Stal
Set algebra solver for Redis
Description
Stal
receives an array with an s-expression composed of commands
and key names and resolves the set operations in Redis.
Community
Meet us on IRC: #lesscode on freenode.net.
Getting started
Install Redis. On most platforms it's as easy as grabbing
the sources, running make and then putting the redis-server
binary
in the PATH.
Once you have it installed, you can execute redis-server
and it
will run on localhost:6379
by default. Check the redis.conf
file that comes with the sources if you want to change some settings.
Usage
Stal
requires a Resp compatible client. To make things
easier, resp
is listed as a runtime dependency so the examples
in this document will work.
require "stal"
# Connect the client to the default host
resp = Resp.new("redis://localhost:6379")
# Use the Redis client to populate some sets
resp.call("SADD", "foo", "a", "b", "c")
resp.call("SADD", "bar", "b", "c", "d")
resp.call("SADD", "baz", "c", "d", "e")
resp.call("SADD", "qux", "x", "y", "z")
Now we can perform some set operations with Stal
:
expr = ["SUNION", "qux", ["SDIFF", ["SINTER", "foo", "bar"], "baz"]]
Stal.solve(resp, expr)
#=> ["b", "x", "y", "z"]
Stal
translates the internal calls to "SUNION"
, "SDIFF"
and
"SINTER"
into SDIFFSTORE
, SINTERSTORE
and SUNIONSTORE
to
perform the underlying operations, and it takes care of generating
and deleting any temporary keys.
For more information, refer to the repository of the Stal script.
Installation
Add this to your application's shard.yml
:
dependencies:
stal:
github: soveran/stal-crystal
branch: master