Wilcox Development Solutions Blog

Fun AppleScript Tricks (or not)

September 24, 2003

Take a look at the following Applescript. What do you expect to happen in both cases?

Snippet #1

`

set ab to {“a”, “b”} set alpha to {“a”, “b”, “c”, “d”}

if ab is in alpha then log (“ab in alpha”) else log (“ab not in alpha”) end if`

Snippet #2

`

set ab to {“a”, “c”} set alpha to {“a”, “b”, “c”, “d”}

if ab is in alpha then log (“ab in alpha”) else log (“ab not in alpha”) end if`

Click below for the answer to the riddle Guessed it?

Snippet #1 will return “ab in alpha”, while snippet #2 will return “ab not in alpha”.

With this construct we are not asking “are these two items in the list, good sir?”, we are asking “are these two items in the list together, sir?”

To put it politely, that was unexpected. At least to me.

I tried to do a “are any of the list items from this one list in this other list” in Python, and it won’t let me (runtime error). I have to compare each object from list A to see if it’s list B. In one way, this feels somewhat dumb - in another way, this avoids the whole situation together.

So, like Python, I’m writing a loop in Applescript to do the compare. But I wasted at least 15 minutes more time than I should have on figuring out that the whole thing doesn’t work.

You have been warned. I wish I would have been.


Written by Ryan Wilcox Chief Developer, Wilcox Development Solutions... and other things