Inside 206-105

Existential Pontification and Generalized Abstract Digressions

Compilers

No grammar? No problem!

One day, you’re strolling along fields of code, when suddenly you spot a syntax construct that you don’t understand. Perhaps you’d ask your desk-mate, who’d tell you in an instant what it was. Perhaps your programming toolchain can tell you. (Perhaps the IDE would you mouse over the construct, or you’re using Coq which let’s […]

The AST Typing Problem

This Lambda the Ultimate post (dated 2010) describes a rather universal problem faced by compiler writers: how does one go about adding “extra information” (e.g. types) to an AST? (The post itself divides the problem into three components: adding the information to the data types, using the information to inform the construction of the node, […]

Category theory for loop optimizations

Christopher de Sa and I have been working on a category theoretic approach to optimizing MapReduce-like pipelines. Actually, we didn’t start with any category theory—we were originally trying to impose some structure on some of the existing loop optimizations that the Delite compiler performed, and along the way, we rediscovered the rich relationship between category […]

Purpose of proof: semi-formal methods

In which the author muses that “semi-formal methods” (that is, non computer-assisted proof writing) should take a more active role in allowing software engineers to communicate with one another. C++0x has a lot of new, whiz-bang features in it, one of which is the atomic operations library. This library has advanced features that enable compiler […]

Data is Code

Yesterday I had the pleasure of attending a colloquium given by Chung-Chieh Shan on Embedding Probabilistic Languages. A full account for the talk can be found in this paper, so I want to focus in on one specific big idea: the idea that data is code. Lispers are well acquainted with the mantra, “code is […]