AppleScript: The Definitive Guide, 2nd Edition

Script Text File

A script text file is exactly that: it's an ordinary text file, such as can be opened by any word processor, consisting of the uncompiled text of your script. Any script editor application will typically offer an option for saving a script as text. No bytecode is saved into the file, and the script need not be capable of compilation in order to be saved as text—as opposed to a compiled script file , which by definition can't be saved unless the script can be compiled. (Apple's Script Editor does also attempt to compile the script when you save it as text, and will report any compilation errors even though saving succeded; this seems like a bug.) The conventional extension for a script text file on Mac OS X is .applescript, but it is still of type 'TEXT'.

Most script runners will refuse to execute a script text file; they generally expect a compiled script file, whereas a script text file is not compiled (and the script runner is not willing to do the compilation).

A script text file is described by Apple's documentation as a kind of low-grade, last-resort alternative to a compiled script file. But it does have certain advantages. For one thing, obviously, you can save it even though you can't compile the script, so if you're developing a script that won't compile or that you'd rather not compile just now, you have a way to save it. Also there are matters of compatibility and portability. Recall that Apple's Script Editor can't create a compiled script file that will ...