I would like to loop this back a layer. Current, there is a discussion in the
MXNet Scala community on the ways to implement the Java APIs. Currently there
are two thoughts:
1. Make Scala Java Friendly (Create Java compatible methods in the Scala Class.
such as NDArray with Java compatible constructor)
2. Make Java friendly wrappers in Scala (Andrew's explanation below)
The first approach require minimum input from our side to implement however
bring user a bunch of useless api they may not want to use. It also makes Scala
package heavier. The good thing is these two packages require minimum
maintenance cost. As a tradeoff, if any time in the future we want to make Java
big (make Java as the primary language supported by MXNet), then the migration
from Scala to Java will be harmful. Spark consider this carefully and decide
not to change much on their Scala code base to make it more Java.
The second approach will make unique NDArray, Shape, Context and more. The good
thing about this is we can always holds a version control on Java. Some
breaking changes on Scala may not influence much on Java. It did the best way
to decouple the module and good for us to build unique pipeline for Java. The
bad thing with this design is the maintenance cost as we need to keep two code
bases, but it also make Java side easy to change to make it better compatible
with users.
Thanks,
Qing
On 9/27/18, 3:25 PM, "Andrew Ayres" <andrew.f.ay...@gmail.com> wrote:
Hi,
Currently, we're working to implement a new Java API and would like some
feedback from the community on an implementation detail. In short, the new
Java API will use the existing Scala API (in a manner similar to how the
current Clojure API works). This basically means that we're making Java
friendly wrappers to call the existing Scala API.
The feedback we're looking for is on the implementation of NDArray. Scala's
NDArray has a significant amount of code which is generated via macros and
we've got two viable paths to move forward:
1.) Change the macro to generate Java friendly methods - To do this we'll
modify the macro so that the generated methods won't have default/optional
arguments. There may also have to be some changes to parameter types to
make them Java friendly. The big advantage here is that ongoing maintenance
will easier. The disadvantages are that we'll be changing the existing
Scala NDArray Infer API (it's marked experimental) and Scala users will
lose the ability to use the default and optional arguments.
2.) Leave the existing macro in place and add another which generates a
Java friendly version - The biggest issue here is that we'll be doubling
the number of macros that we've got to maintain. It'll become even more
overhead once we start expanding the Java API with more classes that use
generated code like this. The advantages are that the existing Scala
NDArray Infer API would remain unchanged for Scala users and that the new
macro could be optimized to give the best possible experience to the Java
API.
Thanks,
Andrew
