Home <--> Work synchronization

What's a pity that major hosters do not offer free version control system. Google, sourceforge - that's all for programming projects.

I'd like to have some simple solution for the synchronization of small notes and todo lists at home and work computers.

I've come across OpenSVN project. The rules contain almost no restrictions on contents. It's slow, but it's quite enough for files <10к. Well, I hope that it will be no more bugs with backups ).

At the work computer with constant connect to Internet I've set up a scheduler, now I'm sure that I Can download everything at the home one, if needed.

Why are Shortcuts Files?

It's a regular joke: guys either e-mail a shortcut to a local file or get angry that at 4 Gb USB devise taken to 3 hour journey for a purpose only a tiny shortcut is placed.

It turned out it was initially planned so:

It had to be possible to copy a shortcut to a floppy disk or send it to a colleague as an e-mail attachment...

Links: Functional programming ebooks

In a subscribe Spb Haskell User Group I've met several interesting links to files garbage with books on the functional programming.

I've dig out Introduction to Functional Programming by Mike Gordon. Judge by the first chapter a lot of text and samples but less mathematics is expecting further. Such a real programmers book.

I do not understand somehow what do they want...

Find an example to show that if V₁=V₂ then even if V₂ is not free in E₁ it is not necessarily the case that
(\V1 V2.E)E₁E₂ = E[E₁/V₁][E₂/V₂]

Mailing List Archive in RSS

Big thanks to Fredrik Carlsson for the responsiveness and the efficient job.

Messages from some mailing lists can be seen not only through web http://archive.netbsd.se, but through any rss-reader.

And now thanks to the fresh-added tag <pre> around the contents it's properly reflected in google-reader.

Links: Powershell in action

I like to study script languages possibilities not from books with artificial samples but during digging real files. More associations remain in memory.

The main thing in the automation is just to remember such a possibility in a right moment.

An interesting article in MSDN Magazine - Light testing with Windows PowerShell

Links: Lisp without parentheses in book

It is recommended to fans of rubber women, alcohol-free beer and lisp without parentheses - G J Chaitin THE UNKNOWABLE

CONTENTS
   1. A Hundred Years of Controversy Regarding the Foundations of Mathematics
   2. LISP: A Formalism for Expressing Mathematical Algorithms
   3. Gödel's Proof of his Incompleteness Theorem
   4. Turing's Proof of the Unsolvability of the Halting Problem
   5. My Proof that You Can't Show that a LISP Expression is Elegant
   6. Information & Randomness: A Survey of Algorithmic Information Theory
   7. Mathematics in the Third Millennium?
   8. Bibliography 

An excellent example of how a good idea can be spoiled. After removing parentheses an author has to comment every(!) line of a source code... otherwise everything is completely confusing.

Running over it, I started to mess about just on the phrase

[is set empty?]

The first thought is... aha it's usual thing - besides parenthesis we add square brackets for easing of understanding. I.e. after translating to human language we get:

(define (is v p)
  (p v))

(define empty? null?)

(is set empty?)

Oops... it turned out it was just a comment. Further it's getting worse huge sconses instead of one call of list, strange "'.

For educational purposes Lisp-1 can be used resolutely, and functions and usual variables may not be separated.

Links: Numerical Computation Guide

An interesting book - Numerical Computation Guide, especially the appendix What Every Computer Scientist Should Know About Floating-Point Arithmetic

For the first time I've met a description of the support of IEEE standards for the calculations with mantissa in C language.

P.S. But why this is not told in universities in study courses dedicated to the programming in C language and the computational modeling?

Links: Pythagorean Triple

Have you known that a right-angled rectangle with integer-valued sides always has an even perimeter? And that the multiplication of all sides is always multiply of 60?

A remarkable article Pythagorean Triple

The programming: 99 bottles

Oh, amazing site - www.99-bottles-of-beer.net It collects a great many programs in different languages printing plain and simple song:

99 bottles of beer on the wall, 99 bottle of beer!
Take one down, and pass it around. 98 bottles of beer on the wall.

98 bottles of beer on the wall, 99 bottle of beer!
Take one down, and pass it around. 97 bottles of beer on the wall.

...

What languages there are not here: ANT, J, K, CLIPS, Erang, Ocaml, 1C, naturally there are C/C++, Java, Perl.

Some exoteric languages made me smile - Ook! (This is for those who read Pratchett),
Shakespeare Programming Language (at least a brief acquaintance with works of the author with the same name is also recommended), Multithreaded Brainf * ck, procmail.

But as the most beautiful solution I unexpectedly chose a program in Refal.

With the printing the beginning of the song all languages cope pretty enough. The simple end spoils everything:

...

2 bottles of beer on the wall, 2 bottle of beer!
Take one down, and pass it around. 1 bottle of beer on the wall.

1 bottle of beer on the wall, 1 bottle of beer!
Take one down, and pass it around. No more bottles of beer on the wall.

No more bottles bottles of beer on the wall, No more bottles bottles of beer!
Go to store and buy some more. 99 of beer on the wall.

In some languages code is short, simple and clear but either incorrectly declines «1 bottles», or gladly reports in the end «0 bottles of beer on the wall». After fixing it becomes huge and confusing.

ANT by using the extensions package ant-contrib demonstrates the all ugliness of XML for recording consecutive actions.

But 1C code looks rather good due to the presence of operator ? in the language. If there is no petty operator + it would be not so bad illustration of imperative approach for solving this problem.

Excel VBA wonderfully demonstrates what terror can come out of it if do not separate logic from visual appearance.

Common Lisp code made me smile — the only program, which actually does what was requested — printing the song. In the language standard there is 'format' function (highly advanced analogue of C printf) its abilities are pretty enough for this song :).

Program in Scheme generates the required string in compile time. There there is a terrifying realization and quite good one.

C++ solution with using templates amazes by its laconism and demonstrates a simple rule-based approach in compile time.

Rule-based forward chaining language CLIPS fits successfully. It's a little bit verbose, but then easy extended.

For some reason neither JESS nor Drools solutions are present. Aren't they unpopular?

Java Exception oriented programming is the joke of the month! throw new BottleExeption(1), and redefine printStackTrace() method %)

Refal is great! Pattern matching is a wonderful tool for the decomposition.

I expected to see something similar in OCalm, but in the beginning they build recursive variant type isomorphic to the song verses and after that the substitution is going on. I have not understood yet either it is an awfully overhead, or a remarkable approach, using effectively the advantages of compile time and run time.

At the same site there is a lot of programs written in different Assembler dialects, Basic and SQL, but they are not so interesting for me.

Programming: GUI - new concepts

Yep.. Eclipse guys are not behind new trends - JFace Data Binding. In Eclipse 3.2 will be analogue of Cocoa Controller Layer.

Links: Lisp books

Learning Lisp - Forum thread with links to Lisp books.

Sample SLIME configuration for productive work