Primate Parts

Recently Chris Lamb and friends wrote about their experience adding a feature to javac, a pastime slightly more popular than it used to be now that javac's sources have been opened under the GPL. And he found something strange:

"Anyway, it turns out that the javacc [sic] code is messy. Really really messy. But it’s the source of great amusement though, not only from the scary amount of no-op casts, misleading indenting and undocumented functions, but the lexical token for the ‘@‘ symbol is ‘MONKEYS_AT‘. No, we have no idea either."

I responded with a conditional promise to tell him the story:

"Actually, the indentation is consistent if you have your tabs set at 8 spaces, where God intended them.
"There’s a story behind MONKEYS_AT, and if you know it this little piece of code is a funny inside joke. But if you want me to tell you, you’ll have to take back your assertion that javac’s code is messy and tell me that it’s a work of art."

Chris quickly buckled to the pressure, responding by email:

"Yes, it is true - when set it to 8 spaces, it seems to look a bit
better. What I mean to say is, it's now a work of art and any blemishes
are my fault. :)

"Anyway, yes, my friends and I would really like to know this story
behind the naming of the token though -- we found it at about 3AM whilst
hacking on the javac code and it put us off our stride somewhat. ^_^"

Here's the formerly untold story of MONKEYS_AT.

During the development of the JDK5 language features, the Sun team had regular meetings with a team from Denmark that was designing and implementing the variance feature (since renamed wildcards, which is a longer and more interesting story).  You can find the team member names in the paper describing the work. The Danish team was led by Mads Torgersen, and we all enjoyed a number of evenings chatting over beer. During one such session, I was discussing the work I was doing to implement annotations, and I mentioned that, unlike the "#" character that seems to have many names, there don't seem to be any alternative names for the "@" character. Mads told us that in Denmark, there are a number of names for this character, including the archaic "monkey's ass", which refers to the similarity in appearance of this character to the rear end of a monkey. We all thought this was hilarious, but perhaps a bit too risque to put in corporate-developed and publicly-visible sources. But it was just too funny to leave out. Thus I came up with the pun MONKEYS_AT. To this day that little inside joke in the sources reminds me of the team and the time we spent together.

Mads, by the way, is the one on the left. ;-)
There you have it: a disinterested observer, inclined to believe otherwise, comes to appreciate the beauty and humor of javac.