Type information is lost when using the Pipeline function

[dqdinh]

Hi,

I’m using the pipeline function to do batch atomic Redis operations — https://github.com/debasishg/scala-redis/blob/master/src/main/scala/com/redis/RedisClient.scala#L113-L129

The pipeline function does not retain type information and instead lumps all transaction results as List[Any]. This is unfortunate because running any method off of RedisClient will return the correct type information.

Let me know if this a known issue or if I need to re-read the source and tests?

This is strange also because the tests show that the return types retains their type information (https://github.com/debasishg/scala-redis/blob/master/src/test/scala/com/redis/PipelineSpec.scala#L28-L36)

Other than converting the Any result to a string, parsing, and converting back to the target data structure, do you have any ideas on how to retain the type information for transactions using pipeline?

Here's my console output:

import com.redis._

val r = new RedisClient("localhost", 6379)

r.pipeline { p =>
         p.set("key", "debasish")
         p.get("key")
         p.get("key1")
       }.get

// res: List[Any] = List(true, Some(debasish), None)

 r.get("key")
// res: Option[String] = Some(debasish)

[debasishg]

Unless you are returning something like HList of Shapeless, List(true, Some(debasish), None) can only be typed as List[Any].
Also if you look at the function definition of pipeline, it returns an Option[List[Any]]. So, yeah, it's a known limitation and custom processing needs to be done at the client side to retrieve the types. Maybe using HList in redisclient can be an interesting idea to handle such situations.

[dqdinh]

Thanks for the feedback!