Alright. I''ve spent about a month working on clisp- writing various functions, mostly dealing with string handling and analyzing. I have experienced no evidence that clisp provides any superiority relative to my personal favorite imperative language, C++. It of course provides better facilities here and there; however, I see no advantage compared to a well-written imperative library. Could I please see a clear, obvious example where the lisp paradigm makes programming a solution easier? I''m not trying to make a c++ vs. lisp war, so no flames. I''d just like a well-written example or two, or even a link to one. Thanks alot. ~V''lion Bugle4d

I could see a few reasons why Lisp is superior to other development platforms in application development due to code is data and data is code paradigm. If you''re interested dig up an old Lisp vs. XML thread. This superiority is minimized with recent advancements in .NET where classes are easily serialized into XML and back, and source code is generated from XML schema in a few seconds. Of course theoretically Lisp is still more powerful but practically .NET platform provides everything you need to successfully do data parsing, serialization and storage.

I do not see how Lisp would be superior specifically for AI. Of course I''m not a Lisp expert (I never wrote more than a few lines of code in it). May be someone else can give you a more qualified response.

Have you read What is so great about Lisp? and Lisp is King? They both contain a lot of information. Yes they are long, but if you haven''t read them I think it would be worth it to do so.

quote:Original post by Extrarius
Have you read What is so great about Lisp? and Lisp is King? They both contain a lot of information. Yes they are long, but if you haven''t read them I think it would be worth it to do so.

I''ll second that. Very good threads.

quote:Very. The C++ paradigm has taught you to work within its own limitations. You must explicitly define the exact structure of a class or struct and then work with it. Lisp doesn''t impose this on you. Lisp works well with incomplete data, or data structures which grow according to the evolving data that is being acquired.

From Lisp is King thread.

The last sentence illustrates a common thing I''ve heard WRT lisp- its flexibility.

Could I see some hard code here regarding that? Its a pretty thing to say, but due to my inexperience, I don''t perceive how to do that in clisp.

Anyway:
I still don''t see why lisp is conclusively better than a well-written imperative langauge with a good library behind it.
I''ve even looked through a goodly portion of On Lisp and don''t see why.

~V''lion

Bugle4d

Really, I can''t think of any examples that would show how flexable lisp is without being complete programs. It is very difficult to find trivial examples that really demonstrate how usefull features can be =-/
First, realize that Common Lisp is NOT the best language at everything (nor is any other language). There are some things, such as systems programming (drivers, OSes, etc) that are possible but not easily or best done in Lisp. Common Lisp is a good general purpose langauge that allows you to focus on more abstract things than byte alignment and calling conventions. While it isn''t as fast as native-compiled C++, it is close, and definitely fast enough for many, if not all, games and other real-time applications. Note that the speed depends quite heavily on which compiler you use. I don''t know about clisp (it might even be only an interpreter), but Corman''s compiler is quite good and makes fast code (an absolute measurement, I don''t have anything to compare it to).

The best example of flexibility I can think of (probably because its the only thing I''ve used Lisp for so far) is genetic programming. In C++ or some other low-level language, creating a genetic programming library would either require all kinds of trickery with assembly and manually managing the calling conventions of functions OR implementing an interpreter. In Lisp, you can just use the list functions to make a list, (optionally) compile it at runtime, and then execute it as if it had always been there. Since Lisp code is represented as a list, and Lisp (LISt Processing) is good at manipulating lists, it is also quite easy to manipulate code. I haven''t quite finished my implementation of GA yet so I don''t have much code to post, but it took me about 1 day to get a basic code generator up and running and spitting out random formulas with next to no Lisp knowledge (most of the time was spent looking up things in ''ANSI Common Lisp'' because I didn''t know the language at all =-). In that time, I wrote ~100 lines of code that can create a random numerical expression and have it ready to be executed. The operators allowed in the expression, the number of arguments each takes, and the variables the function operates on are all customizable by a few global variables. The only reason I haven''t finished it is because I''ve moved on to making my own Lisp interpreter (which turned out to be a lot harder than I thought it would).

Since you like C++ you may also appreciate OOP. It''s interesting that the Common Lisp object system (CLOS) was not created by heavily modifying the Lisp language (or modifying it at all actually). Instead, it was added as a sort of library, as an embedded language. You cannot even begin to imagine some such wizardry in the C based crowd of languages.

Lisp changes the way you think. It''s a very slow process, but it is real. No longer do you ask yourself "what is the best way to use this language to solve this problem?", but "what is the best language to solve this problem?". You stop being a slave of a single language, of its particular way of thinking and of the limited things you can express in that language - instead each language gives you ideas of things you can say in Lisp. Prolog, CLIPS, GPSS or XML Schema - all look at programming in different ways - but you can have their philosophies directly imported in Lisp.

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Pax Solaris