Archive for March 31, 2003

Monday, March 31, 2003

Continuations and VMs

Dan Sugalski:

Anyway, a continuation is essentially a closure that, in addition to closing over the lexical environment, also closes over the control chain. (Well, OK, control stack, but if you’re doing continuations odds are it’s a singly linked list rather than a real stack.) CS texts generally go on about continuations being “the rest of the program” or “gotos with arguments” or suchlike stuff. If those float your boat, great—they never made sense to me.

Yeah, I think it depends on whether you are looking at this from the angle of implementation or theory. If you’re writing a VM, then you think in terms of closing over the control chain. If you’re doing denotational semantics, you think in terms of lambdas for the rest of the program.

Update: Here’s part 2.

Open Source StackViews

Alexei Kosut:

So I rewrote this thing yet again. I didn’t use any of Omni or Camino’s code, although having seen their implementations did make mine go pretty quickly. And now I’m relatively happy, since my table-like view works, and the licensing works out the way I wanted. But still, it seems like there’s something wrong that there’s all that source code out there that does exactly what I want, and that I can even download and look at, but cannot use. Were I a more philosophical or political person, I might even have something Important to say about it.

IMO, this kind of view should really be part of Cocoa to begin with, as it is in Java.

Objective-C Code

Apparently there are archives of NeXT source code here and here.

Interview: Brent Simmons

John Gruber interviews Brent Simmons, the author of NetNewsWire.

Quote of the Day

I will now sell five copies of the Three EPs by The Beta Band.High Fidelity