To summarize, Aurora is correct everywhere while Canary isn't ... and there's nothing is specs about removing the key if the value is undefined.
I take Aurora as the right one then, thanks a lot! On Thu, Jun 14, 2012 at 12:56 PM, Mark S. Miller <erig...@google.com> wrote: > On Thu, Jun 14, 2012 at 6:00 PM, Andrea Giammarchi > <andrea.giammar...@gmail.com> wrote: > > Hi again, > > here few inconsistencies I have found with latest version, for Mac, of > > these two dev/channel browsers. > > > > Map#set(key, value) > > Aurora: Map#set() returns undefined in any case. After, if value is > > undefined/void 0, Map#has(key) will return true and Map#get(key) will > return > > undefined/void 0 > > Canary: Map#set() returns the set value in any case. After, if value is > > undefined/void 0, Map#has(key) will return false. The key will be removed > > indeed so the get(key) will return undefined. > > > > My Take: > > returning the value with Map#set may become handier than returning > always > > undefined, in a JavaScript like code style. > > deleting implicitly the key makes no sense at all. Map has so much > focus > > on edge cases such NaN and +0 VS -0 but an explicit value as undefined is > > cannot be assigned as desired value BUT it can be used as key ?!?? > Implicit > > key removal goes against Map#delete(key) logic too since this method > returns > > true or false accordingly if the key was there or not. > > > > As Summary > > > > *anything value Map#set(anything key, anything value) looks the most > > concrete/meaningful signature without implicit Map#delete(key) calls ... > > please clarify if what I am saying makes sense and if both Aurora and > Canary > > will follow this behavior, thanks. > > I'd like to remind everyone that there's a draft spec at > <http://wiki.ecmascript.org/doku.php?id=harmony:simple_maps_and_sets>. > This is likely to change on the way to becoming official. But by this > spec, the behavior you report for Aurora is correct and Canary is > buggy. I'd appreciate it if you would file a bug report. Thanks. > > > > > > > > Set#delete(keyAsValue) > > Aurora: consistent behavior with Map#delete(key) ... the returned > value is > > a boolean, true or false if the key was there > > Canary: inconsistent behavior with Map#delete(key) ... > > Set#delete(keyAsValue) returns undefined and I really do not understand > why > > this is happening. My tests fails with surprise here while these where > green > > before ... bad choice, imho, I'd like to understand why is that. > > By the draft spec, again Aurora is correct and Canary is buggy. > > > > > Set#add(keyAsValue) > > both Aurora and Canary returns undefined here and I find this a bit > > inconsistent too. I see Set#add as a simplified Map#set where keyAsValue > > could be returned. > > Returning undefined is consistent both with Aurora's behavior for > Map#set and with the draft spec for Map#set. > > > > If your argument is that Set#add(keyAsValue) has different purpose than > > Map#set I wonder why the behavior is not consistent with Map#delete(key) > > where at least, Set#add(keyAsValue) could return true or false > accordingly > > if the keyAsValue was there or not. > > This may be a better design -- I can make arguments both ways and we > should have that argument. But that's the way it's currently (draft) > speced, so for the sake of browser agreement, we should follow the > draft spec until we agree on something else. > > OTOH, in alphas, betas, canarys, nightlys, or whatever prior to > official release, it's also good to experiment with changes one is > thinking of proposing -- in order to gain experience first. I doubt > that is what is happening here, but if it is, we should not discourage > it. > > > > > > if (Set#add(generic)) { > > // first time generic has been set > > } else { > > // generic was there already > > } > > > > My Take: > > while the returning boolean could be considered superfluous, since it > > could be implemented in Set#delete(generic) or simply passing through the > > Set#has(generic) check, returning the added generic value would be more > than > > helpful for many common tasks. > > > > mySingleSet.add(myGenericObject).methodCallOnAdd(/*args*/); > > > > Thanks for any sort of clarification. > > > > Best Regards, > > Andrea Giammarchi > > > > _______________________________________________ > > es-discuss mailing list > > es-discuss@mozilla.org > > https://mail.mozilla.org/listinfo/es-discuss > > > > > > -- > Cheers, > --MarkM >
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