Integrating Eiffel in to a COM environment is remarkably easy as the tools that handle the majority of the heavy lifting related to COM development already exist. Programming dynamically with COM is very different than programming statically with Eiffel so I've included common pitfall concept translations for these instances.

This page provides a step-by-step guide, showing you how to use db4o databases within Eiffel for .NET applications.

Step 1: Download Db4o Assembly

The result

First let's see the results of images in different quality levels. The highest quality is 100, the lowest quality is 0.

Original image:

Quality 100 image: (Maybe because the image is too big, 2.6mb, we can't upload it now. Sorry.)

Quality 75 image:

Having looked at code for interfacing Eiffel to C and creating callbacks from C to Eiffel, I frequently found that things were not done properly, resulting in potential memory corruption or crashes.

How do I set the size of an EV_PIXMAP?

Using a C/C++ external in an Eiffel system is pretty easy. Simply do a C/C++ inline and provide the arguments to the C/C++ externals.

When transforming the same system into a multithreaded application one has to pay attention to something else: C/C++ externals that may take a long time to execute.

This is a short tutorial for building web applications with Goanna

It covers the following topics

• Installing all the software you need
• Getting to know Goanna
• A short description on how to develop a web application with Goanna

How it all works

Goanna offers many different services and layers of abstraction.

Intro

We all know about generics as a wonderful help to implement container data structures like lists, sets, bags etc. Much later than Eiffel, object-oriented programming languages like Java and C# have understood that generic parameters are a powerful extension to the type system and remove the need for many casts. So, what else can we do with generics beyond containers?

Since some time Eiffel supports a serialization method completely written in Eiffel. It directly supports serialization to a file or to memory. This example shows how to use this to serialize an arbitrary object structure to a string.

People who are used to other programming languages usually use some kind of rand, rnd or similar function to generate random numbers. This article shows how you can do it in Eiffel.

Generating a random number

The base library's RANDOM class is modeled as a sequence of random numbers.

Sometimes in an application, some actions have to be repeatedly performed in a certain interval. This could for example be some cleanup of external data. To do this I wrote a small class that takes an agent and an interval. <eiffel> indexing description: "Execute an action every interval until stopped." author: "Patrick Ruckstuhl <patrick@tario.org>" date: "$Date$"

On Unix/Linux a daemon is a program that runs in the background independent from the logged in user.

The way to achieve this is normally to directly fork after the execution and let the parent process exit. This results in the child process having lost its parent which leads to the init process automatically inheriting this process.

Introduction

For a beginner the different compilation modes of EiffelStudio can be confusing and I've heard people mention that they don't want to use Eiffel because it's runtime execution is considered too slow. The fact of the matter is, it is not slow! It is only slow when using all or the most aggressive contracts in "workbench" mode, which is by no means the result of an optimized final compilation. Such aggressive checking is sometimes what is needed when developing a new project, and sometime you can throttle back on such aggression. This article explains the various compilation modes and their pros and cons. The results will demonstrate that Eiffel is just as fast as C or C++.