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Posted to user@flink.apache.org by otherwise777 <wo...@onzichtbaar.net> on 2016/11/17 12:31:29 UTC
Type of TypeVariable 'K' in 'class <> could not be determined
I get this error:
*Exception in thread "main"
org.apache.flink.api.common.functions.InvalidTypesException: Type of
TypeVariable 'K' in 'class
Tgraphs.SingleSourceShortestTemporalPathEAT3$InitVerticesMapper' could not
be determined. This is most likely a type erasure problem. The type
extraction currently supports types with generic variables only in cases
where all variables in the return type can be deduced from the input
type(s).*
When i run my function:
*tempgraphdoubles.run(new
SingleSourceShortestTemporalPathEAT3<String,NullValue>("A",maxIterations)).print();*
The function is here: http://paste.thezomg.com/19924/93864391/
<http://paste.thezomg.com/19924/93864391/>
I've narrowed it down to the Tuple2<K,Double> on line 44, apperently it
doesn't like the K being there in a Tuple2<>
I couldn't find out why though, and how would i make a workaround for this
when i a want to use this scenario?
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Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by otherwise777 <wo...@onzichtbaar.net>.
Sorry i already pushed a new update,
But in testclass.java if you change line 266 to:
tempgraphdoubles.run(new
SingleSourceShortestTemporalPathEAT3<String,NullValue>(maxIterations)).print();
And then run the testclass.java You should get the error
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Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Vasiliki Kalavri <va...@gmail.com>.
Thanks Timo for the explanation and Wouter for reporting this. I've located
two more instances of this in the Graph class and created FLINK5097. I'll
ping you after I open the PR if that's OK.
-Vasia.
On 18 November 2016 at 12:22, Timo Walther <tw...@apache.org> wrote:
> Yes. I don't know if it solve this problem but in general if the input
> type is known it should be passed for input type inference.
>
> Am 18/11/16 um 11:28 schrieb Vasiliki Kalavri:
>
> Hi Timo,
>
> thanks for looking into this! Are you referring to the 4th argument in [1]?
>
> Thanks,
> -Vasia.
>
> [1]: https://github.com/apache/flink/blob/master/flink-
> libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java#L506
>
> On 18 November 2016 at 10:25, Timo Walther <tw...@apache.org> wrote:
>
>> I think I identified the problem. Input type inference can not be used
>> because of missing information.
>>
>> @Vasia: Why is the TypeExtractor in Graph. mapVertices(mapper) called
>> without information about the input type? Isn't the input of the
>> MapFunction known at this point? ( vertices.getType())
>>
>> Am 17/11/16 um 20:24 schrieb otherwise777:
>>
>> The one that's currently in my github will give you the error,
>>>
>>> In my other file i made a really ugly workaround by adding the element
>>> in an
>>> ArrayList<K> as a single item.
>>>
>>>
>>>
>>> --
>>> View this message in context: http://apache-flink-user-maili
>>> ng-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K
>>> -in-class-could-not-be-determined-tp10173p10184.html
>>> Sent from the Apache Flink User Mailing List archive. mailing list
>>> archive at Nabble.com.
>>>
>>
>
>
> --
> Freundliche Grüße / Kind Regards
>
> Timo Walther
>
> Follow me: @twalthrhttps://www.linkedin.com/in/twalthr
>
>
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Timo Walther <tw...@apache.org>.
Yes. I don't know if it solve this problem but in general if the input
type is known it should be passed for input type inference.
Am 18/11/16 um 11:28 schrieb Vasiliki Kalavri:
> Hi Timo,
>
> thanks for looking into this! Are you referring to the 4th argument in
> [1]?
>
> Thanks,
> -Vasia.
>
> [1]:
> https://github.com/apache/flink/blob/master/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java#L506
> <https://github.com/apache/flink/blob/master/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/Graph.java#L506>
>
> On 18 November 2016 at 10:25, Timo Walther <twalthr@apache.org
> <ma...@apache.org>> wrote:
>
> I think I identified the problem. Input type inference can not be
> used because of missing information.
>
> @Vasia: Why is the TypeExtractor in Graph. mapVertices(mapper)
> called without information about the input type? Isn't the input
> of the MapFunction known at this point? ( vertices.getType())
>
> Am 17/11/16 um 20:24 schrieb otherwise777:
>
> The one that's currently in my github will give you the error,
>
> In my other file i made a really ugly workaround by adding the
> element in an
> ArrayList<K> as a single item.
>
>
>
> --
> View this message in context:
> http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173p10184.html
> <http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173p10184.html>
> Sent from the Apache Flink User Mailing List archive. mailing
> list archive at Nabble.com.
>
>
--
Freundliche Gr��e / Kind Regards
Timo Walther
Follow me: @twalthr
https://www.linkedin.com/in/twalthr
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Vasiliki Kalavri <va...@gmail.com>.
Hi Timo,
thanks for looking into this! Are you referring to the 4th argument in [1]?
Thanks,
-Vasia.
[1]: https://github.com/apache/flink/blob/master/
flink-libraries/flink-gelly/src/main/java/org/apache/
flink/graph/Graph.java#L506
On 18 November 2016 at 10:25, Timo Walther <tw...@apache.org> wrote:
> I think I identified the problem. Input type inference can not be used
> because of missing information.
>
> @Vasia: Why is the TypeExtractor in Graph. mapVertices(mapper) called
> without information about the input type? Isn't the input of the
> MapFunction known at this point? ( vertices.getType())
>
> Am 17/11/16 um 20:24 schrieb otherwise777:
>
> The one that's currently in my github will give you the error,
>>
>> In my other file i made a really ugly workaround by adding the element in
>> an
>> ArrayList<K> as a single item.
>>
>>
>>
>> --
>> View this message in context: http://apache-flink-user-maili
>> ng-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-
>> K-in-class-could-not-be-determined-tp10173p10184.html
>> Sent from the Apache Flink User Mailing List archive. mailing list
>> archive at Nabble.com.
>>
>
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Timo Walther <tw...@apache.org>.
I think I identified the problem. Input type inference can not be used
because of missing information.
@Vasia: Why is the TypeExtractor in Graph. mapVertices(mapper) called
without information about the input type? Isn't the input of the
MapFunction known at this point? ( vertices.getType())
Am 17/11/16 um 20:24 schrieb otherwise777:
> The one that's currently in my github will give you the error,
>
> In my other file i made a really ugly workaround by adding the element in an
> ArrayList<K> as a single item.
>
>
>
> --
> View this message in context: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173p10184.html
> Sent from the Apache Flink User Mailing List archive. mailing list archive at Nabble.com.
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by otherwise777 <wo...@onzichtbaar.net>.
The one that's currently in my github will give you the error,
In my other file i made a really ugly workaround by adding the element in an
ArrayList<K> as a single item.
--
View this message in context: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173p10184.html
Sent from the Apache Flink User Mailing List archive. mailing list archive at Nabble.com.
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Timo Walther <tw...@apache.org>.
I checked out your repository. Which test do I have to run in order to
get the error?
Am 17/11/16 um 14:33 schrieb otherwise777:
> Hey Vasia,
>
> I made this simple mapper to illustrate the problem, the file i'm working on
> is here:
> https://github.com/otherwise777/Temporal_Graph_library/blob/master/src/main/java/Tgraphs/SingleSourceShortestTemporalPathEATBetweenness.java
> <https://github.com/otherwise777/Temporal_Graph_library/blob/master/src/main/java/Tgraphs/SingleSourceShortestTemporalPathEATBetweenness.java>
>
> Which uses a Tuple3<K,Double,ArrayList<K>>
>
> Anyhow, you can ignore the scatter-gather UDFs from the file that i posted
>
>
>
> --
> View this message in context: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173p10177.html
> Sent from the Apache Flink User Mailing List archive. mailing list archive at Nabble.com.
--
Freundliche Gre / Kind Regards
Timo Walther
Follow me: @twalthr
https://www.linkedin.com/in/twalthr
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by otherwise777 <wo...@onzichtbaar.net>.
Hey Vasia,
I made this simple mapper to illustrate the problem, the file i'm working on
is here:
https://github.com/otherwise777/Temporal_Graph_library/blob/master/src/main/java/Tgraphs/SingleSourceShortestTemporalPathEATBetweenness.java
<https://github.com/otherwise777/Temporal_Graph_library/blob/master/src/main/java/Tgraphs/SingleSourceShortestTemporalPathEATBetweenness.java>
Which uses a Tuple3<K,Double,ArrayList<K>>
Anyhow, you can ignore the scatter-gather UDFs from the file that i posted
--
View this message in context: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173p10177.html
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Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Vasiliki Kalavri <va...@gmail.com>.
Hi Wouter,
with InitVerticesMapper() are you trying to map the vertex value to a
Tuple2<K, Double> or to a Double?
Your mapper is turning the vertex values into a Tuple2<> but your
scatter-gather UDFs are defining Double vertex values.
-Vasia.
On 17 November 2016 at 14:03, otherwise777 <wo...@onzichtbaar.net> wrote:
> Hello timo,
>
> the whole project is on github:
> https://github.com/otherwise777/Temporal_Graph_library
> <https://github.com/otherwise777/Temporal_Graph_library>
> The Tgraphalgorithm is here:
> https://github.com/otherwise777/Temporal_Graph_
> library/blob/master/src/main/java/Tgraphs/TGraphAlgorithm.java
> <https://github.com/otherwise777/Temporal_Graph_
> library/blob/master/src/main/java/Tgraphs/TGraphAlgorithm.java>
>
> I just updated Flink and Gelly to 1.1.3 with Maven but the problem still
> occurs
>
>
>
> --
> View this message in context: http://apache-flink-user-
> mailing-list-archive.2336050.n4.nabble.com/Type-of-
> TypeVariable-K-in-class-could-not-be-determined-tp10173p10175.html
> Sent from the Apache Flink User Mailing List archive. mailing list archive
> at Nabble.com.
>
Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by otherwise777 <wo...@onzichtbaar.net>.
Hello timo,
the whole project is on github:
https://github.com/otherwise777/Temporal_Graph_library
<https://github.com/otherwise777/Temporal_Graph_library>
The Tgraphalgorithm is here:
https://github.com/otherwise777/Temporal_Graph_library/blob/master/src/main/java/Tgraphs/TGraphAlgorithm.java
<https://github.com/otherwise777/Temporal_Graph_library/blob/master/src/main/java/Tgraphs/TGraphAlgorithm.java>
I just updated Flink and Gelly to 1.1.3 with Maven but the problem still
occurs
--
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Re: Type of TypeVariable 'K' in 'class <> could not be determined
Posted by Timo Walther <tw...@apache.org>.
Hi,
Flink uses the signature of the class to determine the return types of a
function ("class MyClass implements MapFunction<IN, OUT>"). You always
have to keep in mind that every generic in a "new
XXXX<String,NullValue>()" gets erasured by Java to "new XXXX()". So
variable K has to be determined by the input type (which is always known).
It would be great if you could also share " TGraphAlgorithm" and all
classes till Function in the hierarchy. According to your comment in "
SingleSourceShortestTemporalPathEAT3" K is in the input type, so this
could be a bug. Have you tried the latest snapshot release? There were
some type inference improvements lately.
Regards,
Timo
Am 17/11/16 um 13:31 schrieb otherwise777:
> I get this error:
>
> *Exception in thread "main"
> org.apache.flink.api.common.functions.InvalidTypesException: Type of
> TypeVariable 'K' in 'class
> Tgraphs.SingleSourceShortestTemporalPathEAT3$InitVerticesMapper' could not
> be determined. This is most likely a type erasure problem. The type
> extraction currently supports types with generic variables only in cases
> where all variables in the return type can be deduced from the input
> type(s).*
>
> When i run my function:
>
> *tempgraphdoubles.run(new
> SingleSourceShortestTemporalPathEAT3<String,NullValue>("A",maxIterations)).print();*
>
> The function is here: http://paste.thezomg.com/19924/93864391/
> <http://paste.thezomg.com/19924/93864391/>
>
> I've narrowed it down to the Tuple2<K,Double> on line 44, apperently it
> doesn't like the K being there in a Tuple2<>
>
> I couldn't find out why though, and how would i make a workaround for this
> when i a want to use this scenario?
>
>
>
> --
> View this message in context: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Type-of-TypeVariable-K-in-class-could-not-be-determined-tp10173.html
> Sent from the Apache Flink User Mailing List archive. mailing list archive at Nabble.com.