John Carmack discusses the art and science of software engineering

To link that back to the post, this is the type of constriction he's talking about to make better programmers. Cocoa and Objective-C restricted me to only writing at least halfway decent code. With PHP, because of it's flexibility, you're free to get things done quickly, but in a terrible way. Sure with PHP you can do things right too, but it takes a lot more self-discipline and also a priori knowledge.

Sorry to post yet another rag on PHP.

Why would you encounter this (often)? It seems to me that this code would never evaluate to true.

I wonder how many non-developers understand this. I, along with the rest of my team, am trained in PSP (http://www.sei.cmu.edu/library/abstracts/reports/00tr022.cfm) and TSP (http://www.sei.cmu.edu/tsp/) and we use it in our day-to-day development.

It definitely helps us keep our defect rate below one bug/kLOC but it's an expensive process that results in very low LOC/day productivity. If very low shipped bug counts are very important to your organization, great. But most businesses these days seem to care more about having a usable product than they do a perfect (or close to it) product. Especially if it's on the Web where you can do multiple releases per day.

As an industry, we really need to bear in mind that different business domains need radically different approaches to software engineering.

> if (obj != null && obj.isValid()) { }

Which is semantically correct due to the fail-fast evaluate of AND, it does require a double check since it's strange from a logic point of view. This is one the reasons that brace languages are hard to optimize since you can't commute things that ought to commute.

"We could, of course, use any notation we want; do not laugh at notations; invent them, they are powerful. In fact, mathematics is, to a large extent, invention of better notations. The whole idea of a four-vector, in fact, is an improvement in notation so that the transformations can be remembered easily."

What he said about mathematics, I think it applies even more to programming.

[1] The Feynman Lecture on Physics, Volume 1, Chapter 17