Nomic is a game created in 1982 by philosopher Peter Suber in which the rules of the game include mechanisms for the players to change those rules, usually beginning through a system of democratic voting.

When a message is sent to a Smalltalk-80 object, the method dictionaries associated with that object's class and its superclasses are searched at runtime. If none of these classes implement a method for a given message, the Smalltalk virtual machine sends the object the message doesNotUnderstand:. The original message selector and message arguments are bundled together in a Message object and passed as the argument to doesNotUnderstand:. The default method for this message is stored in class Object. This method invokes the Smalltalk debugger, since sending an object a message it does not implement is usually a sign of programmer error. However, objects that override doesNotUnderstand: can intercept unimplemented message at runtime, and process them as they see fit.

Implementation inheritance... is a bad idea that makes software harder to manage and reuse. It binds the implementations of classes together so that neither class can be understood without the other: a subclass cannot be understood without knowing how the inherited methods are implemented in its superclass, and a superclass cannot be understood without knowing how its methods are inherited in subclasses. In a complex class hierarchy, no individual class can be understood without understanding all the other classes in the hierarchy.

Nonetheless, object oriented programming does provide at least two useful features. The first is encapsulation: objects combine together data and code in a way that hides implementation details. The second useful feature is interface inheritance, which refers to classes that provide the same methods and APIs even though they have different implementations. This makes the classes interchangeable, which encourages reuse.

Arrowlets is a JavaScript library that uses the concept of arrows to make the task of composing event-handlers easy. Event handlers are written as normal functions, as you would today, and Arrowlets provide flexible combinators to easily compose sequence of events, animation, asynchronous network access, and making long-running computations while keeping the UI responsive.

Wow. Promises are a polymorphic equi-recursive abstract structural type encoding a monadic style of asynchronous programming. In JavaScript.

Semantically, Events can be thought of as lists of time/value pairs where the times are non-decreasing

The canonical solution for determining the sign of a zero is to divide one by it and then check whether the result is -Infinity or +Infinity

Denial that the expression problem exists is a common symptom of overzealous functional or object-oriented dogmatism.

How can we design systems when we don't know what we're doing?

The most exciting engineering challenges lie on the boundary of theory and the unknown. Not so unknown that they're hopeless, but not enough theory to predict the results of our decisions. Systems at this boundary often rely on emergent behavior — high-level effects that arise indirectly from low-level interactions.

When designing at this boundary, the challenge lies not in constructing the system, but in understanding it. In the absence of theory, we must develop an intuition to guide our decisions. The design process is thus one of exploration and discovery.

As of February 2012 I’m writing a book for O’Reilly Media. Its working title is “Understanding Computation”.

It’s a book about old, deep ideas from theoretical computer science, deconstructed and explained in an engaging, practical way for an audience of working programmers.

Mitchell's best-candidate algorithm generates a new random sample by creating k candidate samples, and picking the best of k. Here the "best" sample is defined as the sample that is farthest away from previous samples.