Re: [libreoffice-users] Basic : How to write a CopyValue() recursive function ?
Hi Patrick,
I have currently no time to look at your problem in detail. But in
general byval for an array does not copy the array to the subroutine,
but only hand over a pointer. A discussion of this problem and a
solution using redim preserve is in
https://ask.libreoffice.org/en/question/155179/basic-byval-and-arrays/
Kind regards
Regina
Patrick Gelin schrieb am 06.06.2018 um 09:40:
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
[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 ...:
'
