Apple

I was just going to ask "Also, is AS able to call a handler on itself ?" when I checked the web, and...

Let's actually provide the code for people to chew on and so it can be found when searching the archives.

From Matt Neuburg's book AppleScript: The Definitive Guide, 2nd Edition

** NOTE the built-in AppleScript filter-form I've added.

------------------------------------------------------------------------------

# Auth: Christopher Stone (refactored from a handler by Matt Neuburg)

# dCre: 2017/04/14 11:49

# dMod: 2017/04/14 11:58

# Appl: Miscellaneous

# Task: Recursive Handler for filtering Numbers.

# Libs: None

# Osax: None

# Tags: @Applescript, @Script, @List, @Manipulate, @Recursive, @Recursion, @Handler, @Filter, @Numbers

------------------------------------------------------------------------------

set theList to {"hey", 1, "ho", 2, 3}

set filteredList1 to filterNumbers(theList) -- handler

set filteredList2 to numbers of theList -- built-in AppleScript filter form

------------------------------------------------------------------------------

--» HANDLERS

------------------------------------------------------------------------------

on filterNumbers(theList)

if theList = {} then return theList

if {class of item 1 of theList} is in {real, integer, number} then

return {item 1 of theList} & (filterNumbers(rest of theList))

else

return filterNumbers(rest of theList)

end if

end filterNumbers

------------------------------------------------------------------------------

And I also found CAR: item 1 of list and CDR: rest of list

For people not familiar with LISP functions:

CAR — takes a list as argument, and returns its first element.

CDR – takes a list as argument, and returns a list without the first element.

Don't forget positive and negative indexing.

set theList to {"one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"}

set newList1 to items 2 thru 4 of theList

set newList2 to items -3 thru -1 of theList

set newList3 to items 2 thru -1 of theList -- equivalent to “rest of”

References:
	>list manipulation (From: Jean-Christophe Helary <email@hidden>)