Refine functions and add parsing test to set and zset

[zncleon]

• Refine functions
  spop
srandmember
zpop

• Add parsing test
  spop
srandmember
zadd
zincby
zlexcount
zpop
zunionstore

In addition, srandmember not consider the case of a negative count and return an empty list or set，should we give it a definite action?

Close #1469

[git-hulk]

LGTM

Thanks for your contribution.

[git-hulk]

Hi @zncleon

In addition, srandmember not consider the case of a negative count and return an empty list or set，should we give it a definite action?

In this case, we can behave consistently with the Redis.

[infdahai]

a nice contribution!

[zncleon]

ok，@git-hulk

In this case, we can behave consistently with the Redis.

now srandmember only returns always first N members if not changed.
I will implement its(as well as zrandmember #1459) random algorithm according to Redis.

[infdahai]

yeah, you can do this(or give a new PR about this special problem).

[git-hulk]

ok，@git-hulk

In this case, we can behave consistently with the Redis.

now srandmember only returns always first N members if not changed. I will implement its(as well as zrandmember #1459) random algorithm according to Redis.

@zncleon Cool, can submit an issue to track this.

[git-hulk]

Thanks all, mergin...