Clojurians Log v2

Methodical 0.12.0 is out -- notable features include https://github.com/camsaul/methodical/releases/tag/0.12.0 (click link for screenshot) and a handful of bugfixes. This was inspired by http://christophe.rhodes.io/notes/blog/posts/2018/sbcl_method_tracing/. Probably the most common reason I've heard against using fancy CLOS-style multimethods with :before , :after, and :around aux methods (like Methodical provides) is that they're harder to debug. That certainly used to be true. With the new trace facilities, Methodical multimethods are actually easier to debug than vanilla Clojure multimethods (allegedly). 😎

Very cool!

Also: lein-check-namespace-declshttps://github.com/camsaul/lein-check-namespace-decls#add-an-alias-to-depsedn`deps.edn`https://github.com/camsaul/lein-check-namespace-decls#add-an-alias-to-depsedn. Elevator pitch: Tired of people writing ns forms like

(ns my-namespace
  (:require [some.thing [else :as else] [x :as x]]            
            [another.namespace.b :as b]
            [didnt.even.use.this :as unused]
            [another.namespace.b :as b]
            [another.namespace.a :as a]))

I’m curious about what this does that clj-kondo doesn’t do for ns forms?

(it checks for duplicates, unused, and unsorted — I suspect the prefix/non-prefix syntax check is unique to l-c-n-d)

actually now that I look a little more closely, clj-kondo does 90% of what this linter does. 💀 I think enforcing prefix or non-prefix syntax might be the only difference. I wrote this a while before clj-kondo had namespace checking stuff tho. I mostly updated this just because I've been using deps.edn for new libraries lately and I wanted to port some existing tooling over. FWIW we're using both this linter and clj-kondo at Metabase. I'm more of a "can't have too many linters" person

I almost never see prefix requires (and I think they’re horrible) so they’d never get into our codebase because they wouldn’t pass PR review 🙂

@camsaul The README says “Add a :check-namespace-decls key to your project.clj to configure the way refactor-nrepl cleans namespaces. All options are passed directly to refactor-nrepl.” — how do you control this via CLI / deps.edn invocation?

(looking at the source, I could just pass all those options as :exec-args right? might want to mention that in the readme)

I like to have things like that that can be determined programmatically enforced by linters if possible.

Sorry, I guess I need to go thru the README again and make sure it makes sense now that it works with either Leiningen or deps.edn. You just pass all the options as :exec-args instead of under the :check-namespace-decls key in project.clj e.g.

{:aliases
 {:namespace-checker
  {:extra-deps {lein-check-namespace-decls/lein-check-namespace-decls {:mvn/version "1.0.4"}}
   :exec-fn    check-namespace-decls.core/check-namespace-decls
   :exec-args  {:prefix-rewriting false
                :source-paths     ["src" "test"]}}}}

Also on a side note RE prefix namespaces. We were using them at Metabase for a long time. I came around to the benefits of flat namespace declarations a while back but I didn't want to deal with converting a thousand namespaces over all at once so we kept using prefix ones for a long time. I finally did a big PR to convert everything in January: https://github.com/metabase/metabase/pull/14281 I ended up writing some Emacs Lisp to find and then iterate over every Clojure file in the entire project, load the namespace, and call cljr-clean-ns on them so I was able to do it all programmatically. Still a big change tho. So the linter helps ensure I don't end up having to do that sort of PR again 😅

@seancorfield while we're on the subject of linters do you know if anything else does something like this? https://github.com/camsaul/lein-docstring-checker This is next on my list to port. This one is about 4 years old at this point. I don't think a lot of people care enough about docstrings to enforce them with a linter but I've found that having an "either document it or make it private" rule works well for libraries. For big projects it makes refactors easier too since stuff ends up being private more often you don't have to spend time grepping the codebase before renaming stuff (or for Metabase, we support 3rd-party database drivers, so we have to be careful about breaking stuff 3rd-party drivers might be using, so keeping more stuff private lets us move faster and make more improvements to the core project) I don't want to waste time porting it and find out that clj-kondo/Eastwood/Bikeshed/Kibit/whatever added it last year 💀

That’s built into clj-kondo — I rely on that one a lot!

haha no way. I guess I need to pay more attention to what's going on with clj-kondo. 😅

I still use Eastwood as part of CI for one project but I mostly just rely on clj-kondo for everyday use now, esp since it’s integrated with editors and LSP etc and so it can run all the time while you are typing.

I think there are a lot of very specialized Leiningen plugins that really ought to just be archived at this point — they date back to a “simpler” era 🙂

Yeah. I might have to archive some of my old liters now. Better to pool efforts on Kondo and submit PRs there than to spend time maintaining old stuff

See also https://github.com/gfredericks/how-to-ns

and last but not least zprint supports formatting according to "How to ns" https://github.com/kkinnear/zprint/blob/master/doc/reference.md#how-to-ns

Maybe you can find a name if you ask the question ”where's the poop in a Robin's nest?”. https://youtube.com/watch?v=lG7OmThrq5g

Cool video! 🙂 My education for the day 🙂

clj-kondo new release: 2021.06.18 ✨ New - Lint arities of fn arguments to higher order functions (`map`, filter, reduce, etc.) E.g. (map-indexed (fn [i] i) [1 2 3]) will give a warning about the function argument not being able to be called with 2 arguments. - Add map-node and map-node? to hooks API Enhanced / fixed - Disable redefined-var warning in comment - :skip-comments false doesn't override :skip-comments true in namespace config - False positive duplicate set element for symbols/classes https://github.com/clj-kondo/clj-kondo/blob/master/CHANGELOG.md#20210618 Happy linting!

So, I've been experimenting with adding a real prolog in Clojure. It's not yet feature-complete, but as a proof-of-concept, it's working for some examples! https://github.com/mauricioszabo/spock

If there are no solutions to a problem, does it respond with no? That was always one of things I found adorable about Prolog 🙂

(also, please make it work with deps.edn and the CLI 🙂 )

Here's an example of n-queens example :D

@seancorfield hahahaha, not yet 🙂. Currently it returns an empty list only. But I'll handle these cases

> How many Prolog programmers does it take to screw in a light bulb? > No.

BTW, I just saw that there's some confusion on the conversion (keywords translate to prolog atoms, but symbols sometimes become atoms, sometimes become vars).

I think I'll make symbols become atoms all the time, and keywords become vars all the time. This makes more obvious how to unify things for example, and solvers will be less confusing