Copy List Element

[IdeasVacuum]

We have Copy List, works like a charm.

Would be very nice to have Copy List Element - especially for Structured Lists.

[davido]

@IdeasVacuum,

I've used this code; would this work for you?

Code: Select all

Structure az
  Coin$
  Pence.i
EndStructure
Global NewList a.az(), NewList b.az()
Global *aPTR, *bPTR

With a()
  AddElement(a())
  \Coin$ = "Florin"
  \Pence = 24
  AddElement(a())
  \Coin$ = "Shilling"
  \Pence = 12
EndWith
AddElement(b())
With b()
  \Coin$ = "Half Crown"
  \Pence = 30
EndWith

ForEach a()
  With a()
    Debug \Coin$ + " - " + \Pence
  EndWith
Next a()
*aPTR = @a()
AddElement(b())
*bPTR = @b()
CopyStructure(*aPTR,*bPTR,az)

Debug "___________"
ForEach b()
  With b()
    Debug \Coin$ + " - " + \Pence
  EndWith
Next b()

[mk-soft]

You don't need pointers.

DestListElement() = SourceListElement()

Code: Select all

Macro CopyListElement(Element, DestList, Location=#PB_List_Last)
  CompilerSelect Location
    CompilerCase #PB_List_After
      AddElement(DestList) : DestList = Element
    CompilerCase #PB_List_Before
      InsertElement(DestList) : DestList = Element
    CompilerCase #PB_List_First
      ResetList(DestList) : AddElement(DestList) : DestList = Element
    CompilerCase #PB_List_Last
      LastElement(DestList) : AddElement(DestList) : DestList = Element
  CompilerEndSelect
EndMacro


Structure az
  Coin$
  Pence.i
  List Name.s()
EndStructure

Global NewList a.az(), NewList b.az()

With a()
  AddElement(a())
  \Coin$ = "Florin"
  \Pence = 24
  AddElement(\Name())
  \Name() = "100"
  AddElement(\Name())
  \Name() = "200"
  
  AddElement(a())
  \Coin$ = "Shilling"
  \Pence = 12
EndWith

AddElement(b())
With b()
  \Coin$ = "Half Crown"
  \Pence = 30
EndWith

Debug "*** List a()"
ForEach a()
  With a()
    Debug \Coin$ + " - " + \Pence
    ForEach \Name() : Debug \Name() : Next
  EndWith
Next a()

Debug "*** Do copy and change"
SelectElement(a(), 0)
CopyListElement(a(), b(), #PB_List_First)

ClearList(a()\Name())
AddElement(a()\Name())
a()\Name() = "999"
AddElement(b()\Name())
b()\Name() = "300"

Debug "*** List a()"
ForEach a()
  With a()
    Debug \Coin$ + " - " + \Pence
    ForEach \Name() : Debug \Name() : Next
  EndWith
Next a()

Debug "*** List b()"
ForEach b()
  With b()
    Debug \Coin$ + " - " + \Pence
    ForEach \Name() : Debug \Name() : Next
  EndWith
Next b()

[IdeasVacuum]

Hi mk-soft

I do of course know how to copy, but I think a PB Function for the task should be available. I copy Elements more often than I copy whole Lists.

[davido]

@mk-soft,
Thank you for the excellent Macro.
I'll be using this instead of my rather crude method.

[Trond]

You mean like this?

Code: Select all

CopyStructure(a(), AddElement(b()), structure)

a() returns the address of the current structured element, AddElement(b()) also returns the address (of the new element).

[IdeasVacuum]

Hi Guys, thanks for all the interest shown in this post. Sorry I missed you out first time around davido!

@Trond

Something like this pseudo code:

Code: Select all

NewList MyList01.BigishStructure()
NewList MyList02.BigishStructure()

;Add Data Elements to List01. List02 is empty, then later:

ForEach MyList01()

         If (MyList01()\dMagicNumber = 3.333333)

                 CopyElement(MyList01(), MyList02()) ;New Element automatically added to List02
         EndIf
Next

[Trond]

That is exactly what my code does.

Code: Select all

NewList MyList01.BigishStructure()
NewList MyList02.BigishStructure()

;Add Data Elements to List01. List02 is empty, then later:

ForEach MyList01()

         If (MyList01()\dMagicNumber = 3.333333)

                 ;New Element automatically added to List02
                 CopyStructure(MyList01(), AddElement(MyList02()), BigishStructure)
         EndIf
Next

[mk-soft]

@Trond

You do not need to specify the structure. Purebasic does that automatically.
Besides you don't know where the element will be added. Beginning, end, middle?

For IdeasVacuum once the macro name changed!

Code: Select all

Macro CopyElement(ActualElement, DestList, Location=#PB_List_Last)
  CompilerSelect Location
    CompilerCase #PB_List_After
      AddElement(DestList) : DestList = Element
    CompilerCase #PB_List_Before
      InsertElement(DestList) : DestList = Element
    CompilerCase #PB_List_First
      ResetList(DestList) : AddElement(DestList) : DestList = ActualElement
    CompilerCase #PB_List_Last
      LastElement(DestList) : AddElement(DestList) : DestList = ActualElement
  CompilerEndSelect
EndMacro

Structure udtData
  iVal.i
  sVal.s
EndStructure

NewList MyList01.udtData()
NewList MyList02.udtData()

AddElement(MyList01())
MyList01()\iVal = 1
MyList01()\sVal = "Hello World!"

AddElement(MyList01())
MyList01()\iVal = 2
MyList01()\sVal = "I Like PureBasic!"

ForEach MyList01()
  If MyList01()\iVal = 2
    CopyElement(MyList01(), MyList02())
  EndIf
Next

ForEach MyList02()
  Debug MyList02()\sVal
Next

If you need the native in Purebasic, or if you create the macro yourself, I don't know exactly.

[Little John]

You mean like this?

Code: Select all

CopyStructure(a(), AddElement(b()), structure)

a() returns the address of the current structured element, AddElement(b()) also returns the address (of the new element).

Besides you don't know where the element will be added. Beginning, end, middle?

This is known, of course.

Adds a new empty element after the current element or as the first item in the list if there are no elements in it.

[mk-soft]

@Little John

I know that too,
but I wanted to have the function 'CopyElement(SourceElement(), TargetList() [, Location])' exactly like the function 'MergeLists(SourceList(), TargetList() [, Location])

But I think everyone can build such macros themselves.

Code: Select all

;-TOP

Macro CopyElement(SourceElement, TargetList, Location=#PB_List_Last)
  CompilerSelect Location
    CompilerCase #PB_List_After
      AddElement(TargetList) : TargetList = SourceElement
    CompilerCase #PB_List_Before
      InsertElement(TargetList) : TargetList = SourceElement
    CompilerCase #PB_List_First
      ResetList(TargetList) : AddElement(TargetList) : TargetList = SourceElement
    CompilerCase #PB_List_Last
      LastElement(TargetList) : AddElement(TargetList) : TargetList = SourceElement
  CompilerEndSelect
EndMacro

Macro MoveElement(SourceElement, TargetList, Location=#PB_List_Last)
  CompilerSelect Location
    CompilerCase #PB_List_After
      AddElement(TargetList) : TargetList = SourceElement : DeleteElement(SourceElement)
    CompilerCase #PB_List_Before
      InsertElement(TargetList) : TargetList = SourceElement : DeleteElement(SourceElement)
    CompilerCase #PB_List_First
      ResetList(TargetList) : AddElement(TargetList) : TargetList = SourceElement : DeleteElement(SourceElement)
    CompilerCase #PB_List_Last
      LastElement(TargetList) : AddElement(TargetList) : TargetList = SourceElement : DeleteElement(SourceElement)
  CompilerEndSelect
EndMacro

; ----

Structure udtData
  iVal.i
  sVal.s
EndStructure

NewList MyList01.udtData()
NewList MyList02.udtData()

AddElement(MyList01())
MyList01()\iVal = 1
MyList01()\sVal = "Hello World!"

AddElement(MyList01())
MyList01()\iVal = 2
MyList01()\sVal = "I Like PureBasic!"

AddElement(MyList01())
MyList01()\iVal = 3
MyList01()\sVal = "Powered by Purebasic!"

AddElement(MyList01())
MyList01()\iVal = 4
MyList01()\sVal = "End!"

ForEach MyList01()
  If MyList01()\iVal = 2
    CopyElement(MyList01(), MyList02())
  ElseIf MyList01()\iVal = 3
    MoveElement(MyList01(), MyList02(), #PB_List_First)
  EndIf
Next

Debug "List 1"
ForEach MyList01()
  Debug MyList01()\sVal
Next
Debug "List 2"
ForEach MyList02()
  Debug MyList02()\sVal
Next

[Little John]

but I wanted to have ...

That's fine, but it wasn't about your personal preferences.
The point was that you made a false statement about Trond's code that needed correcting.

[mk-soft]

Wasn't my intention either.

I just wanted to say that, because you have to set the current target element yourself and specify the structure.

Sorry