Build Systems à la Carte

Many programmers of my generation learned how to design software by reading the trilogy of books that Kernighan and colleagues wrote in the early days of Unix: The Elements of Programming Style, Software Tools in Pascal, and The Unix Programming Environment Kernighan1979,Kernighan1981,Kernighan1983. They showed us how to write readable programs and build the tools we ourselves used, and by doing so, helped us see the world of programming in a particular way.

Mokhov2018 is very much in that spirit. Its authors do a deep dive into one topic—build systems—and show how a variety of existing systems can be reconstructed by answering two questions that turn out to be independent of each other: which tasks are executed and in what order? To make their discussion concrete, Mokhov et al build a small framework in Haskell that allows different choices on these two axes to be mixed and matched. Doing this enables them to be very precise about what claims like "correctness" actually mean for a tool of this kind, though at the cost of readability for anyone who isn't familiar with the language.

I wish there were many more papers like this one. Rational reconstructions of existing tools within a single generalized explanatory framework allows us to make sense of what we've done and figure out what we might do next. If we are ever going to have a useful theory of software architecture, I believe it's going to come out of work like this.