Monday, April 30, 2007

[off topic] Driving Principles of Programming

I often asked on how software development works. To most people unfamiliar with all stinky innards of development process, figuring out how to get anything out of developers is very very tricky. Sometimes people see logic behind what I do - but often they are lost when trying to deal with me.

So as an insight into developer's head I would explain shortly here two of my software development principles. "Shortly" and "two" - because I have managed to date to formulate only one (second) of them and first was well know before I was even born.

1. This is grand principle which regulates lion share of decisions made by software developer. LAZINESS. Some think of it as of bad habit, but in as old programmers' proverb goes to find simplest solution to a problem, assign the problem to laziest programmer you have. In development and programming, laziness is source of all simple decisions which are often by outsiders are seen as "original" or even "genius". To programmers - it's just N days of work saved.

1a. Corollary. In development team with no lazy people, one would hardly see any innovation - or properly working program. After all, non-lazy people can make even pigs flying.

2. It just dawned on me recently and I have managed to formulate my second most used programming principle. EGOISM. (I would claim nothing and rather expect that somebody already did research that before me.) The principle is very simple: make something what would be useful to you and most likely others would find it also useful. Check the Unix made of thousands of small and big utilities - most of the utilities were initially developed for particular purpose of its author himself. But later were also found by others to be useful. Well, Unix itself was made for very particular purpose - and none of its developers even thought that Unix would catch up. Yet it did. Why? Because first and foremost it was useful to its creators. They didn't cared much what others did with it - how egoistic of them!? ;)

2a. Corollary. Excessive non-egoistic programming results in piles of abstract interfaces made to abstract other interfaces which abstract other interfaces. They do not do anything in particular - they are written often because people are told to write something. It is hard to make something useful - if you are just a little gear which needs only to mesh with other such gears. And to mesh better - we need more interfaces, abstraction layers and level of indirection. It also happens to be a generic sickness of many successful projects which in beginning "just work", but authors along the way get bored and start adding needless minor features (by request of vocal user minority) which in the end obstruct core functionality. Program was started as something working - thus became popular. Later on to satisfy needs of few others (here ended the egoism!) features added were not needed by authors themselves (nor (as usually!) were properly communicated by end users to developers) thus ended up being implemented poorly.

That's it for today.

Monday, April 09, 2007

[off topic] [rants] GNU Make - missing features

  1. For all "declaration" nature of make, it is still very very hard to build your own rule out of predefined ones found in make database. e.g. making a rule for new file extension to call existing rule for older file extension is only possible with dumb copy-and-pasting. Now imaging project with hundreds makefiles - all at different times doing such copy-and-pasting: one hell to do maintenance.
  2. Arithmetics. I was really surprised to find that make doesn't have any internal facility for arithmetic expression calculation. Even more so I was surprised when I learned that GNU project doesn't even have such library. Best call - is to call external optional program 'dc' or hope that bash is installed and do arithmetics through it. That bars many accessibility features like progress counter for long build processes. Also obviously renders makefiles unportable.
  3. Clean mechanism to overwrite rules. That's actually what makes proper dependency check implementation impossible. E.g. if you have dependency "a: b" and "a: c" that would really mean "a: b c" - and there is no way to cancel the "a: b" dependency.
  4. List and string routines. Again, mere convenience, yet has performance impact. To put it simply: it is very stupid when to transform file name I have to call several external programs. String manipulation is needed for file name transformations. List routines are needed for proper management of list of targets scheduled to build.
  5. Recursiveness. The dead horse was beaten many times before. Lack of proper recursiveness support bars use of make on very large projects. Or leads to arcane make files understood by few thus having very very low accessibility. One can't require everybody on project to be a make specialist.

Looking at all the rants, my mind instantly points out that the list is precisely difference between make and cons. Last update to cons - pcons - was in 2001 and (thanks to that fact that it was written in Perl) it still works perfectly in all situations I have been to.

I had very ridiculous accident: people using pcons were told to switch to make ("Of course there is no reasons to it - it is just our corporate policy"). Case looked bleak: dumbing down build system back to stone age of make wasn't problem - problem was the lost functionality (the list above). I have advised (and it actually worked) simple solution: put pcons right along with sources and create makefiles with all targets calling cons instead. Worked beautifully - thanks to slim nature of cons/pcons which is written in Perl and has little/no external dependencies.

[off topic] One-liner to make GNU Info usable

Something like this should be shipped along with GNU Info documentation system - to make it any useful:

$ cat ~/usr/bin/iinfo
info --subnodes --output=- "$@" 2>/dev/null | less

Option "--subnodes" tells info to dump everything it has - w/o frigging inhuman document structure. Option "--output=-" tells to dump that all on stdout. The bit "2>/dev/null" is to shut up the stupid useless stuff info spits on stderr. And '| less' bit tells it to behave like proper "man".

Rants. Ironically, even the one-liner cannot make GNU tools any better: they show their age, were not updates in years and do not support most modern things one expects. Searching internet generally brings more and better results than digging outdated GNU documentation. (N.B. GCC of all GNU tools is kind of exception.)