Wednesday, July 26, 2006

The Zen of Hashing

Hashing and hash algorithms are a pet interest of mine. Understanding hashing at a low level takes a fair amount of meditation. Most programmers are too busy for that. Thus hashing is not well understood outside of, say, cryptography circles.

As it turns out, the guy who did the amusing boredom-graph cartoon (see yesterday's blog) also has written one of the best overviews of hashing I've seen in a long time. Be sure to see his excellent Hash Functions and Block Ciphers page as well.

Study the material on Bob's site. Save yourself years of meditation.

Tuesday, July 25, 2006

A Timeless Graph

Bob Jensen created this wonderful graph, which confirms what I've long thought: boredom tends to be continuous over its range.

Monday, July 17, 2006

Making XML Smaller

In all the hand-wringing discussions about XML's verbosity that I've read over the years, I have yet to hear anyone suggest simply truncating all closing tags to </>. In other words, if you've got


why not just shorten it to


Verbose closing tags are a pure waste of space (albeit required by XML spec). Abbreviated closing tags don't make the file any less parsable. When the parser encounters </> it knows that the closure is at the nesting level of the previous opening tag. If not, the XML was not well-formed to begin with.

Verbose closing tags are just that. Unneeded verbosity.