[Gambas-user] Recursion does not work

[Demosthenes Koptsis]

Hi,

i use ubuntu 9.10 and Gambas 2.13

i create an anagram application port from phpAG
http://phpag.sourceforge.net/

i completed the same app with VB5 and now i make it also in Gmabas

To make anagrams i use recursion
i face up with a problem of recursion.

i call anag() function from
PUBLIC SUB Button1_Click()
....
 anag(0, iLen, sArray)            'Make anagrams
....
END


And the function is this

PRIVATE FUNCTION anag(iStart AS Integer, iLen AS Integer, sArray AS Array)
'vars are ByVal by default
'Port code from phpAG code
' / * FOR ($j = $start; $j < $len; + + $j)
'     {
'       IF ($j == $start || $array[$j] != $array[$start])
'       {
'         $tmp = $array[$j];
'         $array[$j] = $array[$start];
'         $array[$start] = $tmp;
'         anag($array, $start + 1, $len);
'       }
'     }
' * /

DIM j AS Integer
DIM tmp AS String
DIM word AS String

     IF iStart < iLen THEN
         j = iStart
         WHILE (j < iLen)

             IF (j = iStart OR sArray[j] <> sArray[iStart]) THEN
                 tmp = sArray[j]
                 sArray[j] = sArray[iStart]
                 sArray[iStart] = tmp
                 anag((iStart + 1), iLen, sArray) 'recursion does not work
properly
             END IF

         j = j + 1
         WEND

     ELSE
         word = implode(sArray)
         TextArea1.Text = TextArea1.Text & word & gb.NewLine
  'Vb5       PRINT #2, word 'write to anagram.tmp the result
  '
   END IF

END


PRIVATE FUNCTION implode(sArray AS Array) AS String
'This function makes a string from the elements of a string array
DIM i AS Integer
DIM word AS String

FOR i = 0 TO (sArray.Length - 1)
word = word & sArray[i]
NEXT

RETURN word
END

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

So if user enter the letters "abc" must have all the combinations as

abc
acb
cab
cba
bca
bac

The same code works for vb5 like this

Private Function anag(ByVal iStart As Integer, ByVal iLen As Integer, ByVal
sArray As Variant)
'Port code from phpAG

    If iStart < iLen Then
        j = iStart
        While (j < iLen)

            If j = iStart Or sArray(j) <> sArray(iStart) Then
                tmp = sArray(j)
                sArray(j) = sArray(iStart)
                sArray(iStart) = tmp
                Call anag((iStart + 1), iLen, sArray)
            End If

        j = j + 1
        Wend
    Else
        word = implode(sArray)
        Text2.Text = Text2.Text & word & vbNewLine
        Print #2, word 'write to anagram.tmp the result

  End If

End Function


in Gambas i get wrong results i get
abc
acb
cab
cba
abc
acb

This means recursion does not work properly.
In VB5 it was needed to pass values BYVAL i read that this is the defaut in
Gambas. But does not work.
Why?

i attach my program for whoever want to help.




-- 

Γεια χαρα σε όλους!!!

Regards,

Demosthenes Koptsis
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