PureBasic Forums - English

Posted: **Wed Sep 05, 2012 9:50 am**

Need to add the ability to work with a linked list (array, map, etc.) by pointer.

Procedure Test(List x.l())
  List y() = x()
    
EndProcedure

NewList MyList.l()

Test(MyList())

Posted: **Wed Sep 05, 2012 1:52 pm**

LinkedLists, Maps and Array be pushed as a pointer!

Posted: **Wed Sep 05, 2012 2:20 pm**

Already exists even if it's maybe not as elegant as what your code would suggest, see ChangeCurrentElement.

Posted: **Wed Sep 05, 2012 2:38 pm**

Another example.

Code: Select all

Structure a4 
  String.s 
  List x.i() 
EndStructure 

Structure a3 
  List x.a4() 
EndStructure 

Structure a2 
  List x.a3() 
EndStructure 

Structure ax 
  List x.a2() 
EndStructure

Procedure Test(List x.a2()) 
  
  SelectElement(x(),0)
  SelectElement(x()\x(),0)
  SelectElement(x()\x()\x(),0)
  SelectElement(x()\x()\x()\x(),0)
  
  List y.i() = @x()\x()\x()\x()
  
  ForEach y()
    Debug y()
  Next
  
EndProcedure 

Test.ax 

For i=1 To 10 
  If AddElement(Test\x()) 
    For x=1 To 10 
      If AddElement(Test\x()\x()) 
        For y=1 To 10 
          If AddElement(Test\x()\x()\x()) 
            For z=1 To 10 
              If AddElement(Test\x()\x()\x()\x()) 
                Test\x()\x()\x()\x()=z 
                Test\x()\x()\x()\String = Str(i)+Str(x)+Str(y)+Str(z) 
              EndIf 
            Next z 
          EndIf 
        Next y 
      EndIf 
    Next x 
  EndIf 
Next i 
 

Test(Test\x())

Need to get a pointer to the list and work with this list.
The code will be more readable and optimized.

Requires the same result as with the structures, but using lists and arrays.

Code: Select all

*MyStruct.Point
Point.Point

Point\x=1
Point\y=2

*MyStruct = @Point

Debug *MyStruct\x
Debug *MyStruct\y

Posted: **Wed Sep 05, 2012 2:51 pm**

For example:

Code: Select all

Structure a4 
	String.s 
	List x.i() 
EndStructure 
; [...]

Protected *a4.a4 = @x()\x()\x()

ForEach *a4\x()
	Debug *a4\x()
Next

you can not use:

Code: Select all

*Element() = Element()\Element()\Element()

because *Element() itself could be a list, so no way to use it as pointer, as you wish

Posted: **Wed Sep 05, 2012 3:51 pm**

STARGÅTE wrote:you can not use:

I want to add this feature.

Posted: **Wed Sep 05, 2012 4:04 pm**

User_Russian wrote:
STARGÅTE wrote:you can not use:
I want to add this feature.

This is not possible to add, for the reason Stargate explained

Posted: **Wed Sep 05, 2012 9:46 pm**

Polo wrote:
User_Russian wrote:
STARGÅTE wrote:you can not use:
I want to add this feature.
This is not possible to add, for the reason Stargate explained

Why not?
After all, you need the following, with the only difference, then a pointer to the list can be created in any part of the code, not only in the argument of the procedure.

Code: Select all

Structure a4 
  String.s 
  List x.i() 
EndStructure 

Structure a3 
  List x.a4() 
EndStructure 

Structure a2 
  List x.a3() 
EndStructure 

Structure ax 
  List x.a2() 
EndStructure

Procedure Test(List y.i()) 
  
  ForEach y()
    Debug y()
  Next
  
EndProcedure 

Test.ax 

For i=1 To 10 
  If AddElement(Test\x()) 
    For x=1 To 10 
      If AddElement(Test\x()\x()) 
        For y=1 To 10 
          If AddElement(Test\x()\x()\x()) 
            For z=1 To 10 
              If AddElement(Test\x()\x()\x()\x()) 
                Test\x()\x()\x()\x()=z 
                Test\x()\x()\x()\String = Str(i)+Str(x)+Str(y)+Str(z) 
              EndIf 
            Next z 
          EndIf 
        Next y 
      EndIf 
    Next x 
  EndIf 
Next i 


SelectElement(Test\x(),0)
SelectElement(Test\x()\x(),0)
SelectElement(Test\x()\x()\x(),0)
SelectElement(Test\x()\x()\x()\x(),0)

Test(@Test\x()\x()\x()\x())

Posted: **Fri Nov 09, 2012 10:02 pm**

Here is another example.
There is a code in which repeated the same action with different linked lists.

Code: Select all

NewList x1.l()
NewList x2.l()
NewList x3.l()
NewList x4.l()

ForEach x1()
  ; Working with a list.
Next

ForEach x2()
  ; Working with a list.
Next

ForEach x3()
  ; Working with a list.
Next

ForEach x4()
  ; Working with a list.
Next

This is a simple example.
In the real code inside the loop enumeration list items is a lot of code. Duplicate it for each list is not desirable.

I now use a procedure to reduce code size.

Code: Select all

Procedure Test(List x.l())
  ForEach x()
    ; Working with a list.
  Next
EndProcedure

NewList x1.l()
NewList x2.l()
NewList x3.l()
NewList x4.l()

Test(x1())
Test(x2())
Test(x3())
Test(x4())

It would be great if we could get a pointer to list (not to be confused with the current element) and work with it, that is, to refuse procedure.

Code: Select all

NewList x1.l()
NewList x2.l()
NewList x3.l()
NewList x4.l()

For i=1 To 4
  Select i
    Case 1 : List x.l() = x1()
    Case 2 : List x.l() = x2()
    Case 3 : List x.l() = x3()
    Case 4 : List x.l() = x4()
  EndSelect
  
  ForEach x()
    ; Working with a list.
  Next
Next i

Posted: **Fri Nov 09, 2012 11:27 pm**

User_Russian wrote:It would be great if we could get a pointer to list (not to be confused with the current element) and work with it, that is, to refuse procedure.

You could use an array of Lists:

Code: Select all

EnableExplicit

Structure tList
	List x.l()
EndStructure

Dim ListArray.tList(3)
Define i, j

For i=0 To 3
	For j = 1 To 9
		AddElement( ListArray(i)\x() )
		ListArray(i)\x() = (i+1)*1000 + j
	Next j
Next i


For i=0 To 3
	ForEach ListArray(i)\x()
		Debug ListArray(i)\x()
	Next
	Debug "-"
Next i

Posted: **Sat Nov 10, 2012 12:14 am**

I am not sure, if somone could use this code:

Code: Select all

Procedure procGetPointer( *list )
	ProcedureReturn *list
EndProcedure
Prototype.i ptGetPointer( List x.l() )
GetPointer.ptGetPointer = @procGetPointer()

NewList x.l()

For i = 1 To 9
	Debug "List pointer: " + Hex(GetPointer( x() ), #PB_Integer)
	AddElement( x() )
	x() = i
	Debug "Element pointer: " + Hex(@x(),#PB_Integer)
	Debug "-"
Next 
Debug "List pointer: " + Hex(GetPointer( x() ), #PB_Integer)

cu, guido

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