Equality comparisons for ELEMENTS and :CREW are broken

[BobKermanIndustries]

Elements is broken right now, for example, ship:elements = ship:elements returns False, same with ship:elements[0]:parts = ship:elements[0]:parts or core:element = core:element, and searches in lists of elements is impossible with ship:elements:find(ship:elements[0]) returning -1 and for elem in ship:elements{print ship:elements:indexof(elem).} returning -1. I do not know what is causing this. The same problem appears to be with the :crew suffix, ship:crew = ship:crew or ship:crew[0] = ship:crew[0] returning False, but ship:crew:name seems to be fine.

[nuggreat]

Nope that is things working as they should. Most data structures in kOS are not stored in vars by value and instead stored by reference and for most cases when you preform an equality check on references if they are not the same reference then you get false from the equality check. This is mostly because writing by value equality checks for all kOS structures is both an insane amount of work and because the vast majority of such checks will match exactly what you get from just checking reference equality. This is why comparing the :NAME of kerbals works as that is comparing strings which is something that while passed by reference does by value equality.

What you need to do is write your own by value equality check which compares something that you can get by value unique to the structure. For elements you would likely need to iterate the part list of both elements and check that the UID for all parts in one list is found on one part of the other list.

EDIT:
something like this function for example should work through as difference instances of a given element list should be in the same order but I haven't checked that is actually the case.

FUNCTION are_elements_equal {
	PARAMETER elementA, elementB.
	LOCAL partsElementA TO elementA:PARTS.
	LOCAL partsElementB TO elementB:PARTS.
	LOCAL areEqual TO TRUE.
	IF partsElementA:LENGTH = partsElementB:LENGTH {
		FROM { LOCAL i IS partsElementA:LENGTH - 1. } UNTIL i < 0 STEP { SET i TO i - 1. } DO {
			IF partsElementA[i]:UID <> partsElementB[i]:UID {
				SET areEqual TO FALSE.
				BREAK.
			}
		}
	} ELSE {
		areEqual = FALSE.
	}
	RETURN areEqual.
}

[JonnyOThan]

Does this still happen since b9aad87 ?

[sug44]

This still happens. As nuggreat said this is how things are expected to work. On every access to these suffixes a new list is created. No simple way I see to fix this short of renaming all these suffixes to something like ship:buildelements(). I don't think this issue is a big deal