Clojure Q&A - Recent questions tagged datafy

Will REBL be open-sourced?

Sat, 11 Sep 2021 17:01:54 +0000

On the assumption that it doesn't play any tricks that are not available to other Datomic users, what are the reasons for keeping it as a private repo?

Are there plans for official docs (rationale and guide) on datafy / nav?

Sat, 11 Sep 2021 10:26:57 +0000

If Clojure is to become (even) more data oriented, these are powerful tools to achieve that goal. The community needs support to encourage adoption.

The current state of documentation for datafy and nav is not sufficient IMHO to encourage independent learning on a broad scale.

There is no canonical source of such documentation in the community despite some valiant efforts (eg @SeanCorfield who has a great blog post and is an active proponent).

Examples are difficult to find around the internet ... here's a good one from a Slack recommendation by @Frederick on there.

We know that there are problems with Slack since we cannot easily search history so keeping it here might help people find it in the meantime.

It would be good to have a rationale explaining the problem it is solving, the general approach and some specifics on the design.

Likewise a guide on how it should be used with a worked example and some hints and tips on how to approach implementations.

I know it's marked as alpha but this has not prevented docs on other aspects of the language.

Where does one place a nav function when implementing Navigable protocol?

Tue, 04 Feb 2020 22:26:49 +0000

I have a map structure that looks like this

 {:a "this"
  :b {:x "foo" :y 1}
  :c "that"
  :d {:x "bar" :y 2}
  :e "the other"}

That is, a top-level map that contains several keys, some of which have as values maps that conform to the same structure.

The values of :x and :y in that inner map structure can be applied to a function that would retrieve another map or datafyable object that I might navigate to. This led me to think of implementing the Navigable protocol so that I might use a REBL to browse through this data.

To do this I understand that I need to create a (nav coll k v) function and apply it as metadata to the map. My question is this:

Does the nav function belong on the top-level map or on each of the inner maps?

Can someone explain the arguments to nav ?

Fri, 06 Sep 2019 00:54:40 +0000

The clojure.protocols/nav function has signature:

[coll k v]

I don't understand what coll, k and v would be. Can someone explain? Maybe give an example of calling nav with realistic arguments?

For instance, what is coll. Is it supposed to be the result of a prior call to datafy? Thus is coll what we will navigate into, or is that v?

I assume k is the required information to drill down.

Now there is v, so again, I'm not sure if this is meant to be the value we are navigating into? But if so, what is coll ? If v isn't that, than I don't understand what it should be. Isn't the value what we want nav to return, why do we provide it as well?

Thank You