Gautier de Montmollin

In the Ada world, we are surrounded by impressive and professional tools that can handle large and complex projects. Did you ever dream of a tiny, incomplete but compatible system to play with? Are you too impatient, when developing small pieces of code, for long compile-bind-link-run cycles? Are you a beginner intimidated by project files and sophisticated tools? Then HAC (the HAC Ada Compiler, or the Hello-world Ada Compiler) is for you.

HAC is a revival of the SmallAda project, which supported the "Pascal subset" plus tasking.

If you open the AZip application with a can opener, it will look like an Ada programmer's paradise: you'll find Ada on all levels:

1. the AZip user interface (UI framework specific);
2. the AZip abstract application layer (platform-independent);
3. the archive and data compression library (Zip-Ada);
4. the user interface framework (GWindows);
5. the run-time library (GNAT's).

We will quantify this.

Portability is matched on three different definitions of the word:

1. platform-independence for the abstracted part and the Zip-Ada library - no porting effort at all there;
2. you can easily port the user interface layer since most of the job is done in the abstracted part;
3. no installation needed: the version built on GWindows is contained in a single executable file and can be run from a USB stick; it can be even run in a stealth mode, without writing settings to the registry of the host system.

We will show a new Trained Compression generic plug-in, which can leverage prior information about the data to be transmitted for reducing further raw compressed streams. We will also present a pick-and-choose technique feature called "Preselection" for improving the Zip archiving process.

The Zip-Ada library has met over the years the needs of several professional users who need the file archiving features, or the data compression features to reduce storage and shorten transmission times. We will show the evolution of this full-Ada portable library and the advantages of using it.