AppleScript: The Definitive Guide, 2nd Edition

Chapter 22. Speed

There are people who worry about squeezing every last possible ounce of speed out of AppleScript. They like nothing better than to sit down with a script and find clever ways of rearranging or reexpressing it so as to make it run faster. They have developed ingenious tricks and devices to optimize AppleScript code for speed. They even hold little contests to see whose script can complete a given task fastest! Personally, I'm not a great believer in optimizing code, but it's certainly true, as a practical matter, that most AppleScript programmers, sooner or later, do become concerned about speed. You've developed a script, and it's working, but when it runs it's taking longer than you think it should. You want to know whether there's anything you can do to make your script faster.

A few general considerations will put speed into perspective:

Things are better than they used to be

AppleScript is a lot faster than it once was, not just because we're all using vastly quicker computers these days, but because the runtime engine has been made more efficient. AppleScript used to be downright sluggish, and this was very noticeable back in the old days when computers had floppy disk slots and less than 4MB of RAM (and we all had to clean the streets with our tongues on the way to school). That's no longer the case.

Interapplication communication is a bottleneck

AppleScript is all about communicating with other applications. It (AppleScript) isn't supposed to be fast, because ...