Unused parameter in function ProjectionDescriptor.createPojoJavaImplementation()

[CarloMariaProietti]

The current function is as follows; inputType is unused.

private static <Input, Output> FunctionDescriptor.SerializableFunction<Input, Output> createPojoJavaImplementation(
            final String[] fieldNames, final BasicDataUnitType<Input> inputType) {
        // Get the names of the fields to be projected.
        if (fieldNames.length != 1) {
            return t -> {
                throw new IllegalStateException("The projection descriptor currently supports only a single field.");
            };
        }
        final String fieldName = fieldNames[0];
        return new PojoImplementation<>(fieldName);
    }

[AjayBoddeda4]

Hi Carlo, thank you for flagging this. I was looking at ProjectionDescriptor while studying the codebase for the DataFrame API proposal.
The inputType parameter appears to be passed in but never used in the method body — the implementation only uses fieldNames to create the PojoImplementation.
One possible fix would be to either remove the inputType parameter entirely if it is not needed, or use it to add type validation before the projection — for example checking that the input type actually has the requested field. This would make the DataFrame API's select() operation more robust when users specify column names.
Would love to contribute a fix for this if guidance is provided on the preferred approach!

[sawantbandita]

Hi, I would like to work on this issue. I propose to remove the unused inputTypeparameter from the method to improve code clarity, since it is currently not used in the implementation.