What is the best way to implement user authentication and authorization for a Clojure Luminus application that has a front end developed using Reagent? Can the Spring security filter chain be used?

Do you have a one-liner for listing all namespaces available on the classpath? :thinking_face: Not just those that have been required.

that is not a one-liner 😉

If one wanted to delay require-ing a namespace and using fn's from that namespace, guarded by an if, how would one go about it? My own experiments have shown that just having require inline does not work, as I'm getting ClassNotFoundExceptions around fn's in the namespace I'm delaying loading. I've found https://github.com/clojure-goes-fast/lazy-require which seems to fit my need. Is there a better way to achieve this?

TIL: class and type are two different functions:

(defrecord Hihi [x y z])
(class hihi)
;; => clojure.lang.PersistentArrayMap
(type Hihi)
;; => java.lang.Class

I don't think that's showing you what you think it is

However, it sometimes yield the same results:

(def hihihi {:x 1 :y 2})
(class hihihi)
;; => clojure.lang.PersistentArrayMap
(type hihihi);; => clojure.lang.PersistentArrayMap

in most cases, class and type will give you the same answer - class is just the Java class and type is that but it can be overridden with a metadata tag

user=> (type ^{:type 123} [])
123
user=> (class ^{:type 123} [])
clojure.lang.PersistentVector

Yeah, the documentation of type says: “Returns the :type metadata of x, or its Class if none”. Then it follows that if I supply the record Hihi with a type metadata, type will pick it up.

in your first example above, you capitilized Hihi which is a class name, which resolves to the Java class representing the record (not the hihi record instance)

Oops, I just tried my hypothesis out and it confirmed your explanation.

I'm playing around with Eastwood, I have (def min-part-byte-size (* 1024 1024 5)) and then I use it with (> (.size output-stream) min-part-byte-size) (and I have output-stream defined as ByteArrayOutputStream). eastwood yells about this: boxed-math: public static boolean (long,java.lang.Object). I'm surprised that the def isn't smart enough to know it's a long. can I type-hint the def or do I have to type hint it everywhere it's used?

it's not a long

vars can't point to primitive values so it's being boxed into a Long

you can type hint the def though

although I'm not sure that will help you enough here. this is also the rare case where using :const actually makes sense (assuming you're not altering that var)

user=> (set! *unchecked-math* :warn-on-boxed)
:warn-on-boxed
user=> (def ^:const ^{:tag 'long} min-part-byte-size (* 1024 1024 5))
#'user/min-part-byte-size
user=> (> (.length "abc") min-part-byte-size)
false

even just ^:const might be enough there

thank you for double checking, i appreciate it

Anyone know offhand of a JSON serializer that can, e.g., write :foo/bar as "foo/bar"? clojure.data.json/write[-str] discards namespaces on any instance of clojure.lang.Named, and doesn't appear to have an option to change that behavior.

I vaguely recall seeing a naming convention from the Malli source where some binding names have a question mark prefix like ?foo. I assumed that means that there's some nil punning involved and the value might be nil. Seems like a shorthand maybe-foo. Is that a thing people do? I like it but I might have just made it up in my head 😄 I'm thinking about naming a function time-str->?inst and I'm wondering if that is readable enough.