I read the article in question, and it said that marijuana didn't have much effect on "chronic" marijuana users. I suspect that if you smoke pot occasionally, it will totally destroy your programming ability while high.

You need to look at this study carefully. Essentially, it says if you are a pothead, pot smoking isn't so bad for your cognitive skills. But, that isn't to say that the long term effects of pot didn't already impair you... it just means that once you are used to it, it doesn't hurt you to be smoking it.

The article makes perfect sense really. There is certainly such a thing as a "high-functioning alcoholic." That doesn't mean anyone can get drunk and work well, or that alcohol helps you work. It just means alcoholics have a tolerance.