Podcasts

The strategy pattern lets you make "pluggable algorithms", so clients have different behavior without having different code themselves. We often use it to capture the "consequence in code" of some condition, which we can then let other code use without re-testing the condition. Here’s a little java snippet: dimension = horizontal ? width : height If you’re not familiar with ternary operations, what this says is "if horizontal is true, use the width, otherwise use the height". That snippet occurs […]

Another refactoring topic today: dealing with nulls. There are a bunch of techniques, but they amount to a) don’t, and b) do but only one time ever. The basic idea: a null always occurs in a particular context, and in that context, it has a meaning. When we pass it up or down our call-stack, we are changing contexts, and hence changing meanings. We’re using the same symbol to mean different things at different times. Using the same generic symbol

A key value for those who take up the change-harvesting approach: "keep it running". This is actually a direct result of human, local, oriented, taken, iterative, and argues against many finish-line efficiency approaches. Think of a change as a point A, with an arrow coming out of it and ending at a point B. At the two points, we have a running system, but along the arrow, we don’t: our change is in flight. The change-harvester seeks to keep those

In our continuing conversation about refactoring, I want to go a little abstract today, and talk about chunking and naming. Naturally, a topic thisi important has already been addressed by a stupid joke in the movie Airplane!, so we’ll start there. A passenger is approached by a steward, asking if he might be able to help with a problem in the cockpit. He says, "The cockpit! What is it?". She says, "It’s the little room at the front of the