Finding element in list and getting offset

LiveCode Builder is a language for extending LiveCode's capabilities, creating new object types as Widgets, and libraries that access lower-level APIs in OSes, applications, and DLLs.

Moderators: LCMark, LCfraser

Post Reply
trevordevore
VIP Livecode Opensource Backer
VIP Livecode Opensource Backer
Posts: 1005
Joined: Sat Apr 08, 2006 3:06 pm
Location: Overland Park, Kansas
Contact:

Finding element in list and getting offset

Post by trevordevore » Wed Feb 18, 2015 5:41 am

I'm searching a list for a matching element. I see that there is syntax for determining if an element is found in a list, but no syntax that returns the element number of the element in the list. Does the syntax exist and I just don't see it documented? Or is this an oversight? Or is it not really needed?

Here is my workaround:

Code: Select all

variable tElement as string
  repeat with tElement from 1 up to the number of elements in mTags
		if pTag is element tElement of mTags then
			put tElement into mSelected
			exit repeat
		end if
	end repeat
Trevor DeVore
ScreenSteps - https://www.screensteps.com

LiveCode Repos - https://github.com/search?q=user%3Atrevordevore+topic:livecode
LiveCode Builder Repos - https://github.com/search?q=user%3Atrevordevore+topic:livecode-builder

livecodeali
Livecode Staff Member
Livecode Staff Member
Posts: 192
Joined: Thu Apr 18, 2013 2:48 pm

Re: Finding element in list and getting offset

Post by livecodeali » Wed Feb 18, 2015 3:57 pm

Hi Trevor,

Yes you are correct that it doesn't currently exist - we probably should add it for consistency with the other chunk offset functions. Your workaround is probably only marginally less efficient than using such a function though.

Ali

trevordevore
VIP Livecode Opensource Backer
VIP Livecode Opensource Backer
Posts: 1005
Joined: Sat Apr 08, 2006 3:06 pm
Location: Overland Park, Kansas
Contact:

Re: Finding element in list and getting offset

Post by trevordevore » Wed Feb 18, 2015 4:11 pm

I agree that it should be added for consistency. I don't know about others, but this is a common operation for me when using lists.
Trevor DeVore
ScreenSteps - https://www.screensteps.com

LiveCode Repos - https://github.com/search?q=user%3Atrevordevore+topic:livecode
LiveCode Builder Repos - https://github.com/search?q=user%3Atrevordevore+topic:livecode-builder

livecodeali
Livecode Staff Member
Livecode Staff Member
Posts: 192
Joined: Thu Apr 18, 2013 2:48 pm

Re: Finding element in list and getting offset

Post by livecodeali » Wed Feb 18, 2015 7:30 pm


Post Reply

Return to “LiveCode Builder”