Demystifying Iron Ruby in .NET

The Hello World Program

This section will illustrate how to create your first Hello World program using the Ruby language in the .NET Framework context, by loading the corresponding IronRuby project template from the Visual Studio 2010 IDE. Hence, first, be sure that IronRuby is properly installed then select the IronRuby language from the Visual Studio New Project template section. Here, we shall notice several project types have already been loaded to choose from as in the following.

Here choose Console Application and assign a meaningful project name because this first "hello world" program will elaborate through a typical REPL interactive interpreter at the command shell. Thereafter, notice that in the Solution Explorer, the program. rb has been automatically created which could be either renamed or remain the same to operate in the current solution. Hereby, it is not a big deal to implement the first "Hello World" program in Ruby, it could just be done using simply put methods of the Ruby programming construct.

Listing 1. string “Hello World” displaying.

puts "Hello World"

We can also integrate some typical OOP constructs to accomplish this task. Hence, just place the following code in the program.rb file that contains a class named Test. The "Hello World" string will be displayed via the method Method_Test where we are passing the second argument via command line construct.

Listing 2. OOP construct demonstration in IronRuby.

# Class declaration
class Test
  
  # Method definition
  def Method_Test
    # Displaying output using 'puts'
    puts "Hello #{@arg}"
  end
end
# Class end

# Class initialization 'Object creation'
obj1 = Test.new("Ajay")

# Method calling
obj1.Method_Test

Once done with such coding, save the entire solution and build it either through the F6 button or from the menu and observe the output. Simple! We can see the output from Visual Studio 2010's built-in Ruby interactive shell in the following.

Note. It is not necessary to rely only on Visual Studio to compile this Ruby program. Instead, we can use other editors like Notepad++ to do it.

Or by using the ir.exe utility at the Windows command prompt. Here, the ir.exe utility is doing both operations, the interpretation of the code as well as yielding the output, by executing the following command.

Note. The Ruby source code file can be placed anywhere in the system memory when compiling using ir.exe.

However, we have encountered a couple of OOP's constructs (for instance class, constructor, methods, and so on as in a typical C# or VB.NET code) in that sample, but we needn't bother to delve into such concepts in this scenario because the simple "Hello World" printing can be done using the puts method of Ruby programming.

Elementary Programming Constructs

IronRuby is truly an object-oriented programming language. Ruby programming is also capable of operating an entire essential OOP implementation in a similar fashion that C# and VB.Net. The Ruby language is generally run in an interpreted atmosphere and does most of its operation at runtime, hence it is modifiable at runtime. We shall briefly discuss the rudimentary programming construct of the Ruby language, like how to declare a variable, how data types are dynamically allotted, and how to play with essential arrays and method declaration constructs in the forthcoming section.

Variables and Data Types

The type information of variables while the declaration is typically undefined in IronRuby programming because of its dynamically typed language nature. All the data types are assigned implicitly. Here, we are declaring a variable as an "item" whose type identifier is missing as in the following.

Listing 3. numeric value assignment to a variable.

item = 1

So, if we have assigned numeric data to an undefined variable then we can easily conclude that the variable "item" is an integer type. Moreover, if we assign any string type data to any variable then it‘ll automatically be referred to as a string data type as in the following.

Listing 4. String value assignment to a variable

name = "ajay"

Note. Coding in IronRuby is a strictly case-sensitive language like C# programming and all the other languages derived from the C language.

Array

Arrays in IronRuby are mutable unlike C# and can be defined using square brackets to assign a range of values to a variable such as in the following.

Listing 5. Array's declaration

days = ['Sunday', 'Monday', 'Tuesday']
puts days.join(', ') + '!'

As in C#, the following code sample shows an array of integer types.

Listing 6. numeric array declaration

Age = [23, 45, 12, 78]

Note. Comments can be declared by the # symbol in IronRuby code that literally instructs the compiler not to execute the specific line of code.

Function

Functions or methods are pieces of code that can be called or invoked anywhere in the source code or API. Methods can be defined by the def keyword in the Ruby language and their bodies typically culminate in an end keyword.

Listing 7. Function body declaration

def Method_Test
  # code...
end

Note. It is redundant to terminate the code instruction line with a semicolon (;) in IronRuby.

Final Words

This article has showcased the comprehensive process of IronRuby installation in the .NET framework in a step-by-step manner and also covered other essential properties configuration for IronRuby development environments. The First “Hello World” program has provided a basic overview of IronRuby, like how to code and compile Ruby programs in the .NET Framework context. Moreover, we have delved deeper by discussing the importance of the Dynamic Language Runtime (DLR) and mechanics behind the IronRuby open-source nature, which enables the execution of Ruby programs over any platform such as Mac, Windows, and Linux. At the end of the article, we have explored the fundamental constructs of the Ruby language such as declaration and initialization, data types, functions, and array constructs. In a few words, this article has explored the underlying techniques used to implement code generation and dynamic applications during the development, build, and runtime phases of an IronRuby application.

Reference

1. https://github.com/ironlanguages
2. http://ironruby.codeplex.com/releases
3. http://www.techrepublic.com/
4. http://msdn.microsoft.com/en-us/magazine/dd434651.aspx
5. http://www.codethinked.com