Roku Developer Program

Join our online forum to talk to Roku developers and fellow channel creators. Ask questions, share tips with the community, and find helpful resources.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
EnTerr
Roku Guru

roAssociativeArray.append() with duplicate keys [solved]

Documentation is laconic
Append(aa as Object)
Append an AssociativeArray to this one.

It is unclear what happens if the same keys are present in both dictionaries? E.g. a={k:"a"} and b={k:"b"}, after a.append(b), should that be:
a) error during update
b) a.k = "a" (a prevails)
c) a.k = "b" (b prevails)
d) behavior undefined (can change in the future)

I tested and current behavior seems to be (c), as if a loop over b has been ran, doing a.AddReplace(). Roku*, can you state if this will be the behavior to rely on and document it?

PS. method probably should have been named "update()" since this implies new values win, compare to python's

PPS. there is a bug in ".append()" in that if one passes non-roAssociativeArray argument, nothing happens (not even an error). That does not sound meaningful by design. Currently by the doc it is "Append(aa as Object)" but i can feed it number, string, bool, function... with no apparent effect. So seems to be more of "dynamic" type
0 Kudos
16 REPLIES 16
EnTerr
Roku Guru

Re: roAssociativeArray.append() with duplicate keys

Bump.

Somebody from RokuCo, can you confirm this is guaranteed behavior?
It seems logical but can i rely on it.
0 Kudos
RokuJoel
Binge Watcher

Re: roAssociativeArray.append() with duplicate keys

Hi Enterr, I filed a bug on the last part of your posting (the lack of type checking) the day after you initially posted it.

Documentation - I can point that out to the documentation people.

- Joel
0 Kudos
EnTerr
Roku Guru

Re: roAssociativeArray.append() with duplicate keys

"RokuJoel" wrote:
Hi Enterr, I filed a bug on the last part of your posting (the lack of type checking) the day after you initially posted it.
Documentation - I can point that out to the documentation people.


Thanks Joel -
bump was regarding answer to my question. I guess the implication of what you are saying is that the new values are supposed to override old values for overlapping keys?

By the way, here is another one for reporting: roArray.append() acts the same way as append for roAA. For example, pop-quiz: what does this do:
a = [1,2,3]
a.append(4)
print a
a) print 1 2 3 4
b) error message

People coming from other languages (like python) will guess (a). The ones who have read the documentation and programmed only a little (like me) will expect (b). But the reality right now is
(c) none of the above, it will print 1 2 3
0 Kudos
EnTerr
Roku Guru

Re: roAssociativeArray.append() with duplicate keys

So what does it take to get an answer?
Am i asking too difficult of a question? Or is it my poor command of English.
0 Kudos
RokuJoel
Binge Watcher

Re: roAssociativeArray.append() with duplicate keys

Hi, as you noted "b" prevails. That would be the standard behavior that I don't think we would want to change. Of course, its software, so everything can change if someone decides to make it so as a matter of policy, or accidentally breaks something...

- Joel
0 Kudos
EnTerr
Roku Guru

Re: roAssociativeArray.append() with duplicate keys

"RokuJoel" wrote:
Hi, as you noted "b" prevails. That would be the standard behavior that I don't think we would want to change. Of course, its software, so everything can change if someone decides to make it so as a matter of policy, or accidentally breaks something...

Hi - appreciate an answer but since you don't seem certain, please run this by "a higher power" and get definitive answer that it will not in fact change.

It is customary to fix such details in the API and document that too. As i pointed out this is the guaranteed behavior in other languages (although there they use more fortunate name like ".update()" which just by name implies the behavior).

I will give you a reason so my question does not seem capricious: i intend to use this for (home-grown, class-less) object inheritance, so that new methods override parent's existing methods.
0 Kudos
TheEndless
Channel Surfer

Re: roAssociativeArray.append() with duplicate keys

"EnTerr" wrote:
I will give you a reason so my question does not seem capricious: i intend to use this for (home-grown, class-less) object inheritance, so that new methods override parent's existing methods.

I'm already using it like this as a fundamental feature of my framework, so I'm counting on it not changing! Looping through the keys individually is significantly slower (which, incidentally, can have a huge impact on the framerate of 2D API implementations).
My Channels: http://roku.permanence.com - Twitter: @TheEndlessDev
Instant Watch Browser (NetflixIWB), Aquarium Screensaver (AQUARIUM), Clever Clocks Screensaver (CLEVERCLOCKS), iTunes Podcasts (ITPC), My Channels (MYCHANNELS)
0 Kudos
RokuJoel
Binge Watcher

Re: roAssociativeArray.append() with duplicate keys

There will never be a definitive answer that something will not change. Anything that is likely to break channels, the way changing this would break channels, is unlikely to change, but that doesn't mean it won't change if there is a pressing reason to do so.

- Joel
0 Kudos
EnTerr
Roku Guru

[Solved!] roAssociativeArray.append() with duplicate keys

I notice that documentation has been updated to say
"ifAssociativeArray.Append(aa as Object)" wrote:
... If any key in aa are already associated with a value in this AssociativeArray, the current value is discarded and is replaced with the value in aa.
So it is behavior (B), the new AA overrides old AA content in case of overlapping keys. As any experienced developer would expect but now is in the RTFM and can be relied upon.

My gratitude goes to the forum's patron saint, RokuMarkn - thank you!
0 Kudos
Need Assistance?
Welcome to the Roku Community! Feel free to search our Community for answers or post your question to get help.

Become a Roku Streaming Expert!

Share your expertise, help fellow streamers, and unlock exclusive rewards as part of the Roku Community. Learn more.