SIGKILL - Random stuff

Emacs/Goatee/Drei - Emacs history

nospam@example.com (Troels Henriksen) — Mon, 02 Oct 2006 20:14:28 +0200

In ye olden days at the MIT Artificial Intelligence laboratory, there was a text editor known as TECO. This text editor was one of the new-fangled visual editors, a concept that can be difficult to understand for many people, as the idea of a non-visual editor is rather alien to most users of modern computational machinery. In all simplicity, a visual editor is one that displays the text being edited - compare to older line, or stream, based editors (DOS/Windows users can type EDLIN at a command prompt to relive the joy, while those of you that have seen the light can use ed or ex). Naturally, TECO's obvious superiority compared to the other text editors of the day resulted in it being massively popular among the hackers at MIT. These hackers, all being highly skilled programmers, engaged in the now cherished tradition of heavily customizing ones tools. This resulted in multiple incompatible macro packages for TECO that all added some new functionality to the editor, but unfortunately, these macro packages were rarely compatible with one another. Two MIT hackers, Richard Stallman and Guy Steele, decided to solve this problem by creating a super-package of all the functionality provided by the various macro packages - and thus was the original EMACS born. This is why Emacs is an acronym for Editor MACroS. Eventually, implementations of the Emacs principles and features appeared on other systems, for example in Multics Emacs (one of the first emacsen to use a Lisp dialect - MacLisp, to be precise) and Gosling Emacs, the first Emacs to run on Unix. In the eighties, Richard Stallman also started working on GNU Emacs, which was forked to produce XEmacs and so forth, but this part of the Emacs tale is boring - everybody already knows it. So instead, I'll go back to 1976 and talk about EINE, the original Emacs for the MIT Lisp Machine, and possibly the first Emacs to be heavily integrated with its run-time environment. EINE eventually begat ZWEI ("ZWEI Was Eine Initially"), the second editor for the Lisp Machine, and when the commercialization of the machines started, ZWEI was used as the editor component to build the final version of Emacs for the Lisp Machines, Zmacs (which was, apparently, really cool). The use of Lisp for the implementation of the editor gave the MIT hackers incredible flexibility and power compared to the previous TECO and assembly-based implementations, and started the now de-facto tradition of using Lisp to write and extend emacsen.

I find it pretty interesting to look into the history and philosophy that was behind these early Emacsen - and sometimes I am saddened that they died out while GNU Emacs became a success, because they had some good ideas here and there. Fortunately, it is actually possible to get hold of the source code for the MIT CADR Lisp Machine! In the extract/nzwei is what I assume to be the actual ZWEI editor. The code is written in an old dialect of Lisp (MacLisp I think), but it's still not hard to read if you know Common Lisp, and it's pretty interesting to see the techniques they used back then. My favorite pieces of code is the various editor commands, and it's especially interesting to compare them to how they are implemented in other, more modern emacsen.

This is a blog, therefore, I must post something narcissistic in every entry. I am going to write a bit about how the Lisp Machine Emacs tradition is being carried (or dragged) on by modern hackers, an effort I am somehow associated with. After the demise of the Lisp Machines, emacsen fully written in Lisp started to die out - the editors of the commercial Common Lisp implementations and Hemlock were all that was left. People switched to GNU Emacs or XEmacs, editors that were often "good enough", yet lacked some of the flexibility, elegance and features of, say, Zmacs. Years later, however the McCLIM developers read the holy scripture and it was revealed to them that McCLIM was required to implement an Emacs-style text editor. Tim Moore, one of the faithful, implemented what is known as Goatee ("Goatee Owes All To Emacs, Evidently"), an Emacs-style text editor component that was used to implement input-editing and text editor fields for McCLIM. However, not all was well - while Goatee did what it was designed for, it did not do much else than this - it was not suited for use as a complete editor, it did not have tight integration with the underlying Lisp system, it provided little in the way of powerful editing tools, its internals were not quite as powerful as they could be, and it did not do syntax-highlighting or many of the other features that are taken for granted these days. Thus, Climacs was created - originally as a project meant to replace the internals of Goatee and Hemlock with more modern code, eventually as a complete implementation of an Emacs-style text editor. And I hope we'll soon come full circle - I'm currently working on (and succeeding at) getting a Climacs-based editing component (named "Drei" in the Lisp Machine tradition) to replace Goatee for all purposes in McCLIM. Once this is done, all McCLIM-based applications will be able to transparently leverage an extremely powerful text editor for all their editing needs, and the user will be able to easily define new editing commands that can be used in all CLIM applications. It's the logical inverse of the GNU Emacs philosophy - instead of putting everything in Emacs, we're putting Emacs in everything. Hopefully, it'll work.

On patriotism

nospam@example.com (Troels Henriksen) — Sat, 27 May 2006 13:14:10 +0200

These days, patriotism is having a considerable effect on the world - especially the USA is having a resurgence of grassroots patriotism. Patriotism is a direct result of the nationalistic doctrines of the 19th and 20th centuries - the doctrines that taught us that we should be unconditionally proud of our contries, consider our own culture and nationality to be superior that of others, and that we should try to convert others to other superior cultural values. Patriotism mostly deals with the two former principles, though the third often follows as a logical imperative.

Patriots are appaled that any of their fellow citizens will not unconditionally support the government or its actions, and they are enraged that any citizen of the state would dare to question or criticize it. This line of thought has lead to great wars (well, at least the Great War), and is perhaps the most dreadful worldview to come out of the nationalistic waves of the previous centuries (possibly excluding stalinism and nazism). It incites conflict between nations and causes stagnation, as there can be no improvement, when there is no criticism.

Why should I unconditionally support my country and its actions? Why should I never question the authority or wisdom of my "leaders" (elected or not)? Why should I be proud of being born in Denmark, no matter the actions of the country? The answer - I shouldn't. I don't feel any particular allegiance to the nation that I live in. If I am prepared to defend it, then it it because I defend the principles on which the nation is built, not because I feel I have an intrinsic duty to fight/die/bleed for my country. Because I don't. I don't owe my country anything just because I was born here, nor do I want to unconditionally defend anything. As a principle, I am not willing to defend any country, though I am perfectly willing to defend certain philosophical principles, the defence of which may at times intersect with the protection of a nation.

Note that I do not despise Denmark - I like the country in which I live, quite a lot actually, but not out of obligation. I admire Denmark for its reasonably fair laws and the spirit of the population, not because it was here I was born (incidentally, in some ways, I admire Sweden quite a bit more).

Now also in English

nospam@example.com (Troels Henriksen) — Mon, 06 Mar 2006 18:05:48 +0100

As of this day, my weblog is available in English as well as Danish. I receive a large number of hits from, I assume, non-Danish-speaking people, so I figured I might as well let them in on the amazingly funny and incredibly insightful posts my weblog is, naturally, dominated by. Also, I am finding myself spending an increasing amount of time communicating via written English; a situation for which I do not consider my current language skills sufficient. Therefore my English posts may be considered a linguistic exercise as well.

I suppose an introduction is in order: my name is Troels Henriksen, I am, at the time of this writing, a Danish 18 year old amateur programmer, a senior at a Danish gymnasium (roughly equivalent to a US high school) and supporter of the philosophy of free software. My favorite programming language is Common Lisp, but I am also interested in Haskell, C++ and Brainfuck.

I am interested in the potential of computer systems, namely their potential to augment human capability, an interest that mirrors my preference for applications with high potential efficiency, instead of those that are merely easy to learn. I am also interested in the theory of computation, because I feel that a solid understanding of the fundamentals of solving problems through programs is a necessity for proper programming. Mostly, however, I spend my time hacking on various Lisp stuff in order to make using my machine more convenient for me. These activities tend to focus on McCLIM, CLIM-desktop and Climacs.

I have no idea how frequently I will update this weblog with English entries - my posting frequency seems to have stabilised around once every three days, but I do not yet know how the English section will fit in. Thus, the best way to find out when I post new stuff, is to use my RSS feed.