Simple way to check if something is -not- in contents?

ID:161815
 
Mar 29 2008, 2:13 am
Ok I'm pretty sure I'm not using the best way to do this and I'm getting a little tired of typing this in my code all the time.

But lets say you have a proc that teaches someone a skill, but only if they dont already have it, as demonstrated (badly) in the below code:
obj/Skill/Jump
mob/proc/Learn()
 for(var/obj/Skill/Jump/A in contents) return
 contents+=new/obj/Skill/Jump
 src<<"You learned Jump"

I tried this too but it didnt work
for(!var/obj/Skill/Jump/A in contents) contents+=new/obj/Skill/Jump

But I really didn't expect it to work.

Can anyone tell me a better way to see if something is NOT in your contents and if not add that thing to your contents?

And what about:
if(!contents.Find(/obj/Skill/Jump)) contents+=new/obj/Skill/Jump
?
Mar 29 2008, 2:24 am
1) Learn about the operational standing (that is, what operators have more priority)...

See [link] for an example of how not knowing them can do >_>

2) Maybe you want to locate(/path) in Ref.contents? 
if(!(locate(X) in Y.contents)) Z.Move(Y)
if(!(locate(X) in Y)) Y.contents += Z

locate() returns only a single object reference, but in this case, that's alright since we only want one type.
Mar 29 2008, 2:40 am
In response to GhostAnime
So that brings me to another question.

Saying "in something" does the same thing (functionally) as "in something.contents"?
Mar 29 2008, 2:44 am
In response to Dragonn
When you check 'in' an object, you are checking its contents (useful shortcut, neh?).

Of course that is if it is a datum or a variant of /atom (including /mob and the other hierarchy branches). For /list, it checks through the entries: 
if(!(X in list(A,B,C))) CRASH("How come 'X' is not 'A', 'B' or 'C'?!")
Mar 29 2008, 2:52 am
Why would that not work? it looks like it will work just fine
Mar 29 2008, 2:56 am
In response to Lt. Pain
He is basically looking for (0 or 1) in X.contents, due to the higher operational standing ! has (note the ID that I placed in the my post here earlier to see how one person had problems with it).

Though I am not sure how exactly it would affect it in for() (other than you are looking for a numerical value) and right before a variable...