I forgot to mention that Scheme does have something that Common LISP doesn't. First class continuations. But I think they are a topic more suitable for an advanced programming languages class. However, it is certainly possible to program Common LISP in a continuation passing style despite the lack of call/cc.
P.S. - I've never used Lisp before, but I've used scheme, and I've heard they're similar. How close are they?
This depends on what you mean when you say "Lisp". If you mean the Lisp family of languages then the answer is that Scheme is a member of this family. Scheme's origins lie in a very old dialect of Lisp. In the widest sense of the term the Lisp family includes languages like Dylan and Python.
However, this is probably not what you meant. I take it that you are actually talking about ANSI Common LISP as described by ANSI X3.226-1994. In that respect the languages are very different. The Common LISP standard was created in an effort to pool the best parts of the various dialects in existence at the time (mid-1980s I think.) This included taking the most important advances made by Scheme (lexical scoping.) (Well, at least, what the designers of Common Lisp thought to be most important.)
The most important differences between Scheme and Common LISP are:
Scheme is a Lisp1 while Common Lisp is Lisp2. That is Scheme only has one namespace for all symbols. In Common LISP a symbol can stand for several things at the same time including a function name, variable name, class name, type name etc. What it actually stands for is determined by the context. The term Lisp2 is actully misleading since as you can see it has more than two namespaces. (I think the full number is around seven.)
Common Lisp has packages whereas Scheme. Packages map symbol names to symbols prevent name clashes between different libraries of code. This is much like Java.
Common LISP has very powerful exception handling. Better than Java in fact since the program can be restarted from the point where an exception was signalled.
Common LISP includes CLOS (Common LISP Object System.) A powerful OO programming extension intergrated with the type system. CLOS has generic functions, multi-methods, multiple-inheritance. It also supports dynamic class redefinition and usually comes with a MOP (MetaObject Protocol, a reflection and introspection API.)
Common LISP also has powerful macro system for arbitrary compile-time code transformations. A bit like C macros on steroids and hundred times more useful. Scheme has its own "hygienic macros" for similar purposes.
Its also the ASCII file format that worries me. If they only need to represent four code words (G, A, C, T) they could have used 2 bits (2^2 = 4) for each one rather than the ASCII 8 bits. This would take up only 1/4 of the space. Of course, this method doesn't take into account error correction and so on but then again, ASCII doesn't provide that either.
The GPL doesn't represent a particular development model at all. That's only what the "Open Source" movement would claim. In truth, the GPL represents a user's freedom when it comes to software. This is regardless of whether it was developed in the "Cathedral style" or the "Bazaar style."
Otherwise, I agree that the "GPL it" phrase is overused. People need to understand the reasons for why the GPL came about (ie. freedom) and apply those *ideals* to items other than software rather than just slapping a "GPL" label on them.
I had a look at the Pad++ just now. It looks promising, some real innovation at last. It also incorporates the idea of magic lenses. Unfortunately the implemenation is only available for non-commercial use.
However, the good news is that Jazz (a Java implementation of the zoomable UI) has just been made available under the Mozilla Public License. This is something worthy of more people's attention, IMHO.
They took all farms from the private hands (with or without the owners consent) and turned them into megafarms producing food that was shared amongst those who worked on them and the surplus (if any) would be sold to the shops. Eventually they 'phased out' private ownership altogether.
I think this comparison is flawed. The GPL doesn't force anyone to hand over their code. And once you've joined the so-called Free Software community no one can stop you from leaving. You are also not prevented from writing proprietary software at the same time (as long as you don't mix the two.)
However, once you release something under the GPL you can't then go back and make it proprietary. This is similar to writing code for an employer (lets say a corporation in the capitalist sense.) If you've chosen to write some code for them in exchange for money you cannot come back to them later and claim that the code belongs exclusively to you.
Slashdot Mirror
-- Peter
This depends on what you mean when you say "Lisp". If you mean the Lisp family of languages then the answer is that Scheme is a member of this family. Scheme's origins lie in a very old dialect of Lisp. In the widest sense of the term the Lisp family includes languages like Dylan and Python.
However, this is probably not what you meant. I take it that you are actually talking about ANSI Common LISP as described by ANSI X3.226-1994. In that respect the languages are very different. The Common LISP standard was created in an effort to pool the best parts of the various dialects in existence at the time (mid-1980s I think.) This included taking the most important advances made by Scheme (lexical scoping.) (Well, at least, what the designers of Common Lisp thought to be most important.)
The most important differences between Scheme and Common LISP are:
Scheme is a Lisp1 while Common Lisp is Lisp2. That is Scheme only has one namespace for all symbols. In Common LISP a symbol can stand for several things at the same time including a function name, variable name, class name, type name etc. What it actually stands for is determined by the context. The term Lisp2 is actully misleading since as you can see it has more than two namespaces. (I think the full number is around seven.)
Common Lisp has packages whereas Scheme. Packages map symbol names to symbols prevent name clashes between different libraries of code. This is much like Java.
Common LISP has very powerful exception handling. Better than Java in fact since the program can be restarted from the point where an exception was signalled.
Common LISP includes CLOS (Common LISP Object System.) A powerful OO programming extension intergrated with the type system. CLOS has generic functions, multi-methods, multiple-inheritance. It also supports dynamic class redefinition and usually comes with a MOP (MetaObject Protocol, a reflection and introspection API.)
Common LISP also has powerful macro system for arbitrary compile-time code transformations. A bit like C macros on steroids and hundred times more useful. Scheme has its own "hygienic macros" for similar purposes.
Scheme lacks CLOS, packages and exceptions.
Anyway, I hope this helps.
-- Peter
Its also the ASCII file format that worries me. If they only need to represent four code words (G, A, C, T) they could have used 2 bits (2^2 = 4) for each one rather than the ASCII 8 bits. This would take up only 1/4 of the space. Of course, this method doesn't take into account error correction and so on but then again, ASCII doesn't provide that either.
Otherwise, I agree that the "GPL it" phrase is overused. People need to understand the reasons for why the GPL came about (ie. freedom) and apply those *ideals* to items other than software rather than just slapping a "GPL" label on them.
However, the good news is that Jazz (a Java implementation of the zoomable UI) has just been made available under the Mozilla Public License. This is something worthy of more people's attention, IMHO.
I think this comparison is flawed. The GPL doesn't force anyone to hand over their code. And once you've joined the so-called Free Software community no one can stop you from leaving. You are also not prevented from writing proprietary software at the same time (as long as you don't mix the two.)
However, once you release something under the GPL you can't then go back and make it proprietary. This is similar to writing code for an employer (lets say a corporation in the capitalist sense.) If you've chosen to write some code for them in exchange for money you cannot come back to them later and claim that the code belongs exclusively to you.
Also check out the HUGO Interactive Fiction Design System.
There is a version of Zork for it but i can't remember where exactly i found it. I suggest searching around the site.