Using MakeArray to create a type of (Push/Pop) Array Stack

[kevin]

  Using MakeArray to create a type of (Push/Pop) Array Stack

  in this example we treat a global Array called INFO of type TINFO as the current record.   If we need to change records we can push the info() handle to a stack,  fill the array with data again and then later retrieve it.    
 
 

PlayBASIC Code: [Select]

      Type tInfo
            Name$
      EndType

      Dim InfoStack(1000)   

      Makearray info().tInfo
      
      

Function getStackCount()
      Count=InfoStack(0)
EndFunction Count
      
      
      // ---------------------------------------------------------
      //  Push the current HANDLE of our global INFO array
      //  to our STACK
      // ---------------------------------------------------------

Function PushInfo()
   
      // Get to the number of items on our stack
      Offset=InfoStack(0)+1   
   
      // move the array handle 
      InfoStack(Offset) = info().tinfo
      #print "Handle:"+str$(InfoStack(Offset))

      // clear this handle out once it's been moved out
      deletearray info() 
      
      // Store the stack position      
      InfoStack(0) = Offset   
   
Endfunction      
            

      // ---------------------------------------------------------
      //  Push the current HANDLE of our global INFO array
      //  to our STACK
      // ---------------------------------------------------------

Function PopInfo()
   
      // Get to the number of items on our stack
      Offset=InfoStack(0)   
      if Offset>0   

         // release the current array using UNDIM
         undim info()

         // move the array handle 
         info()=InfoStack(Offset)

         // Store the stack position after the delete      
         InfoStack(0) = Offset-1   
         
      endif   
Endfunction      
            
                  

Function ShowCurrentInfoDetails()
      Status = getArrayStatus(info())   
      if Status      
         count=getArrayElements(info())
         print "Info("+str$(count)+") as tInfo" 
         for lp=0 to count
               Message$+=info(lp).Name$+", "            
         next
         print Message$   
         y=getcursory()
         line 0,y,getsurfacewidth(),y   
         setcursory y+10
      else
      
         print "info() is empty"   
      endif   
   
EndFunction



      // ---------------------------------------------------------
      //  Fill Info
      // --------------------------------------------------

Function Fill_Info()
      count=rndrange(1,10)
      dim info(count) as tINfo
      
      for lp =0 to count
         info(lp).Name = "Name:"+str$(lp)
      next
   
EndFunction




      // ---------------------------------------------------------
      //  USAGE EXAMPLE ------------------------------------------
      // ---------------------------------------------------------
      
      ink $00ff00
      print ""
      print "---[Push The Stack]-------------------"
      print ""
      ink -1

   
      for lp=1 to 5   
            
         // Fill info with random junk         
         Fill_Info()
         
         
         // Show what's in info currently
         ShowCurrentInfoDetails()   
         
         //  push this array onto our stack 
         // so we can recall it later   
         PushInfo()
      next


      ink $00ff00
      print ""
      print "---[Info State]-------------------"
      print ""
      ink -1

         ShowCurrentInfoDetails()   

      print ""
      print ""


      ink $00ff00
      print ""
      print "---[POP the stack]-------------------"
      print ""
      ink -1
      
      while  getStackCount()<>0
         


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