[Feature request/question] Support for GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS client configuration option

[nwaywood]

I have been hunting through the source code and from what I can tell the only client config args that are supported currently are these six.

For a GRPC application that I am building atm (I only have control of the client side, not the server side) I need to set the GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS arg to true.

Is there an "unsafe" way for me to set this arg to true in my ClientConfig? Or does it need to be added as a sum type in the source code here?

Thanks in advance!

[Gabriella439]

@nwaywood: It requires a code change, even if you were to use the underlying unsafe primitives. The reason why is that the set of supported arguments is enumerated here:

gRPC-haskell/core/include/grpc_haskell.h

Lines 154 to 159 in 35163c3

	compression_algorithm_key = 0,
	compression_level_key,
	user_agent_prefix_key,
	user_agent_suffix_key,
	max_receive_message_length_key,
	max_metadata_size_key,

[nwaywood]

Ok, I'm happy to do a PR but I will need a bit more guidance about what I would need to change please. I am not very familiar with Haskell files that integrate with C (and my Haskell knowledge is beginner-intermediate)