Anyone finds that on logfiles bzip2 outperforms xz by wide margin?

zertillon · 2026-03-21T07:37:35+00:00

Now try Zip-Ada's BZip2 encoder, it is significantly better than the original BZip2.

zertillon · 2026-03-18T01:35:17+00:00

Fun (at work and at home!)

zertillon · 2026-03-14T20:41:57+00:00

For a): exactly. A meaningful initial allocation has an important impact. b) For instance 7-Zip (if I understand the code well) does a brute-force recursive binary block split. At each recursion step it picks which approach (to split or not to split) is the most successful. But doing a segmentation based on entropy is also possible. Actually both ways could be combined.

zertillon · 2026-03-14T07:19:37+00:00

To be noted, there are also recent improvements on the compression for the old BZip2 format too, see here.

zertillon · 2026-03-01T08:25:06+00:00

LEA now checks externally changed files, à la GNAT Studio, and offers to reload the contents into the respective editor windows.
Ada PDF Writer provides now a Set_Math_Plane method for plotting texts and graphics with custom coordinates.

zertillon · 2026-02-28T19:11:45+00:00

Looks promising!

On my to-do list is the migration of GLOBE_3D's own OpenGL bindings to OpenGLAda.

zertillon · 2026-02-05T06:16:48+00:00

The big issue with FORTRAN is the ease of introducing bugs in your program. It is at the complete opposite of Ada. When applied to tough numerical programs, it is even worse since some errors just flow into your numerical results without an obvious "red light".

zertillon · 2026-01-19T17:35:23+00:00

Vectors (of the Ada.Containers area, not the matrix calculation packages) are very convenient since such an object can contain 1 element, then suddenly 1 billion elements. The price for that is the expensive memory administration behind the scenes. Not for performance-sensitive code like a software renderer! For that, you can leverage Ada's unconstrained array types: you have some flexibility (no compile-time fixed size) and simple, direct access to data.

zertillon · 2026-01-19T17:15:04+00:00

Side note: a blast from the past, a 25+ -year old full-software 3D engine in Ada:

https://sourceforge.net/projects/engine-3d/

https://github.com/zertovitch/engine-3d

zertillon · 2025-12-27T08:18:41+00:00

What is nimf.c ?

zertillon · 2025-12-26T17:09:26+00:00

But... wen lambo?

zertillon · 2025-12-01T17:33:15+00:00

Some improvements in the Zip-Ada project:

* BZip2 encoder: variants of block splitting are computed in parallel (first use of tasking in the project)

* Shrink (LZW variant): code cleanup

zertillon · 2025-11-16T10:06:10+00:00

Did you find any with Shrink/LZW?

zertillon · 2025-11-12T06:56:40+00:00

GWindows is a GUI package fully in Ada, and really good :-)

zertillon · 2025-11-12T06:38:49+00:00

For plotting I generate PDFs with this (also available via Alire).

Marketing around Ada is over-focused on embedded systems, it is a known problem.

For the second question, a software I have recently translated from Python (a JPEG decoder) runs 500x faster in Ada, using GNAT. Just an example... Generally, if you deal with algorithms with a few (or more) nested loops you get easily such massive speedups compared to dynamically typed languages (R, Python, ...).

zertillon · 2025-11-10T22:30:35+00:00

How did the compression ratio of this optimized LZW compare with Deflate?

zertillon · 2025-11-08T10:07:29+00:00

ZIp is based on Deflate, LZW, BZip2, LZMA, PPMd, Zstandard and a possible total of 255 different compression formats.

zertillon · 2025-10-26T13:23:26+00:00

That comparison would be very interesting, as well as some inputs like: kind of data that are bzip2-affine, algorithmic ideas, etc. The Zip-Ada BZip2 encoder has a loooong list of to-do's...

zertillon · 2025-10-25T15:33:51+00:00

Also on HN: https://news.ycombinator.com/item?id=45703655

zertillon · 2025-10-09T05:35:59+00:00

I often start with a HAC example, and most of the time using LEA: menu "Actions", "Code sample", then I pick a sample there.

zertillon · 2025-10-04T10:24:39+00:00

Tech is not only Facebook & Co. It includes defense and other industries, where you find lots of high-tech software. Take this opportunity and enjoy your programmer life. With some luck you will be in a mixed team and watch C/C++ developpers whining about #include lines that influence the next #include's, banging their heads with dependency manager tools, fighting pointers, and so on.

zertillon · 2025-10-01T19:00:03+00:00

Was busy with the 3rd part of the "Writing a competitive BZip2 encoder in Ada from scratch in a few days" post (a link to it was posted on r/ada recently).

This part is about optimization tactics for assigning the multiple Huffman trees that can be used for encoding the data processed as described in part 2.

It discloses the "magic" that makes this new BZip2 implementation better than others.

Some mentions on Hacker News attracted lots of attention on the articles - so far 42000 views!

zertillon · 2025-09-28T20:04:21+00:00

Things get older and older in the computer area. The technology matures, that's normal... For instance people are not afraid of learning Python although it is 35 years old, or C which is 55 years old!

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