[
https://issues.apache.org/jira/browse/FLINK-1906?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14501513#comment-14501513
]
ASF GitHub Bot commented on FLINK-1906:
---------------------------------------
GitHub user chiwanpark opened a pull request:
https://github.com/apache/flink/pull/611
[FLINK-1906] [docs] Add tip to work around plain Tuple return type of
project operator
Add a tip about project transformation with type hinting in documentation.
Related JIRA is [here](https://issues.apache.org/jira/browse/FLINK-1906).
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/chiwanpark/flink FLINK-1906
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/611.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #611
----
commit fd784be28c8f6bd85019e653a131975c36e7f2d0
Author: Chiwan Park <chiwanp...@icloud.com>
Date: 2015-04-18T18:24:16Z
[FLINK-1906] [docs] Add tip to work around plain Tuple return type of
project operator
----
> Add tip to work around plain Tuple return type of project operator
> ------------------------------------------------------------------
>
> Key: FLINK-1906
> URL: https://issues.apache.org/jira/browse/FLINK-1906
> Project: Flink
> Issue Type: Improvement
> Components: Documentation
> Affects Versions: 0.9
> Reporter: Fabian Hueske
> Assignee: Chiwan Park
> Priority: Minor
> Labels: starter
>
> The Java compiler is not able to infer the return type of the {{project}}
> operator and defaults to {{Tuple}}. This can cause problems if another
> operator is immediately called on the result of a {{project}} operator such
> as:
> {code}
> DataSet<Tuple5<String,String,String,String,String>> ds = ....
> DataSet<Tuple1<String>> ds2 = ds.project(0).distinct(0);
> {code}
> This problem can be overcome by hinting the return type of {{project}} like
> this:
> {code}
> DataSet<Tuple1<String>> ds2 = ds.<Tuple1<String>project(0).distinct(0);
> {code}
> We should add this description to the documentation of the project operator.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
