archives

Linking comments

It'd be nice if there were a convenient way to link directly to a comment, i.e. have the comment titles be links to themselves or perhaps a small icon beside them. The anchors are there as the following link demonstrates, but the only way to get at them is by searching for the comment or constructing the link yourself (or at least those were the only ways I could find after a bit of trying).

http://lambda-the-ultimate.org/node/view/100#comment-873

[Edit: You can also get the links in collapsed views, but still...]

Guido: Adding Optional Static Typing to Python -- Part II

Part II (see Part I discussion on LtU).

Among the notions discussed: Interfaces and Design By Contract, Parameterized Types and Types vs. Classes.

Composable memory transactions

Composable memory transactions. Tim Harris, Simon Marlow, Simon Peyton Jones, and Maurice Herlihy. Submitted to PPoPP 2005.

Writing concurrent programs is notoriously difficult, and is of increasing practical importance. A particular source of concern is that even correctly-implemented concurrency abstractions cannot be composed together to form larger abstractions. In this paper we present a new concurrency model, based on transactional memory, that offers far richer composition. All the usual benefits of transactional memory are present (e.g. freedom from deadlock), but in addition we describe new modular forms of blocking and choice that have been inaccessible in earlier work.

The work is in the context of Concurrent Haskell (of course). The authors work from the assumption that a purely functional (they use the term declarative) language is a perfect setting for transactional memory. The reason is that mutable state is rare and explicit.

Links (Wadler)

Wonder what Wadler is up to?
My latest research interest is a programming language for web application development, building on my experience with XML, Java, and Haskell.

A short introduction and a set of slides are available (both PDF).

Wonder about the language name?

A quarter of a century ago, Burstall and others at Edinburgh introduced an influential programming language, Hope, named after Hope Park Square, located near the University on the Meadows. This note proposes a research effort to design a new programming language for the web, Links, named after the Brunts-field Links, located at the other end of the the Meadows and site of the world’s first public golf course.

And here's why you should be interested in this work,

Other languages for web programming include Xtatic from Pierce, Scala from Odersky, and Xen and Cw from Microsoft. Links will benefit from fruitful interactions with these efforts. However, Links differs crucially in that it adopts database ideas from Kleisli and systems principles from Erlang, taking it well beyond the capabilities of these other languages.