There are some things we need for computed values to be useful:
Cache on subscription keys, not the parent op #105
Invalidate on a user-defined function, not every time a sub changes (although that's a good default) & take in that user-defined function somewhere #108
Allow for computed values to depend on other computed values #107
Consider passing in the dependency as the first arg to the resolve callback instead of making the user make sure the string they entered in the cashay.computed is the same string they pass in for the options.dependency in subscribe.
There are some things we need for computed values to be useful:
cashay.computedis the same string they pass in for theoptions.dependencyinsubscribe.