program LinkedList;  // single linked list

{ Declarations section }

uses MemManager, PascalFunctions;
     
type TMyType = 
     record
       Content: string[10]; // effective payload of the item
                 //Next: ^TMyType;    // recursive definitions not allowed
       Next: word;          // this is the replacement
     end;
     
var Root, Cursor: ^TMyType;
    Str: string[10];
    
procedure AddToList(var S: string[10]);
var TmpCursor, TmpPtr: ^TMyType;
begin
  // create an item for the list
  GetMem(TmpPtr, SizeOf(TMyType));
  TmpPtr^.Content := S;            // give it its payload
  TmpPtr^.Next := nill;            // link to the next item = nil
  
  if Root = 0
  then Root := TmpPtr // the Root gets the item if the list was empty
  else
  begin
    // find the end of the list
    TmpCursor := Root;
    while TmpCursor^.Next > 0 do TmpCursor := TmpCursor^.Next;
    
    // and place the new variable at the end of the list
    TmpCursor^.Next := TmpPtr;
  end;
  
  // !!! do NOT free TmpPtr, its ram is now part of the linked list
end;

procedure DisposeList;
var TmpCursor: ^TMyType;
begin
  while Root > 0 do
  begin
    TmpCursor := Root^.Next;        // make the Cursor point to the next item in the list
    FreeMem(Root, SizeOf(TMyType)); // Dispose of the current item
    Root := TmpCursor;              // and point the Root to the next item
  end;
end;

begin
  { Main program }
  
  MM_Init(3000, 1000); // top of heap = 3000, size of heap = 1000;
  
  // Creation of the linked list
  Root := nill;
  
  // Adding entries to the list
  AddToList('Test1');
  AddToList('Test2');
  AddToList('Test3');
  AddToList('Test4');
  
  // Traversing through the list
  Cursor := Root;
  while Cursor > 0 do
  begin
    Str := Cursor^.Content;       // get the payload
    // do something with Str ...
    Cursor := Cursor^.Next;       // go to next item in the list
  end;
  
  // Get rid of the list (free memory)
  DisposeList;
  
end.