Category: Link

On Python and Lisp

The last time I spoke to a friend of mine who knows both Scheme and Common Lisp (among many other programming languages), his current language of choice was Python. More or less, he said that it just “feels right” (I need to pick his brain more on this).
Is Lisp the future of Python? Do Lispers gravitate towards Python? I’m not sure yet, but this paper aims to shed some light on both of those questions.

When Code Really is Art

For all of the programmers who lament the fact that code is not recognized as art, there is Piet.
Joking aside, once you get up to speed on stack based programming, this looks like a fun interpreter project. I am supposing that there are some very interesting opportunities on how to literally make your code “more beautiful”!
Addendum: 09/08/08
Here is a hello world program with a thorough walk-through and explanation of how it works.
Addendum: 12/28/08
Possible projects:

  • An interpreter
  • A picture editor
  • A graphical representation of the interpreter
  • A Scheme to Piet compiler; trained to generate “pretty pictures”

Mr Ed Designer: Generating User Interfaces with PLT Scheme

PLT Scheme’s user interface library is called Mr Ed. It is used to provide DrScheme to thousands of computers running Windows, Mac OS, and UNIX. It “just works”, and does so well; it is a fine graphics toolkit. MrEd Designer aims to make Mr Ed even easier to use!
Addendum: 7/14/8:
Peter Ivanyi now maintains this application.
Addendum: 09/10/08:
MrEd Designer 2.1.2 is released; it now supports tab-panels.
Addendum: 09/20/08
In MrEd Designer 2.1.3:

  • tooltips are added for the main buttons
  • the no-border style for the tab-panels is fixed.

Caveats of Object Creation using Closures

At one time or another you have probably heard the claim made that since you can utilize closures while programming in Lisp, there is no need to utilize an object system. That claim is sort of a half-truth. While closures are the language construct that allow you to create objects, they certainly don’t provide you with all of the object oriented programming language features that you would expect. Instead, you need to implement those features yourself.
The question was posed on the PLT discussion list. Some very good points were made about the issues you must address when implementing such an object system yourself, along with a pointer detailing how the issues are addressed in PLT Scheme.

Type Conversion with Eiffel

If you are going to utilize the Object Oriented paradigm for implementing your system, you ought to do yourself a favor and learn the Eiffel programming language. Why?
Take all of the things that are not included in your statically-typed OO language of choice because they are “too hard to understand”, and visit them in Eiffel. Not only does it have all of those features, but it makes them easy both to understand and utilize.
Read about type conversion, for example. What a wonderful language feature. You can even use tuples!
You will be left scratching your head, wondering why no one else has features like this (among many others).
Eiffel is really a gem of a language!

Nonstandard Interpretation with Scheme

In response to this excellent blog post by Dave Herman, Jay McCarthy pointed the reader to this interesting paper about creating a language construct that allows you to modularly redefine how your code (that you may or may not have written) gets evaluated (in other words, nonstandard interpretation).
Nonstandard interpretation

is a powerful and useful construct that supports such tasks as tracing, security logging, sandboxing, error checking, profiling, code instrumentation and metering, run-time code patching, and resource monitoring.

Obviously, these things aren’t new features. You can probably already perform nonstandard interpretation using your language of choice.
The interesting thing about this approach is that rather than performing compile time environment or code manipulation, a new language feature is applied to perform the non standard interpretation at runtime.
While both will get you to the place that you want to go; only the latter offers you an opportunity to build a conceptual framework for understand how you reached your destination. Neat!

Distributed Programming in Scheme

Here are two places to start with distributed programming in Scheme:
Termite
Dimitris Vyzovitis’s patch for revision 8983 (of trunk) in PLT Scheme
Addendum 03/21/08

  • Dimitris’ patch for additional mailbox functionality.

Addendum 04/26/08

Addendum 06/24/08
I’m pretty sure this patch has made it into the main source branch.