[libreoffice-users] Basic : How to write a CopyValue() recursive function ?

Hi,

I'm traying to build a recursive CopyValue(aVariant) function. The idea 
is a simple copy for scalar values, a recursive Items copy for array 
(max 5 dimensions arrays), and a call to Clone() method for (pseudo) 
objects. The function can't copy structures, I will use (pseudo) objects 
Clone() method...

But my code (Cf. "TEST COPY VALUE CODE" below) failed at CopyArray in 
Select Case 2 at line :

result(i1 - Bounds(1,1), i2 - Bounds(2,1)) = CopyValue(value)

The error message (in french) is :
"L'erreur #91 (Variable d'objet non définie) s'est produite à la ligne 
90 dans _DataUtil"

The error is triggered with the recursive function call at 
CopyValue(value). It look's like reentrance is not supported by the 
function... I'm using LibreOffice 5.2.7.2. (x32) with Linux Debian. I 
tested also with LIbreOffice 5.4.2.2 (x64) with Windows.

So to test recursive call I tried with a recursive sample function, 
CalculateFactorial(Number).  And it's work fine. The sample is :

Sub TestFactorial
  Msgbox CalculateFactorial(  42 )    ' Displays 1,40500611775288E+51
  Msgbox CalculateFactorial( -42 )    ' Displays "Invalid number for 
factorial!"
  Msgbox CalculateFactorial( 3.14 )   ' Displays "Invalid number for 
factorial!"
End Sub

Function CalculateFactorial( Number )
  If Number < 0 Or Number <> Int( Number ) Then
    CalculateFactorial = "Invalid number for factorial!"
  ElseIf Number = 0 Then
    CalculateFactorial = 1
  Else
    ' This is the recursive call:
    CalculateFactorial = Number * CalculateFactorial( Number - 1 )
  Endif
End Function

I'm wondering If my problem is coming from the fact recursive call could 
be only at result affectation line. In this sample it's the line :

CalculateFactorial = Number * CalculateFactorial( Number - 1 )

But I can't imagine a simple way to do the same with my algorithm, 
because copying an array need a For Next recursive call for each item 
... An array is not a Lisp list ...

I may imagine two solutions :
1. Using Lisp paradigm with first() and rest() functions, splitting 
array... But how to build an array reference starting with LBound()+1 
item of the array ?
2. Trying serialize the recursive array to a large String value and use 
an other unserialize function to rebuild the structure ....

Do you know if an other CopyValue already exist ? An other Idea ?

Thank you for your advises !
Patrick

Rem 
--------------------------------------------------------------------------------------------------
Rem                             TEST COPY VALUE CODE
Rem 
--------------------------------------------------------------------------------------------------
Sub TestCopyValue()

    Dim tableau(1 to 3, 1 to 2)
    Dim result As Variant

    tableau(1,1) = "AZERTY"
    tableau(1,2) = 12
    tableau(2,1) = Array("item1", "item2")
    tableau(2,2) = Array(Array("11", "12"), Array("21", "22"))
    tableau(3,1) = "A"
    tableau(3,2) = 99

    result = CopyValue(tableau)
End Sub

' #FONCTION# 
==================================================================
' Nom. ..........: ArrayDim
' Description ...: Un tableau avec les indices de chaque dimension du 
tableau
'                    en parametre. Le nombre maximum de dimension du 
tableau
'                    en parametre est limité à 5 sinon une exception n°9
'                    est émise.
' Parametres ....:
' Syntaxe .......:
' Resultat ..... : La première célule de la première ligne du tableau 
Result(0, 1)
'                    contient le nombre de dimensions. Les lignes 
Result(1, ) à
'                    Result(5, ) contiennent les deux indices LBound() 
et UBound()
'                    de chaque dimension.
' Auteur ........: Patrick
' Modifié .......:
' Remarques .....:
' Relations .....:
' Liens .........:
' Example .......:
Function ArrayDim(anArray As variant) As Variant

    Dim Bounds(0 to 6, 1 to 2) As Long 'Le couple des index 
(LBound,UBound) d'une dimension du tableau
    Dim i As Integer

    on local error goto Exit_Function

    for i = 1 to 6 step 1
        Bounds(i, 1) = LBound(anArray(), i)
        Bounds(i, 2) = UBound(anArray(), i)
    Next

Exit_Function:
    On Error Resume Next
    If not EstVide(Bounds(6, 1)) Then
        Err = 9 'Index hors de la plage définie. Exit !
        Exit Function
    EndIf

    'Par convention, le nombre de dimensions est indiqué
    'dans la première ligne du tableau.
    Bounds(0,1) = i-1
    ArrayDim = Bounds
End Function

' #FONCTION# 
==================================================================
' Nom. ..........: CopyArray
' Description ...: Copie un tableau par valeur de manière récursive.
' Parametres ....: aVariant as variant : Un tableau
' Syntaxe .......:
' Resultat ..... :  Le résultat est toujours un tableau de variant. La 
limite
'                    LBound est toujours 0, il y a donc un offset 
UBound() - LBound()
'                    des indices du tableau original.
' Auteur ........: Patrick
' Modifié .......:
' Remarques .....:
' Relations .....:
' Liens .........:
' Example .......:
Function CopyArray(aVariant() As Variant) As Variant

    Dim result As Variant
    Dim Bounds As Variant
    Dim i1,i2, i3, i4, i5 As Long
    Dim value As Variant

    On local error Goto Erreur

    Set Bounds = ArrayDim(aVariant)
    Select Case Bounds(0,1)
        Case 1
            result = DimArray(Bounds(1, 2) - Bounds(1, 1))
            For i1 = Bounds(1, 1) to Bounds(1, 2) Step 1
                value = aVariant(i1)
                result(i1 - Bounds(1,1)) = CopyValue(value)
            Next
        Case 2
            result = DimArray(Bounds(1, 2) - Bounds(1, 1), _
                                Bounds(2, 2) - Bounds(2, 1))
            For i1 = Bounds(1, 1) to Bounds(1, 2) Step 1
                For i2 = Bounds(2, 1) to Bounds(2, 2) Step 1
                    value = aVariant(i1, i2)
                    result(i1 - Bounds(1,1), i2 - Bounds(2,1)) = 
CopyValue(value)
                Next
            Next
        Case 3
            result = DimArray(Bounds(1, 2) - Bounds(1, 1), _
                                Bounds(2, 2) - Bounds(2, 1), _
                                Bounds(3, 2) - Bounds(3, 1))
            For i1 = Bounds(1, 1) to Bounds(1, 2) Step 1
                For i2 = Bounds(2, 1) to Bounds(2, 2) Step 1
                    For i3 = Bounds(3, 1) to Bounds(3, 2) Step 1
                        value = aVariant(i1, i2, i3)
                        result(i1 - Bounds(1,1), i2 - Bounds(2,1), i3 - 
Bounds(3,1)) = CopyValue(value)
                    Next
                Next
            Next
        Case 4
            result = DimArray(Bounds(1, 2) - Bounds(1, 1), _
                                Bounds(2, 2) - Bounds(2, 1), _
                                Bounds(3, 2) - Bounds(3, 1), _
                                Bounds(4, 2) - Bounds(4, 1))
            For i1 = Bounds(1, 1) to Bounds(1, 2) Step 1
                For i2 = Bounds(2, 1) to Bounds(2, 2) Step 1
                    For i3 = Bounds(3, 1) to Bounds(3, 2) Step 1
                        For i4 = Bounds(4, 1) to Bounds(4, 2) Step 1
                            value = aVariant(i1, i2, i3, i4)
                            result(i1 - Bounds(1,1), i2 - Bounds(2,1), 
i3 - Bounds(3,1), i4 - Bounds(4,1)) = CopyValue(value)
                        Next
                    Next
                Next
            Next
        Case 5
            result = DimArray(Bounds(1, 2) - Bounds(1, 1), _
                                Bounds(2, 2) - Bounds(2, 1), _
                                Bounds(3, 2) - Bounds(3, 1), _
                                Bounds(4, 2) - Bounds(4, 1), _
                                Bounds(5, 2) - Bounds(5, 1))
            For i1 = Bounds(1, 1) to Bounds(1, 2) Step 1
                For i2 = Bounds(2, 1) to Bounds(2, 2) Step 1
                    For i3 = Bounds(3, 1) to Bounds(3, 2) Step 1
                        For i4 = Bounds(4, 1) to Bounds(4, 2) Step 1
                            For i4 = Bounds(5, 1) to Bounds(5, 2) Step 1
                                value = aVariant(i1, i2, i3, i4, i5)
                                result(i1 - Bounds(1,1), i2 - 
Bounds(2,1), i3 - Bounds(3,1), i4 - Bounds(4,1), i5 - Bounds(5,1)) = 
CopyValue(value)
                            Next
                        Next
                    Next
                Next
            Next
    End Select

    CopyArray = result

Exit_Function:
    Exit Function
Erreur:
    TraceError("ERROR", Err, Name, Erl)
    Goto Exit_Function
End Function

' #FONCTION# 
==================================================================
' Nom. ..........: CopyValue
' Description ...: Copie un variant par valeur (de manière récursive 
dans le cas
'                    d'un tableau).
' Parametres ....: aVariant as variant : Un scalaire, sinon un tableau 
ou encore
'                    un objet avec une methode Clone(). Ne supporte pas 
un argument
'                    de type structure.
' Syntaxe .......:
' Resultat ..... :  Une copie du variant. Dans le cas d'un tableau,
'                    le résultat est toujours un tableau de variant. La 
limite
'                    LBound est toujours 0, il y a donc un offset 
UBound() - LBound()
'                    des indices du tableau original.
' Auteur ........: Patrick
' Modifié .......:
' Remarques .....:
' Relations .....:
' Liens .........:
' Example .......:
Function CopyValue(aVariant as variant) As Variant

    Dim result As Variant
    Dim value As Variant

    On local error Goto Erreur

    Rem Clauses appelant une récursion ...
    If IsArray(aVariant) Then
        result = CopyArray(aVariant)
    Rem Clauses pour arrêter la récursion
    ElseIf IsObject(aVariant) Then
        result = aVariant.Clone()
    Else
        'Copie par valeur d'un variant
        Select Case VarType(aVariant)
        Case 8 'String
            result = Left(aVariant, Len(aVariant)) 'Copy value avec la 
fonction 'Left()'...
        Case 0 'Empty
            'exit sans aucune affectation vaut la valeur retour empty...
            'Ne surtout pas essayer d'affecter l'objet 'Nothing'
            Exit Function
        Case 1 'Null
            result = Null
        Case else
            result = aVariant
        End Select
    EndIf

    CopyValue = result

Exit_Function:
    Exit Function
Erreur:
    TraceError("ERROR", Err, Name, Erl)
    Goto Exit_Function
End Function

--
M Patrick GELIN
181 roue d'Arzay
Lieu dit "Saint Martin"
38440 Lieudieu
06 80 32 87 18


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