On Wed, Sep 13, 2017 at 1:17 PM, Eugene Kirpichov
<[EMAIL PROTECTED]lid> wrote:
Perhaps not, but does that mean it would be a Java-ism only or would
we implement it in Python despite it being worse there?
In Python it would be trivial to "slice" the side input arguments
across the lambdas in a natural way, but I can see that this would be
more of a pain in Java, especially as lambdas are unnecessarily
crippled during compilation.
Yeah, this is unfortunate. But, as mentioned, side inputs don't need
to be annotated, just counted. For something like inspecting the
window the NewDoFn has a lot of advantages over implicit access (and
makes it so you can't "forget" to declare your dependency), but I do
see advantages for the implicit way of doing things for delegating to
On the other hand, there is a bit of precedence for this: metrics have
the "implicit" api. If we do go this direction for side inputs, we
should also consider it for state and side outputs.