Robert Burke created BEAM-7444:
----------------------------------
Summary: Support ReIterators in the code generator.
Key: BEAM-7444
URL: https://issues.apache.org/jira/browse/BEAM-7444
Project: Beam
Issue Type: Bug
Components: sdk-go
Reporter: Robert Burke
Currently trying to generate re-iterators for the Go SDK will generate
incorrect Go code (it won't compile).
Specifically, an iterator are parameters of the shape: func(*T) bool
while a re-iterator is of the shape func() func(*T) bool
That is, a re-iterator is a function that returns iterators.
The code generator's NameType method [1] should be updated to recognize the
signature of a re-iterator, have an added makeReIterator method that verifies
that it's a ReIterator, similar to makeInput for iterators [2]. Likely
makeReIterator will need to use makeInput to properly handle the check, similar
to how UnforldReIter is implemented.
[https://github.com/apache/beam/blob/a2b0ad14f1525d1a645cb26f5b8ec45692d9d54e/sdks/go/pkg/beam/core/funcx/sideinput.go#L92]
The returned iterator would need it's code generated for performance, by
recursively registring the return type.
[[1]https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/util/starcgenx/starcgenx.go#L596|https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/util/starcgenx/starcgenx.go#L596]
[2][https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/util/starcgenx/starcgenx.go#L532]
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
