I created https://issues.apache.org/jira/browse/FLINK-9798
> On 18. May 2018, at 16:10, Till Rohrmann <trohrm...@apache.org> wrote: > > +1 > > If we don't have a hierarchy of serializers then this method has no right > to exist. > > Cheers, > Till > > On Wed, May 16, 2018 at 11:06 AM, Timo Walther <twal...@apache.org> wrote: > >> +1 >> >> TypeInformation has too many methods that need to be implemented but >> provide little benefit for Flink. >> >> Am 16.05.18 um 10:55 schrieb Ted Yu: >> >> +1 from me as well. >>> >>> I checked a few serializer classes. The `equals` method on serializers >>> contains the logic of `canEqual` method whose existence seems redundant. >>> >>> On Wed, May 16, 2018 at 1:49 AM, Tzu-Li (Gordon) Tai <tzuli...@apache.org >>>> >>> wrote: >>> >>> +1. >>>> >>>> Looking at the implementations of the `canEqual` method in several >>>> serializers, it seems like all that is done is a check whether the object >>>> is of the same serializer class. >>>> We’ll have to be careful and double check all `equals` method on >>>> serializers that may have relied on the `canEqual` method to perform the >>>> preliminary type check. >>>> Otherwise, this sounds good. >>>> >>>> On 16 May 2018 at 4:35:47 PM, Stephan Ewen (se...@apache.org) wrote: >>>> >>>> Hi all! >>>> >>>> As part of an attempt to simplify some code in the TypeInfo and >>>> TypeSerializer area, I would like to drop the "canEqual" methods for the >>>> following reason: >>>> >>>> "canEqual()" is necessary to make proper equality checks across >>>> hierarchies >>>> of types. This is for example useful in a collection API, stating for >>>> example whether a List can be equal to a Collection if they have the same >>>> contents. We don't have that here. >>>> >>>> A certain type information (and serializer) is equal to another one if >>>> they >>>> describe the same type, strictly. There is no necessity for cross >>>> hierarchy >>>> checks. >>>> >>>> This has also let to the situation that most type infos and serializers >>>> implement just a dummy/default version of "canEqual". Many "equals()" >>>> methods do not even call the other object's "canEqual", etc. >>>> >>>> As a first step, we could simply deprecate the method and implement an >>>> empty default, and remove all calls to that method. >>>> >>>> Best, >>>> Stephan >>>> >>>> >>
