hi, can't find it anywhere, this errors out

(defn po [vol {:keyA [id name age] }])

but if i replace :keyA with :keys , it doesn't

https://clojure.org/guides/destructuring

Is there a term people use to describe the different "maps of expected shape" in their code? Ie, something which would be described by s/keys in spec. Clearly "type" isn't a great word to use, though this is how I think of them in my head. "keyspec"? hijack the word "struct"? As in "Here are the various <type-things> my app uses, and the possible keys in each of them: ..."

schema

Entities

thanks for the input

wouldn't entities describe the instances better?

Sorry, I misunderstood your question - so yes, entities would work better here (and they have to comply with a schema ;-))

no you were right I meant the way to describe the classification of the instance not the instance itself

schema might be good. Just trying to work out if i have precisely a spec.alpha2 schema here. And also if myapp.schema.person and myapp.schema.company sounds right

I often think of “entity” as a definition

The word "type" is the one I have encountered the most so it would make sense to me. But I find more helpful to think in terms of "set of keys" that entities can use or not, rather than type. So entities are not limited to one type.

you could go with “model” but eh

because also i have things in my app that would be described by a spec.alpha2 schema but are not one of these things

an instance of an entity is usually a map :P

ok gotcha that makes sense when you put it that way

I think "entity" has more to do with the idea of identity than schema or type: "a thing with distinct and independent existence."

Yeah that was my initial thought. "I am an entity. I am a person. Person is my <type/class/category>"

Yes, <type/class/category> are the most common terms for this idea so any of those would work. But you're not just a person, you can have many roles, so that's why it is more useful to think in terms of roles (or sets of keys) rather than types.

type/class/category sounds either too abstract, too closed or both ¯\(ツ)/¯

(to me)

“entity description” perhaps? but that’s rather long

I think a schema or spec that describes an entity is quite different than a type or class that describes some implementation detail, i think is where I get hung up

"type" is used a lot in data modeling to represent exactly this "class" is used in RDF schema and ontologies (OWL)

but we live next to Java/JS land, which have different meanings for those

Hi, is there a non-blocking io (and specifically reading from file) in Clojure?

i see that slurp is definitely blocking

Java has a variety of blocking and nonblocking io apis, which are all usable from Clojure

i would expect that Clojure will have a fn that reads from a file in a non-blocking way and return a channel. I can write one my self (in about 5 lines of code) but isnt there one?

Clojure in general does not provide wrappers around things that can be used directly via java interop in the jdk (so, no there isn't one)

so why slurp is part of clojure ?

slurp is a helper function that does a frequently used combination of actions

by channel do you mean core.async?

I presume java.nio.channels.Channel

ah thanks

you can get a channel with something like (.getChannel (java.io.RandomAccessFile. "afile.txt" "r"))

this is fine, but I would like a more idiomatic Clojure solution for this - i.e., something that returns a core.async Channel. why not have something like async-slurp in core.async ? sounds like a common use case for io intensive apps.

interop is idiomatic

and async is a library

Hi... I think I'm compiling clojure with :direct-linking true in *compiler-options*; but looking at my byte code (disassembled in IntelliJ), I still seem to have a lot of Vars and indirection. Would that be expected?

yes, dynamic vars cannot be inlined and there are plenty of those

Depends where you are seeing them

If I understand correctly what that is, Criterium is probably a Clojure equivalent: https://github.com/hugoduncan/criterium It has code that explicitly tries to first run some code enough times that the Java JIT compiler will likely kick in and create a native machine code version of your code before starting its measuerements.

question: I have a function that performs "transducing" over single element, how should I name it? code:

(defn ??? [xf f v]
  (let [rf (xf (completing #(f %2)))]
    (rf (rf nil v))))

(??? (map-indexed vector) str :a)
=> [0 :a]
(??? (map-indexed vector) println :a)
;; prints [0 :a]
=> nil
(??? (comp (filter int?) (map-indexed vector)) println :a)
;; does not print anything because :a is not an int
=> nil

meta question: is this question a good fit for https://ask.clojure.org/ ?

That sort of feels like it violates expectations around reduction/transduction to me... It's almost the same as transduce with the last arg wrapped in [ ]...

yeah, I now realized that it's not really a good ???duction, because it completely disregards accumulator

although it's exactly what is needed for my use case

...in a way that (transduce xf f [v]) is not? Presumably in the (f) case to create the accumulator?

f will receive 2 args: accumulator and item, and in my case I don't care about accumulator, just performing side effects on each item

So maybe it's a runduction! :rolling_on_the_floor_laughing:

😄

is this the same as run!?

is there a core equivalent of something like #(or % 0)?

I guess (fnil identity 0) - which is not much concise

I think fnil is correct, but I probably wouldn't use it on identity

so what’s the better way of doing something like this: (comp not zero? (fnil identity 0) util/parse-int)? parse-int return nil if can’t parse

(comp not (fnil zero? true) util/parse-int)

#({nil 0 false 0} % %) - returns arg if not nil or false, otherwise 0

but also not sure if I would use a hof like comp for this yeah

edn file trying to add sonatype and some dependencies that should be on there

when i use clj to run my project with these dependencies, it complains that it can't find them on Maven Central. how can i force a specific dependencey to be fetched from sonatype (which i am adding in that file) ?

I'm not sure what sonatype is but you can add external repos under the mvn/repos key. For example: :mvn/repos {"Sonatype" {:url ""}}

are you sure it's org.bitcoin-s and not org.bitcoins

@ysangkok based on browsing that repo, it looks like you are specifying the version string incorrectly - eg https://oss.sonatype.org/content/repositories/snapshots/org/bitcoin-s/bitcoin-s-secp256k1jni/0.1.0+45-91633375-SNAPSHOT/bitcoin-s-secp256k1jni-0.1.0+45-91633375-SNAPSHOT.pom

that pom suggests the version string 0.1.0+45-91633375-SNAPSHOT which matches the date you specified, but doesn't include it in the version

aaah thanks! @noisesmith... i couldn't figure out how to browse sonatype, how did you do that? just manually adapt an URL from a different package? and remove elements from the end?

I started at https://oss.sonatype.org/content/repositories/snapshots/ and browsed from there

is there some reason you're using a snapshot?

there is a released 0.1.0

the release should be newer than the snapshot

oh, i didn't realize. i wanted to use the snapshot because this is a one-off anyway and i don't know how stable that project is, and i would wanna report bugs based on master

I'd just use {:mvn/version "0.1.0"}

then you don't need the special repo either, central is included automatically

@alexmiller how can the release be newer than the snapshot? https://github.com/bitcoin-s/bitcoin-s/tree/v0.1.0 says the last commit is from may but the full version string of the snapshot says 201906, which should be june

yeah, I was just looking at that. that's very weird.

my guess would be a ci process continuing to build something off the snapshot version

like the snapshot base version didn't get updated after the release build

what I'm saying is, someone on the internet is wrong

aaaah yeah ok, i didn't even consider that a problem. i always thought if a version contains SNAPSHOT, you basically cannot trust its version number?

but even if you were using a snapshot, you shouldn't pull in a specific timestamp version like that. The snapshot version is a "virtual" release and maven will map to the latest timestamp. So, you'd just want to use {:mvn/version "0.1.0-SNAPSHOT"}