Comments on: Explaining Lisp to my Father

By: Jake

Jake — Thu, 24 Jul 2008 22:52:25 +0000

@Jayrell:

The school of hard knocks, my man!

What high school let you graduate with the double whammy of almost unreadable grammar and the inability to support your own arguments?

“Besides a mathematical inclination, an exceptionally good mastery of one’s native tongue is the most vital asset of a competent programmer.”

By: Jayrell Fall

Jayrell Fall — Thu, 24 Jul 2008 03:43:23 +0000

these are terrible analogies. what school did you get a CS degree at without having been exposed to LISP?

By: Raphael

Raphael — Tue, 22 Jul 2008 13:53:04 +0000

Maybe you could compare lambdas to the salad bar at pizza hut. You’re able to provide some money and you also specify how you want to assemble your plate from their stuff.

As soon as you provide the input, the restaurant lets you at the salad bar, in which case you generate your own output.

By: JS

JS — Mon, 21 Jul 2008 19:27:05 +0000

I don’t understand why the difficulty in explaining Lisp. The magic of this language, as you know, is all in the macros and the lambdas. These could be thought of as nothing more than a set of tools designed to make other specialized tools tailor-made to solve specific programming problems. While it is true that you can extend languages like C++/Python/Java with libraries, it is comparatively more difficult to do so. As a result, these languages tend to encourage the programming style where you contort your problem to fit the tools you have available on hand for solving problems rather than augmenting your tool set with the right tools for the job.

By: Mohamed Samy

Mohamed Samy — Mon, 21 Jul 2008 17:46:26 +0000

Does it have to use metaphors? How about “We write programs to automate mundane tasks by making a machine do them for us, but when the problem get’s too complex, Lisp makes it possible to automate the programming operation itself, by writing a program to write the program for you”.

About closures: Most languages take a set of commands and executes them, but doesn’t do much besides the execution. I tell the language to do X and it’s done. With closures I can do stuff in the language with the commands themselves. I can tell the computer to take those commands and, say, execute them every 5 seconds or in reverse order or combine them with other commands to form a bigger program.

By: Greg M

Greg M — Mon, 21 Jul 2008 17:36:55 +0000

Well done Jake a solid explanation for a simpleton like me. Except I think that Charles Dickens could have benefited from some brevity in his writing. Sure his famous name tells us we should love, but waxing poetic for a page and a half about a piece of paper on the desk in the corner of the room makes me sick. It definitely was the worst of times.

By: Lisette

Lisette — Mon, 21 Jul 2008 16:47:47 +0000

Asphalt?

Explaining spelling to my brother. Sorry, couldn’t resist.

Loved the post.

By: ken

ken — Mon, 21 Jul 2008 16:40:37 +0000

I like the woodworking analogy, but I wouldn’t say Lego. I think one of the fundamental features of Lisp is that it’s written in itself.

So when you’re programming in Java, you’ve got metal tools (compiler, profiler, etc.) for shaping wood (your program). If you want a new tool, you have to find a guy with a metal shop — so nobody does. You have the tools you’re given, and that’s that.

But when you’re programming in Lisp, you’re writing in the same stuff the language uses. It’s more like metal working. If you need a new tool, machine yourself one. Now you’ve got new tools to bring to bear on the problem. You end up with your solution, and also a new set of tools specifically designed for it.

This is why Lisp makes you more productive: not because of any particular tool it gives you (like Perl’s regexps), but because you can build your own.

By: JanS

JanS — Mon, 21 Jul 2008 15:57:34 +0000

Laurie,Cory: Thanks, great stuff.
Oh, and about other languages having these features too: Now, when you talk about dynamic languages, that’s true. But lambdas in Java or C++ haven’t yet materialized, and (in Java) perhaps never will. C# has these, but that’s only one out of 3. And macros: Never. No other language has such a meta-level of control with as little fuss as lisp.

By: Laurie

Laurie — Mon, 21 Jul 2008 14:33:51 +0000

Cory – fantastic analogy. It even explains why nobody uses Lisp:

“Unfortunately, although other languages can give you a beautiful, ergonomic wrench that’s well designed and pleasant to use, everything in Lisp has bobbles on top because it’s made out of lego bricks.”