Subject: Re: Packages From: Erik Naggum <email@example.com> Date: Tue, 19 Mar 2002 22:14:02 GMT Newsgroups: comp.lang.lisp Message-ID: <firstname.lastname@example.org> * Drew McDermott | I don't use the property list, value cell, or function cell of either | symbol, so what I'd really like to say is, "Treat these as the same | symbol; they will never occur in the same context, so there will never be | any ambiguity about which is meant." Obviously, this example is | contrived, but this sort of thing has happened to me more than once. So use import. | There seems to be no reason in the world to have to write | | (loop pkg1:for thing in things | when (get thing 'color) | pkg1:collect thing) | | and | | (wait pkg2:for (event e ...) | then pkg2:collect e) | | but that's what I have to do. I cannot fathom how you can do something that produces a problem and think that it is somebody else's fault that it does. Please note that loop does _not_ use symbols for identity, it uses symbols for names. for, in, when, collect, etc, are compared by symbol-name, not eq. | (In the actual example above, 'for' and 'collect' happen to be in the | "CL" package, so the problem, by happenstance, wouldn't arise; I just | chose 'loop' so I could use a familiar macro.) Wrong. for and collect are most definitely _not_ in the common-lisp package. This is so goddamn easy to check. Why did you just go on your assumption? | For these and other reasons, over the years my Common Lisp style has | evolved away from being "symbol-dependent." Whenever possible, I make | sure my macros use local syntax markers from the keyword package only. I | always use tables instead of property lists. I often define variant | symbol types that print something like symbols, and when appropriate read | something like symbols, but differ from symbols in various ways (such as | not being interned until after the first time they are printed). It appears you have based most of this on a subtle confusion. It is becoming increasingly clear to me how damaging it is to learn Scheme first for a (future) Common Lisp programmer. There are so many subtle differences that are unable to produce strong enough hints to a Scheme programmer that he continues to believe the Scheme mindset. A Common Lisp programmer will, on the other hand, get strong enough hints that Scheme is different that he cannot use his Common Lisp mindset in Scheme. This leads Scheme people to believe that Common Lisp is just like Scheme, and Common Lisp people to _know_ that Scheme is a very different language. Moreover, Scheme people do not understand what the Common Lisp people are talking about until they have actually experienced the differences, and most of them write Scheme in Common Lisp, anyway, so they never do. Trying to write Common Lisp in Scheme fails miserably. | On balance I think I would prefer a module system to the package system, | but it's not a strong preference. But they are orthogonal features! Please try to understand this. | And now apparently I have to tack on some verbiage about how I love | "symbol-processing languages," and I despise Scheme (which, believe it or | not, I do, pretty much), and I'm competent to talk about all this because | I once coauthored a book on Lisp programming. Really, the tone on this | newsgroup often sounds like a meeting of a Communist Party cell circa | 1935, with the main item on the agenda being how to detect the | Trotskyites among us. Well, gee, you sure help on the attitude. A newsgroup is what you make it. If you believe you can be a critical outsider _and_ post to the newsgroup you criticize without becoming part of it, you are seriously deluded. Lots of people somehow think that there is a "they" concept of which they are not a part and that it is useful to distinguish between "they" and the critic. This is a _fantastically_ ludicrous position to take. If you post, you are by definition part of the forum, and if you post another hostile message, you are by definition part of problem. This _stupid_ attitude that you can somehow walk into a forum and shout that other people should not shout without actually shouting, yourself, is such a tremendous barrier to peace and progress. If you have to make some remark about other people's "tone" in a hostile tone of your own, at least have the honesty and presence of mind to accept responsibility for making the situation worse, and by implication _preferring_ the hostile tone instead of trying to calm it down. As an aside: meta-comments like that are always hostile because they by their very nature sets up a distinction between the poster and everybody else, the poster somehow being in the moral clear while everybody else is at fault. Hypocrisy is not a feature of civil discussions. Please realize that your emotional response has led you astray: It is not a requirement to say that Scheme sucks, it is generally just a whole lot smarter _not_ to say that Common Lisp sucks. This is not a hate group for Scheme just because Scheme lovers who also keep denigrating Common Lisp are asked to leave. That is such a bogus causality chain that there can be very little credibility in other things you have concluded with the same intellectual sloppiness. Then again, this is precisely the lack of observational skills that cause people to believe Common Lisp and Scheme are so much alike: they stop looking _completely_ when they are satisfied that they have seen "enough", and then they only talk as if the world would never have invalidated whatever they were satisfied seeing if they had continued to look. This is not a good way to cope with a world in constant flux, and even a world you continously see more of is better with your eyes open. /// -- In a fight against something, the fight has value, victory has none. In a fight for something, the fight is a loss, victory merely relief.