Dim_Quad_Lbl     = 1015
%Sort_Quad_Lbl     = 1016
%Dim_String_Lbl     = 1017
%Sort_String_Lbl     = 1018
%Reset_Btn   = 1019
'%Original_String_lbl    = 1020
#PBForms End Constants
'--------------------------------------------------------------------------------
%Letters_Btn = 1021
%Mixed_Btn = 1022
'--------------------------------------------------------------------------------
'   ** Declarations **
'--------------------------------------------------------------------------------
Declare CallBack Function ShowDIALOG1Proc()
Declare Function ShowDIALOG1(ByVal hParent As Dword) As Long
#PBForms Declarations
'--------------------------------------------------------------------------------
 
'--------------------------------------------------------------------------------
Function PBMain()
    ShowDIALOG1 %HWND_DESKTOP
End Function
'--------------------------------------------------------------------------------
 
'--------------------------------------------------------------------------------
'   ** CallBacks **
'--------------------------------------------------------------------------------
CallBack Function ShowDIALOG1Proc()
 Static memStr As String, oSeq() As Long, oLseq() As Long, oQseq() As Long, oSseq() As Long
 Static b() As Byte, L() As Long, q() As Quad
 Static sorted, sortedL, sortedQ, sortedS, bAlloc, Lalloc, qAlloc, sAlloc As Long
 Local  showStr As String
 Static Mixed_String, num_String, Letter_String As String
 Local ii As Long
 
    Select Case CbMsg
        Case %WM_INITDIALOG
            Letter_String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" 'try this
            Num_String = "1234567890123456789012345678901234567890"       'make string mem block
            Mixed_String = "Now is the time for each man to come to the aid of his party."
'
            memstr = Num_String 
            'memstr = Letter_String 'use letters instead of numbers
            Control Set Text CbHndl, %Original_String_lbl," " &  memStr
        Case %WM_COMMAND
            Select Case CbCtl
                Case %Dim_Byte_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim b(19) As Static Byte At StrPtr(memStr)
                       For ii = 0 To 19
                          showStr = showStr & MkByt$(b(ii)) & "|"
                       Next
                       showStr = showStr & "  ||" & Right$(memStr, 20)
                       bAlloc = 1
                       Control Set Text CbHndl, %Dim_Byte_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_Byte_Lbl, " " & showStr
                    End If
                Case %Sort_Byte_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If bAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sorted = 0 Then
                         ReDim oSeq(19) As Static Long
                         For ii = 0 To 19
                            oSeq(ii) = ii
                         Next
                         Array Sort b(), TagArray oSeq()
                         For ii = 0 To 19
                            showStr = showStr & MkByt$(b(ii)) & "|"
                         Next
                         showStr = showStr & "  ||" & Right$(memStr, 20)
                         sorted = 1
                      Else
                         Array Sort oSeq(), TagArray b()
                         For ii = 0 To 19
                            showStr = showStr & MkByt$(b(ii)) & " "
                         Next
                         showStr = showStr & "  ||" & Right$(memStr, 20)
                         sorted = 0
                      End If
                         GoSub update
                    End If
                Case %Dim_Long_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim L(9) As Static Long At StrPtr(memStr)
                       For ii = 0 To 9
                          showStr = showStr & Mkl$(L(ii)) & "|"
                       Next
                       LAlloc = 1
                       Control Set Text CbHndl, %Dim_Long_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_Long_Lbl, " " & showStr
                    End If
                Case %Sort_Long_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If LAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sortedL = 0 Then
                         ReDim oLseq(9) As Static Long
                         For ii = 0 To 9
                            oLseq(ii) = ii
                         Next
                         Array Sort L(), TagArray oLseq()
                         For ii = 0 To 9
                            showStr = showStr & Mkl$(L(ii)) & "|"
                         Next
                         sortedL = 1
                      Else
                         Array Sort oLseq(), TagArray L()
                         For ii = 0 To 9
                            showStr = showStr & Mkl$(L(ii)) & "|"
                         Next
                         sortedL = 0
                      End If
                         GoSub update
                    End If
                Case %Dim_Quad_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim q(4) As Static Quad At StrPtr(memStr)
                       For ii = 0 To 4
                          showStr = showStr & Mkq$(q(ii)) & "|"
                       Next
                       qAlloc = 1
                       Control Set Text CbHndl, %Dim_Quad_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_Quad_Lbl, " " & showStr
                    End If
                Case %Sort_Quad_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If qAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sortedq = 0 Then
                         ReDim oQseq(4) As Static Long
                         For ii = 0 To 4
                            oQseq(ii) = ii
                         Next
                         Array Sort q(), TagArray oQseq()
                         For ii = 0 To 4
                            showStr = showStr & Mkq$(q(ii)) & "|"
                         Next
                         sortedQ = 1
                      Else
                         Array Sort oQseq(), TagArray q()
                         For ii = 0 To 4
                            showStr = showStr & Mkq$(q(ii)) & "|"
                         Next
                         sortedQ = 0
                      End If
                         GoSub update
                    End If
                Case %Dim_Single_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       ReDim s(3) As Static String * 10 At StrPtr(memStr)
                       For ii = 0 To 3
                          showStr = showStr & s(ii) & "|"
                       Next
                       sAlloc = 1
                       Control Set Text CbHndl, %Dim_String_Lbl, " " & showStr
                       Control Set Text CbHndl, %Sort_String_Lbl, " " & showStr
                    End If
                Case %Sort_Single_Btn
                    If CbCtlMsg = %BN_CLICKED Or CbCtlMsg = 1 Then
                       If sAlloc = 0 Then
                          ? "ERROR:  Array not allocated yet, so would likely GPF.", %MB_ICONERROR, "DIM AT Demo"
                          Exit Function
                       End If
                      If sorteds = 0 Then
                         ReDim oSseq(3) As Static Long
                         For ii = 0 To 3
                            oSseq(ii) = ii
                         Next
                         Array Sort s(), TagArray oSseq()
                         For ii = 0 To 3
                            showStr = showStr & s(ii) & "|"
                         Next
                         sorteds = 1
                      Else
                         Array Sort oSseq(), TagArray s()
                         For ii = 0 To 3
                            showStr = showStr & s(ii) & "|"
                         Next
                         sorteds = 0
                      End If
                         GoSub update
                    End If
 
                Case %Reset_Btn
                   Reset oSeq(), oLseq(), oQseq(), oSseq(), b(), L(), q()
                   Reset sorted, sortedL, sortedQ, sortedS, bAlloc, Lalloc, qAlloc, sAlloc
'                   Control Set Text CbHndl, %Dim_Byte_Lbl, ""
'                   Control Set Text CbHndl, %Sort_Byte_Lbl, ""
'                   Control Set Text CbHndl, %Dim_Long_Lbl, ""
'                   Control Set Text CbHndl, %Sort_Long_Lbl, ""
'                   Control Set Text CbHndl, %Dim_Quad_Lbl, ""
'                   Control Set Text CbHndl, %Sort_Quad_Lbl, ""
'                   Control Set Text CbHndl, %Dim_String_Lbl, ""
'                   Control Set Text CbHndl, %Sort_String_Lbl, ""
                   memStr = Num_String '"1234567890123456789012345678901234567890"       'make string mem block
                   Control Set Text CbHndl, %Original_String_lbl, "" & memStr & "********"
                '
                Case %Letters_Btn               
                    memstr = Letter_String 'use letters instead of numbers
                     Control Set Text CbHndl, %Original_String_lbl," " &  memStr
                '
                Case %Mixed_Btn
                    memstr = Mixed_String 'use Mixed instead of numbers
                     Control Set Text CbHndl, %Original_String_lbl," " &  memStr
                     
            End Select                 
           
 
    End Select
  Exit Function
    
   update: 'simulate Button Clicks
    If bAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Byte_Btn, %BN_CLICKED), 0
    If LAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Long_Btn, %BN_CLICKED), 0
    If QAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Quad_Btn, %BN_CLICKED), 0
    If sAlloc Then Dialog Post CbHndl, %WM_COMMAND, MakLng(%Dim_Single_Btn, %BN_CLICKED), 0
    Control Set Text CbHndl, %Original_String_lbl, " " & memStr
   Return
End Function
'--------------------------------------------------------------------------------
 
'--------------------------------------------------------------------------------
'   ** Dialogs **
'--------------------------------------------------------------------------------
Function ShowDIALOG1(ByVal hParent As Dword) As Long
    Local lRslt As Long
#PBForms Begin Dialog %IDD_DIALOG1->->
    Local hDlg As Dword
    Local hFont1 As Dword
 
 
    Dialog New hParent, "DIM AT Demo", 47, 103, 584, 169, %WS_POPUP Or _
        %WS_BORDER Or %WS_DLGFRAME Or %WS_SYSMENU Or %WS_CLIPSIBLINGS Or _
        %WS_VISIBLE Or %DS_MODALFRAME Or %DS_3DLOOK Or %DS_NOFAILCREATE Or _
        %DS_SETFONT, %WS_EX_WINDOWEDGE Or %WS_EX_CONTROLPARENT Or %WS_EX_LEFT _
        Or %WS_EX_LTRREADING Or %WS_EX_RIGHTSCROLLBAR, To hDlg
    Control Add Button, hDlg, %Dim_Byte_Btn, "DIM b(19) AS BYTE AT " + _
        "STRPTR(string)", 15, 25, 170, 15
    Control Add Button, hDlg, %Sort_Byte_Btn, "SORT or re-sort b() (BYTE)", 15, _
        40, 170, 15
    Control Add Button, hDlg, %Dim_Long_Btn, "DIM L(9) AS LONG AT " + _
        "STRPTR(string)", 15, 55, 170, 15
    Control Add Button, hDlg, %Sort_Long_Btn, "SORT or re-sort L() (LONG)", 15, _
        70, 170, 15
    Control Add Button, hDlg, %Dim_Quad_Btn, "DIM Q(4) AS QUAD AT " + _
        "STRPTR(string)", 15, 85, 170, 15
    Control Add Button, hDlg, %Sort_Quad_Btn, "SORT or re-sort Q() (QUAD)", 15, _
        100, 170, 15
    Control Add Button, hDlg, %Dim_Single_Btn, "DIM s(3) AS STRING * 10 AT " + _
        "STRPTR(string)", 15, 115, 170, 15
    Control Add Button, hDlg, %Sort_Single_Btn, "SORT or re-sort s() (STRING)", 15, _
        130, 170, 15
    Control Add Label, hDlg, %Original_String_lbl, " ", 190, 10, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Original_String_lbl, -1, %White
    Control Add Label, hDlg, %Dim_Byte_Lbl, " ", 190, 25, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_Byte_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_Byte_Lbl, " ", 190, 40, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_Byte_Lbl, -1, %White
    Control Add Label, hDlg, %Dim_Long_Lbl, " ", 190, 55, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_Long_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_Long_Lbl, " ", 190, 70, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_Long_Lbl, -1, %White
    Control Add Label, hDlg, %Dim_Quad_Lbl, " ", 190, 85, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_Quad_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_Quad_Lbl, " ", 190, 100, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_Quad_Lbl, -1, %White
    Control Add Label, hDlg, %Dim_String_Lbl, " ", 190, 115, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Dim_String_Lbl, -1, %White
    Control Add Label, hDlg, %Sort_String_Lbl, " ", 190, 130, 380, 15, %WS_CHILD Or _
        %WS_VISIBLE Or %WS_BORDER Or %SS_LEFT Or %SS_CENTERIMAGE, %WS_EX_LEFT _
        Or %WS_EX_LTRREADING
    Control Set Color hDlg, %Sort_String_Lbl, -1, %White
    Control Add Button, hDlg, %Reset_Btn, "Numbers String", 55, 150, 85, 15
    
    Control Add Button, hDlg, %Letters_Btn, "Letters String", 200, 150, 85, 15
    Control Add Button, hDlg, %Mixed_Btn, "Mixed String", 345, 150, 85, 15
    
    Control Add Label, hDlg, %Original_String_lbl, "Current string in allocated memory", _
        15, 10, 170, 15, %WS_CHILD Or %WS_VISIBLE Or %WS_BORDER Or %SS_CENTER _
        Or %SS_CENTERIMAGE, %WS_EX_LEFT Or %WS_EX_LTRREADING
 
    hFont1 = PBFormsMakeFont("Courier New", 10, 400, %FALSE, %FALSE, %FALSE, %ANSI_CHARSET)
 
    Control Send hDlg, %Original_String_lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_Byte_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_Byte_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_Long_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_Long_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_Quad_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_Quad_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Dim_String_Lbl, %WM_SETFONT, hFont1, 0
    Control Send hDlg, %Sort_String_Lbl, %WM_SETFONT, hFont1, 0
 
#PBForms End Dialog
 
    Dialog Show Modal hDlg, Call ShowDIALOG1Proc To lRslt
 
    Function = lRslt
End Function                                                                     
 
Sub Ltrs_not_Nbrs(hndl As Dword, ltr As String)
' Local t, srt() As String
' Local ctr, ln As Long
'   Control Get Text Hndl, %Original_String_lbl To t$
'    t$ = Trim$(t$)
'    ln = Len(t$)
'    ReDim srt$(1 To ln) 'create array of ln chars
'    For ctr = 1 To ln                            
'       srt$(ctr) = Mid$(t$, ctr, 1)
'    Next ctr                       
'    Array Sort srt$() 'sort them
'    Reset t$
'    For ctr = 1 To ln 'rearrange them
'      t$ = t$ & srt$(ctr)
'    Next ctr  
   Control Set Text Hndl, %Original_String_lbl, ltr$ 'put it back
    
    
End Sub
'--------------------------------------------------------------------------------

============================================================
"The instinct of nearly all societies is
to lock up anybody who is truly free.
First, society begins by trying to beat you up.
If this fails, they try to poison you.
If this fails too,
they finish by loading honors on your head."
Jean Cocteau (1889-1963)
============================================================