This article reviews the good theory: regular expressions, finite automata, and a regular expression search algorithm invented by Ken Thompson in the mid-1960s. It also puts the theory into practice, describing a simple implementation of Thompson's algorithm. That implementation, less than 400 lines of C, is the one that went head to head with Perl above. It outperforms the more complex real-world implementations used by Perl, Python, PCRE, and others. The article concludes with a discussion of how theory might yet be converted into practice in the real-world implementations.

We describe a new language called Pig Latin that we have designed to fit in a sweet spot between the declarative style of SQL, and the low-level, procedural style of map-reduce.

With the availability of Visual C++ .NET, Microsoft recommended and condoned deploying its CRT as a private DLL, simply a file in the directory of installed program. However, this stance of private deployment is no longer suitable or advisable in our modern world. As we have learned all too well since 2002 and especially from Microsoft’s embarrassing tool to patch a buggy gdiplus.dll across the system, deploying high profile DLLs privately does not allow for central servicing.

Signals and slots are a refinement of the Observer Pattern, a powerful metaphor, and a great tool for assembling software from components. They've been a part of the computer science landscape for over a decade, and many mature implementations exist.

A nexus is a tree that contains shared nodes, nodes that have more than one incoming arc. Shared nodes are created in almost every functional program—for instance, when updating a purely func- tional data structure—though programmers are seldom aware of this. In fact, there are only a few algorithms that exploit sharing of nodes consciously. One example is constructing a tree in sublinear time. In this pearl we discuss an intriguing application of nexuses; we show that they serve admirably as memo structures featuring constant time access to memoized function calls. Along the way we encounter Boolean lattices and binomial trees.

The existing model of functional programming, although elegant and powerful, is compromised to a greater extent than is commonly recognised by the presence of partial functions. We consider a simple discipline of total functional programming designed to exclude the possibility of non-termination. Among other things this requires a type distinction between data, which is finite, and codata, which is potentially infinite.

Brian recently posted an article comparing UUID and auto_increment primary keys, basically advertising to use UUID instead of primary keys. I wanted to clarify this a bit as I’ve seen it being problems in so many cases.

Reverse enginering of Skype.

Tail-recursive schemy iteration is too low-level and, according to Olin, a higher-level abstraction hiding details and providing a modular interface and proper lexical scope is called for. In his presentation, he outlines his solution to this problem, which, as you will see, amounts to defining a looping domain-specific language (actually, a couple of them).

We present data collected from detailed observations of a large disk drive population in a production Internet services de- ployment. The population observed is many times larger than that of previous studies. In addition to presenting failure statis- tics, we analyze the correlation between failures and several parameters generally believed to impact longevity.