Wednesday, November 22, 2006

Control Delimiters and Their Hierarchies

If you haven't heard, PLT has released DrScheme version 360.

See Jens Axel Søgaard's recent post for an exhaustive overview.

One of the exciting new features is that of prompts (or runs) and marks for call-with-continuation. To get a good introduction to these terms and what it brings to the table of your desktop DrScheme, please read Sitaram and Felleisen ( Lisp and Symbolic Computation ) Control Delimiters and Their Hierarchies , from 1990. That's right, we're just now realizing the foresight of these two academics, some sixteen years after they published. I've only browsed the paper once, but it really motivates me to tackle the new constructs we've been handed by the PLT team. Sometimes new constructs come to a language and everyone's excited for a while, but they just amount to syntactic sugar candy. What Sitaram and Felleisen proposed, and we now have implemented is most definitely not sugar candy.

Dorai Sitaram is author of the highly acclaimed introductory text on Scheme,

Teach Yourself Scheme in Fixnum Days, 1998-2004. If somehow you've stumbled upon this blog and want to know what all the fuss is about check it out online. Matthias Felleisen teaches at Northeastern, and his principle area of research is summed up by the title of a book for which he is first author, How to Design Programs, 2003. This is another excellent resource, not just for learning Scheme, but for learning the art of programming. For those of you, who like myself grew up writing c and then c++, you may prefer the K&R style taken by Kent Dybvig in his classic text, The Scheme Programming Language, 3rd ed., also available online. When I was a kid you actually had to go to a store and buy these things made principally of paper with pages, they called them books.

We'll be back on topic next posting. --kyle