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From Timo Walther <twal...@apache.org>
Subject Re: [DISCUSSION] Type hints versus TypeInfoParser
Date Wed, 18 Nov 2015 17:03:15 GMT
If the TypeExtractor is not able to handle the fields of a Pojo 
correctly, the String parser is quite useful to say 
"org.my.Pojo<field1=Tuple2<String,Long>>". Doing this with 
TypeInformation classes is terrible. But I think this a corner case we 
can ignore. I would also remove the ".returns(String)" in favor of 
TypeHints, but let the TypeInfoParser remain in a typeutils package 
(internal tool).

Regards,
Timo

On 18.11.2015 16:47, Stephan Ewen wrote:
> If we want to drop any of the possible ".returns(...)" methods (like class
> or string) we should do that now.
>
> The "class" method is probably redundant anyways, as the hints are only
> necessary in generics are involved (where class does not help anyways).
>
> @Timo: What can the String do what the TypeHint cannot do?
>
> On Wed, Nov 11, 2015 at 9:06 PM, Timo Walther <twalthr@apache.org> wrote:
>
>> +1
>>
>> It's still hacky but we don't have better alternatives.
>>
>> I'm not 100% sure if we can get rid of the parser. I think it's still a
>> nice way for quickly defining the fields of a POJO if the type extractor
>> fails to analyze it. But actually I don't know an example where it fails.
>>
>> Regards,
>> Timo
>>
>>
>> On 11.11.2015 19:56, Aljoscha Krettek wrote:
>>
>>> Big +1
>>>
>>> Of course, we had the initial talk about it… :D
>>>
>>>> On 11 Nov 2015, at 19:33, Kirschnick, Johannes <
>>>> johannes.kirschnick@tu-berlin.de> wrote:
>>>>
>>>> Hi Stephan,
>>>>
>>>> looking at the TypeHint, I got reminded on how Gson (a Json Parser)
>>>> handles this situation of parsing generics.
>>>>
>>>> See here for an overview
>>>>
>>>> https://sites.google.com/site/gson/gson-user-guide#TOC-Serializing-and-Deserializing-Generic-Types
>>>>
>>>> Seems like this method was rediscovered :) And maybe there are some
>>>> tricks that can be learned from the implementation
>>>>
>>>> I'm all in favor for "hard" types over string literals.
>>>>
>>>> Johannes
>>>>
>>>> P.S.
>>>> Apparently GWT uses the same "trick" to handle generics ...
>>>>
>>>> -----Ursprüngliche Nachricht-----
>>>> Von: ewenstephan@gmail.com [mailto:ewenstephan@gmail.com] Im Auftrag
>>>> von Stephan Ewen
>>>> Gesendet: Mittwoch, 11. November 2015 15:53
>>>> An: dev@flink.apache.org
>>>> Betreff: [DISCUSSION] Type hints versus TypeInfoParser
>>>>
>>>> Hi all!
>>>>
>>>> We discovered a nice way to give TypeHints in the Google Cloud Dataflow
>>>> SDK, in a way that would fit Flink perfectly. I created a JIRA for that:
>>>> https://issues.apache.org/jira/browse/FLINK-2788
>>>>
>>>> Since this is more powerful and type safe than the String/Parser way of
>>>> giving hints, I was wondering whether we should add this and deprecate the
>>>> String variant. If we do that, 1.0 is the time to do that.
>>>>
>>>> What do you think about this idea?
>>>>
>>>> @Timo Walther Since you worked a lot on types/parser/etc - what is your
>>>> take on this?
>>>>
>>>> Greetings,
>>>> Stephan
>>>>


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