is it seqable?

clerk traverses sequable? collections, see https://book.clerk.vision/#presentation

> Here, we're giving it a set with 1, 2, 3 in it. In its generalized form, present is a function that does a depth-first traversal of a given tree, starting at the root node. It will select a viewer for this root node, and unless told otherwise, descend further down the tree to present its child nodes.

But it does not render anything, see screenshot.

would need a proper repro to say anything

I made one here: https://github.com/behrica/clerkPythonIssue As it uses libpython-clj you need to get that set-up. The repo above contains a .devcontainer config, which can create a suitable setup on keypress in Docker. (using VSCode or devpod)

Open in "Codespaces" would work out-of-the box as well. (has free tier)

Quickly tried and couldn’t get a much “saner” print representation of the dataset over nREPL either. If the call py/->jvm is the way to go to have a decent one and you want it to be the default for pyobject values you could use a viewer like:

(def pyclj-viewer
  {:pred (comp #{:pyobject} type)
   :transform-fn (clerk/update-val py/->jvm)})

(clerk/add-viewers! [pyclj-viewer])

> What I find curious is, that rendering such object is not the same as rendering (str ..) a string is (should 🙂) always be printable in Clerk because we apply some pagination which prevent the above issues

I was coming from the "java world", so I made this probably wrong assumption, that Clerk should at a certain moment call "toString" when getting a "unknown Java type". This would be reasonable to do in Java, as a lot of Java classes implement "toString" reasonably well. In my concrete case, the "unknown object" is as well sequable?, which probably triggers a certain viewer. But then something goes wrong, as the items of the objects are "strings" (long strings). -> which should trigger the eliding of the string and cut it and prevent crash But this does not happen. So maybe there is something to improve on Clerk side ?

Ok, I guess seqable? is not enough, we assume an object to be sequential? to recursively present its components (don’t recall why atm). If you call

(viewer/viewer-for (clerk/get-default-viewers)
                     (py/py. datasets-module fetch_20newsgroups)) 

yes, this "object" is weird. In libpython-clj the python object wrappers implement certain clojure related java classes to behave "as much as possible" as Clojure types

>> you see the pyclj object actually dispatches to the fallback viewer, which essentially does a pr-str and sends the whole EDN data to the client.

any reason that no "string shortening" gets done in this case, as it gets done for "String" ?

These 2 as well behave well: