Feature:
Immediate .NET Code Execution

Overview

Possible usages for Immediate .NET Code Execution: (This list is not exhaustive!)

• Evaluate complex expressions (like a 'scientific' calculator!).
• Design and test objects, functions and algorithms. No save-to-file is required until you want to.
• Use the objects of the .NET framework, test their behavior, without worrying about directories and project files. You can simply paste and run sample code within the program. Want to check the behavior of a .NET class or function? Just type a test expression, and you will get the answer.

Program Features:

• Immediate Code Execution for expressions, loose statements and functions.
• Execute code stored in external libraries and code files, or in a loose class or function declaration.
• Choose the language you prefer: C#, VB.NET, J#, JScript, or add more languages.
• Attach a .NET Debugger to control the execution of your input.
• Save your sessions on your disk, and recall them later with all input history preserved.

Getting Started

Create a new Immediate Execution session (File | New File, then select Immediate Execution). The window layout for the session is presented in Figure 1.

Figure 1. Immediate execution session: window layout.

1. The Input Type list lets you choose the type of your input. The following operations are supported:
   • Evaluate expressions (see step 2). This type is selected by default.
   • Execute function bodies (any procedure that returns a value)
   • Execute loose statements.
   In this tutorial we will see how to evaluate expressions. Therefore, select Expression as the input type.
2. Next to the Input Type list is the Input Area, where you enter expressions to evaluate, and statements to execute. Below are some examples of expressions you may want to try (C#, VB.NET). See here for instructions on how to change the language.
   • 2 + 3*Math.Exp(5)
   • ControlPaint.LightLight(SystemColors.Highlight)
   • System.IO.Directory.GetDirectories("c:\\windows\\assembly\\gac")
3. The Execute button evaluates the instructions or expressions you enter in the Input Area. Note that the program will attempt to evaluate the input if you press Enter while typing an expression. The Execute button has a shortcut key (F9), and the same command can be found under the Run menu.
4. Once you press the Execute button, the program will display the result, and/or any error encountered. Results are collected in the history display occupying the top portion of the window.
5. To get more data for the selected result, open the Properties Window (F4). The properties window will display all available attributes for the result and, when applicable, show a graphical representation for it.
6. You can reuse some previously entered expressions or statements by double-clicking the corresponding row. Double-clicking a row will copy the expressions or statements to the input zone. You can therefore modifiy existing entries, and save a lot of time instead of retyping entire lines of expressions and statements.
7. Advanced users will need to switch to Code View to add custom variables, functions, and full class declarations that can be called directly from the Input Area.

Advanced Users

Custom Variables and Methods

To add code for variables and methods, switch to Code View. Select (ImmediateExecutionSession) > Declarations in the Fragment List on the left, and add the code for variables and methods in the text editor. Since these variables and methods are in the same class than the input to evaluate, you can use them directly without providing the fully qualified name of the variables and methods (Figure 2a).
> Note: the Declarations fragment uses the namespace and imports provided in the Build Options properties.

Custom Class Declarations

To add additional namespace/class declarations, switch to Code View. Select Build Options > UserCode in the Fragment List on the left. Add the code for new namespaces and classes. Because the UserCode is in a separate unit from the input code, you have to use the fully qualified name of static methods, and provide the appropriate namespaces when instanciating a class (Figure 2b).
> Note: the UserCode fragment does not use the imports found in the Build Options, you must provide namespace imports as if it was a separate file. See also this topic.

Figure 2. Filling (top) the Declarations and (bottom) the UserCode fragments.

Configuring Compile Options

In most basic cases, you don't have to do anything else to execute code as you write it. Simply type in an expression or statements, press the Execute button, and the program will evaluate and display the result.

However, there are cases where you want to change some settings, such as the language and referenced files and assemblies. This topic explains how to change these settings.

Copyright © Q. Binh Dam 2004-2007. Last modified: 22 June 2008.