Removing duplicate lists from a list of lists

Scripting Forums AppleScript | Mac OS X
#1

I’m trying to remove duplicate lists from a list of lists. (I’ve tried searching the forums but I have only found solutions for lists of strings, integers, etc. Those solutions don’t seem to work on a list of lists)

How would I remove duplicate items from a list such as the following:


set TheList to {{1, 2}, {3, 4}, {2, 2}, {1, 2}, {1, 1}, {3, 4}}
set TheList to RemoveDuplicates(TheList)
--> {{1, 2}, {3, 4}, {2, 2}, {1, 1}}


on RemoveDuplicates(TheList)

-- ??? what goes here ???

end RemoveDuplicates
#2

A very good explanation of lists within lists comparisons is found here. Look for the How to compare lists that contain sublists topic.

Utilizing that information, try this script:


set TheList to {{1, 2}, {3, 4}, {2, 2}, {1, 2}, {1, 1}, {3, 4}}
set TheList to RemoveDuplicates(TheList)
-->{{1, 2}, {3, 4}, {2, 2}, {1, 1}}

to RemoveDuplicates(TheList)
	set newList to {}
	repeat with a from 1 to (TheList's length)
		if newList does not contain {(TheList's item a)} then set end of newList to (TheList's item a)
	end repeat
	return newList
end RemoveDuplicates
#3

Thanks Craig

Your solution worked perfectly, and that link was very clear at explaining how lists of lists work.