In most situations I would agree.... However, in this case the problem space was clearly defined and the question is a valid one in my opinion. The question was something like:

"I want to replace all occurances of '.' with '/' in a string. I know that there are at least two ways to do this (s/// and tr///). Which one is faster?"

Now perhaps one could argue that "faster" should be replaced with something a bit more encompassing (better, 'the right choice', etc), but in the end what really is the difference between s|\.|/|g and tr|\.|/|?

What if the question had been:

"I'd like to grab the last character in a string. I know there are at least two ways to do this (split '',$txt)[-1] and substr($txt,-1). Which one is faster?"

Would it still be considered premature optimization to suggest that substr is the correct answer?

In both questions there is a solution that uses a slower general tool (regex, split) and one with a faster specialized tool (tr///, substr). If you aren't going to use the specialized tools in these cases, when are you *ever* going to use them?

Oh, and I posted some benchmarks a while back showing tr/// running about 15 times faster that s/// for a particular case...

Update: virtualsue has brought to my attention that her "premature optimization" statement was about running benchmarks for small insignificant parts of a program. She wasn't advocating s/// over tr/// in this case, simply stating that benchmarking the two was a poor use of human cycles. To that I wholehartedly agree... I seem to have read the node slightly out of context, and get a little touchy when I see people using elephant guns (s///) when a well designed flyswatter (tr///) would do.

-Blake

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