Clojurians Log v2

Should the second opts in line 17 be opts+specs? Otherwise that argument doesn't seem to be used?

Oh, right, I renamed the macro argument but forgot to update the binding

My personal feeling is that this is too much "magic" and it makes it very hard to just look at code and figure out what it actually does. I mean, how often do you really need a record to implement an arbitrary list of protocols -- and what are those implementations actually doing in this case?

OK, so macroexpand-1 seems to indicate this is just adding delegation of those protocols via the first field of the record -- but I don't understand why. What's the motivation for this (the discussion was some time ago)?

Also, if we're talking about Component, we're tending to implement Lifecycle via metadata a lot these days at work -- not records.

(although, unfortunately, IKVReduce doesn't support extension via metadata)

It's a balancing act between readability, convenience and "magic"

Let's say I want to bring in something like a malli registry or reitit router as a component

I can extend them via metadata, or I can just stick them as a "state" in a component and delegate their methods to them

Then the components appear very "vanilla"

They just have a list of "here are all the protocols (and interfaces?) I delegate to"

When I settle on how I want to do interfaces, too, I get a convenient way of delegating over java objects, too, which I can't extend via metadata

But take next.jdbc as another example, I can just specify a list of protocols on a record and it can "automagically" participate in them

no boilerplate, no wrapping, and no difference in semantics

What next.jdbc protocols would you want to delegate to? That's not a compelling argument to me. next.jdbc.connection/component already exists for making a Component that wraps a pooled datasource. What other things would you want to do?

This is just not a problem I've run into, so maybe it's specific to a couple of the libraries you're using that sort of expect you to implement a bunch of protocols with boilerplate?

I can give several examples • with next.jdbc I might not want to use the component wrapper, just due to preference • https://github.com/metosin/reitit/blob/master/modules/reitit-core/src/reitit/core.cljc#L38 • https://github.com/metosin/malli/blob/master/src/malli/registry.cljc#L8

The router example - depends on handlers. Handlers might be stateful (they might call a db)