AppleScript: The Definitive Guide, 2nd Edition

Nonsensical Apple Events

As we saw in a previous section ("Compile-time Error"), AppleScript will sometimes blow the whistle at compile time to indicate that you are using a term as the wrong "part of speech." This is extremely helpful. For example, you can't use a verb as a noun:

tell application "Finder"
    get name of eject -- compile-time error: Expected expression but found command name
end tell

And you can't assign to a class:

tell application "Finder"
    set container to "howdy"
    -- compile-time error: Can't set «class ctnr» to "howdy". Access not allowed
end tell

You have to supply valid parameter names:

tell application "Finder"
    duplicate x by y -- compile-time error: Expected end of line but found "by"
end tell

The duplicate command doesn't have a by parameter, and the compiler knows this.

You can't make an element specifier out of something that isn't a class name:

tell application "Finder"
    get name 1 -- compile-time error: Expected end of line but found number
end tell

The compiler also displays some intelligence about singular and plural forms of a class name. The plural form of a class name is taken to be a synonym for the every element specifier; otherwise, if you use a plural where a singular is expected or vice versa, the compiler will usually change it for you, silently:

tell application "Finder"
    folder -- folder (the class name)
    folders -- {...}, a list of references to every folder
    folders 1 -- compiles as folder 1
    folder 1 thru 2 -- compiles as folders 1 thru 2
end tell

This ...