Example 2

In Example 1, we said nothing about a constructor used to create an instance of the Primitives class. In Example 2, we will show how this is done.

In fact, in Example 1, APL supplied a default constructor, which is inherited from the base class (System.Object) and is called without arguments.

Example 2 will extend Example 1 by adding a constructor that specifies the value of ⎕IO.

Load the workspace aplclasses2.dws from aplclasses2, then display the Primitives class:

      ↑⎕SRC APLClasses.Primitives
:Class Primitives                      
:Using System                          

    ∇ CTOR IO                          
      :Implements constructor          
      :Access public                   
      :Signature CTOR Int32 IO         
      ⎕IO←IO                           
    ∇                                  

    ∇ R←IndexGen N                     
      :Access public                   
      :Signature Int32[]←IndexGen Int32
      R←⍳N                             
    ∇                                  

:EndClass ⍝ Primitives                 

This version of Primitives contains a constructor function called CTOR that simply sets ⎕IO to the value of its argument. The name of this function is purely arbitrary.

Using this version, build a new .NET Assembly using File/Export… as before. Remember that the Build runtime assembly checkbox is unchecked.

Figure 1: aplclasses2_1

Figure 2: aplclasses2_2

program.cs

The following C# source, called aplclasses2\Framework\program.cs, will be used to call the new version of our Dyalog.NET class.

      using System;
      using APLClasses;
      public class MainClass
            {
            public static void Main()
                  {
                  Primitives apl = new Primitives(0);
                  int[] rslt = apl.IndexGen(10);

                  for (int i=0;i<rslt.Length;i++)
                  Console.WriteLine(rslt[i]);
                  }
            }

The program is the same as in the previous example, except that the code that creates an instance of the Primitives class is simply changed to specify an argument; in this case 0.

Primitives apl = new Primitives(0);

Using VS, open the solution file d:\aplclasses\aplclasses2\Framework\project.sln and view program.cs.

Figure 3: aplclasses2_3

Then click Debug/Start Without debugging (or press Ctrl+F5) to run the program. The results are shown in a console window.

Figure 4: aplclasses2_4