Yurttas/PL/IL/Ada-95/F/06/trains/trains 05.adb

 1--
 2-- Copyright(C) 1998
 3-- All Rights Reserved. Salih Yurttas, ZCubes, BitsOfCode Software Systems, Inc..
 4--
 5-- Permission to use, copy, modify, and distribute this
 6-- software and its documentation for EDUCATIONAL purposes
 7-- and without fee is hereby granted provided that this
 8-- copyright notice appears in all copies.
 9--
10 
11-- date   : January 1, 1998.
12-- author : Salih Yurttas.
13
14-- trains_05.adb
15
16
17with Ada.Text_IO;
18use Ada.Text_IO;
19
20procedure Trains_05 is
21
22  type Train is(One, Two);
23
24  package EIO is new Enumeration_IO(Train);
25  use EIO;
26
27  procedure Approach_Points is
28  begin
29    Put_Line("...Approach_Points");
30  end Approach_Points;
31
32  procedure Cross_Points(T : in Train) is
33  begin
34    Put(T);
35    Put_Line(" Crossing_Points");
36  end Cross_Points;
37
38  procedure Go_Away_From_Points is
39  begin
40    Put_Line("   Go_Away_From_Points...");
41  end Go_Away_From_Points;
42
43  task Points is
44    entry Cross(T : in Train);
45  end Points;
46
47  task body Points is
48  begin
49    loop
50      accept Cross(T : in Train) do
51        Cross_Points(T);
52      end Cross;
53    end loop;
54  end Points;
55
56  task Train1;
57
58  task body Train1 is
59  begin
60    Approach_Points;
61    Points.Cross(One);
62    Go_Away_From_Points;
63  end Train1;
64
65  task Train2;
66
67  task body Train2 is
68  begin
69    Approach_Points;
70    Points.Cross(Two);
71    Go_Away_From_Points;
72  end Train2;
73
74begin
75
76  null;
77
78end Trains_05;