Author: grant

The Soundex Algorithm

Soundex is a phonetic algorithm for indexing names by sound, as pronounced in English. The goal is for names with the same pronunciation to be encoded to the same representation so that they can be matched despite minor differences in spelling[1]. Soundex is the most widely known of all phonetic algorithms and is often used (incorrectly) as a synonym for “phonetic algorithm”. Improvements to Soundex are the basis for many modern phonetic algorithms

— Wikipedia Entry
(via Vijay Matthew)

Computers are a metamedium

The computer is a medium that can dynamically simulate the details of any other medium, including media that cannot exist physically. It is not a tool, although it can act like many tools. The computer is the first metamedium, and as such it has degrees of freedom for representation and expression never before encountered and as yet barely investigated. The protean nature of the computer is such that it can act like a machine or like a language to be shaped and exploited.

— Alan Kay
I’ve never before heard it put quite so well.
(via R.P. James)

Easy FTP mirroring with wget

There are a lot of tools out there for mirroring data, but sometimes you just want to do something very simple: download the latest contents of a FTP directory while leaving what you have already downloaded alone. wget supports a mirror command that provides this exact functionality. Just enter the directory where you would like to store the mirror and execute this command:

wget --mirror [prot]://[username]:[password]@[hostname]/[directory to mirror]

Lisp Style Rules

Riastradh’s Lisp Style Rules are a wholly holistic and unscientific take on Lisp style rules. They have helped me not only to get a better sense of how Lisp people do things, but also why. There is other stuff like this around the Internet, but this is the only I’ve found that I enjoyed reading.
While there are a lot of good rules in the guide, not all of them were new to me, so I only took notes on the ones that I found interesting for one reason or another.
Continue reading “Lisp Style Rules”

GNU Emacs on Cygwin

While it is possible to run Emacs on Windows, I suspect that Emacs “expects” to be running on UNIX. As such, I’ve decided to perform an experiment and try to do most of my work in Cygwin, including running Emacs. The following is how I did it:
Steps

  1. Create a Windows environment variable named ‘CYGWIN’ with the value ‘tty’
  2. Install Cygwin
  3. Install Cygwin/X
  4. Download-and-install Emacs using the setup.exe (as explained in the documentation linked above), choose the packages ’emacs’ and ’emacs-X11′, and be sure to check the “Bin?” checkbox. If you don’t check “Bin?” it will look like the installer is doing something, but in reality it does nothing (guess how I know that?).
  5. Add this to your .bashrc (see steps below if you want to use Emacs): export DISPLAY=:0.0
  6. Run: source .bashrc
  7. Run: XWin -multiwindow &
  8. Run: xeyes &
  9. Xeyes should pop up. Now try emacs
  10. Run: emacs &
  11. The Emacs welcome screen should appear.

Updating your .bashrc

  1. Open a terminal
  2. Type: emacs -nw .bashrc
  3. Emacs gives you a welcome message. Hit C-l to continue editing.
  4. Go to the bottom of the page
  5. Insert an empty line at the end and type in the text listed above
  6. Hit C-x C-s to save the file
  7. Hit C-x C-c to exit Emacs

References

Addendum: 16/10/08
I removed the unnecessarily complex step re-starting the shell when source’ing would have done just fine.
I wasn’t happy with my explanation for doing this, so I revised it.

Computer Science Teachers Association

The Computer Science Teachers Association is a membership organization that supports and promotes the teaching of computer science and other computing disciplines. CSTA provides opportunities for K-12 teachers and students to better understand the computing disciplines and to more successfully prepare themselves to teach and learn.