Delphi 2009 Generic Container Unit (generics.collections) [2]: tqueue<t>

Tqueue and Tstack, one is the list of queues, one is the stack list; One is advanced first out, one is advanced later out.

Tqueue has three main methods, one attribute:

Enqueue (Row), dequeue (column), Peek (see the next element to be out);

Count (total elements).

This example effect chart:

Code files:Unit Unit1;
Interface
Uses
Windows, Messages, sysutils, variants, Classes, Graphics, Controls, Forms,
Dialogs, Stdctrls;
Type
TForm1 = Class (Tform)
Memo1:tmemo;
Button1:tbutton;
Button2:tbutton;
Button3:tbutton;
Procedure Formcreate (Sender:tobject);
Procedure Formdestroy (Sender:tobject);
Procedure Button1Click (Sender:tobject);
Procedure Button2click (Sender:tobject);
Procedure Button3click (Sender:tobject);
End
Var
Form1:tform1;
Implementation
{$R *.DFM}
Uses generics.collections; {Delphi 2009 New generic Container Unit}
Type
TRec = Record
name:string;
Age:word;
End
Var
queue:tqueue<trec>; {Defines a generic Tqueue class that specifies the TREC record to use for the definition above}
Establish
Procedure Tform1.formcreate (Sender:tobject);
Begin
Queue: = Tqueue<trec>. Create;
Memo1.clear;
Button1.caption: = button1.caption + ' row ';
Button2.caption: = button2.caption + ' out ';
Button3.caption: = button3.caption + ' next column ... ';
End
Release
Procedure Tform1.formdestroy (Sender:tobject);
Begin
Queue.free;
End
{row: Enqueue}
Procedure Tform1.button1click (Sender:tobject);
Var
Rec:trec;
Begin
Rec. Name: = Stringofchar (Char (+ Random (26)), 3);
Rec. Age: = Random (150);
Queue.enqueue (REC);
Text: = Format (' Total current queue members:%d ', [Queue.count]);
{Let Memo1 match display}
MEMO1.LINES.ADD (Format ('%s,%d ', [Rec.] Name, rec. Age]));
End
{column: Dequeue}
Procedure Tform1.button2click (Sender:tobject);
Var
Rec:trec;
Begin
If Queue.count = 0 then Exit;
Rec: = Queue.dequeue;
ShowMessage (Format ('%s,%d ', [Rec.] Name, rec. Age]));
Text: = Format (' Total current queue members:%d ', [Queue.count]);
{Let Memo1 match display}
Memo1.Lines.Delete (0);
End
{Next column element: Peek}
Procedure Tform1.button3click (Sender:tobject);
Var
Rec:trec;
Begin
If Queue.count = 0 then Exit;
Rec: = Queue.peek;
ShowMessage (Format ('%s,%d ', [Rec.] Name, rec. Age]));
End
End.