hello all, is there any way to hook a function and insert a delay between all others functions inside it?

often when i’m using core.async, after restarting some processes or after letting them run for a while, I can’t see my log output anymore in my repl and can’t tell if my core.async processes are just not running or if the logs have just disappeared, is this a common problem and if so how do people deal with it or is it a sign of an underlying problem, too many go loops perhaps? When I start a fresh REPL, whether I run (println "TEST") or (go (println "TEST")), I can see “TEST” in my repl, but after running for a while (println "TEST") will show and (go (println "TEST")) will not.

@jdkealy core.async uses a small, fixed thread pool I believe so it's entirely possible you're overwhelming it, if I'm understanding you correctly.

I need help with macros. I’d like to create a macro defnmy similar to defn but that creates a function whose name is transformed by a function supplied to the macro. Example of usage:

(defnmy FOO clojure.string/lower-case [x]
    (inc x))

(defmacro defnmy [name fn args body]
  (let [n (symbol ((resolve fn) name))]
    `(defn ~n ~args ~body)))

@viebel Why would you want to avoid resolve?

1. I’d like the macro to work on self-hosted cljs 2. Understanding what macros can and cannot do

The macro is passed a bare symbol. You have to turn that into an actual function, in order to apply it to the symbol passed in. Not sure how else you would do that?

(I don't know anything about cljs so I don't know what restrictions it places on macros)

I guess I'd also ask why you'd want a macro that is passed both a symbol and the (symbol) name of a function that is applied to it? If you're passing both, why can't you just figure out what the function name should actually be? Is this part of some code generation thing?

(also, if you're going to imitate defn what about docstrings and attr-maps etc?)

Yes, I am trying to make this library https://github.com/clj-commons/camel-snake-kebab self-host compatible and it has this defconversion macro https://github.com/clj-commons/camel-snake-kebab/blob/master/src/camel_snake_kebab/internals/macros.clj#L21

Sorry, no idea.

I guess I wish cljs didn't have these limitations?

Fixing the cljs compiler seems like a better goal to me.

Ok. Trying on #clojurescript

why not eval instead of resolve ? it will work with any function definition, it will resolve the var with symbols, and it should work on self-hosted

Hi, This is a question i did post on crux and ring. But the problem seems more related with deploying a war (lein ring uberwar) on tomcat. I have an init function that start a crux node but tomcat freeze once deployed. It seems to be a problem with threads but i am lost here. I wonder if someone has exeprienced this or can give me some advices ? Many thanks

SEVERE [localhost-startStop-2] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [user-settings-webapp] created a ThreadLocal with key of type [java.lang.ThreadLocal](value [java.lang.ThreadLocal@8117ba6]) and a value of type [io.netty.util.internal.InternalThreadLocalMap](value [io.netty.util.internal.InternalThreadLocalMap@6684e4af]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.

Is there any way to override a particular defmethod in an external library? Or will I have to fork said library?

you can override it normally as you would do for your own codebase

(ns external)

(defmulti foo ...)

(defmethod foo :x ...)

;; your code
(ns my-code
  (:require [external :as e]))

(defmethod e/foo :x ...)

Oh okay, thanks! I tried doing something like that but failed… I guess I just got confused somehow 🙂

@leonoel suggested above to replace (resolve sym) by eval (something like (eval `('var sym))`` https://clojurians.slack.com/archives/C03S1KBA2/p1596091177157900 And indeed that’s the way to do it in Self hosted Clojurescript as explained by @mfikes in https://clojurians.slack.com/archives/C03S1L9DN/p1596132644159300 Now my question is: is that acceptable to use eval instead of resolve in JVM Clojure for this use case?

@viebel If the function being passed is public, you can indeed further simplify as Leonoel suggested, and just evaluate the function symbol (with no worries about triggering private var access analyzer warnings)

(defmacro defnmy [name fn args & body]
  (let [n (symbol ((eval fn) (str name)))]
    `(defn ~n ~args ~@body)))

Indeed simpler. The question remains: is that acceptable to use eval in Clojure code when we could use resolve instead?

Does clojure.spec work with string keys? (s/conform (s/keys :req-un ["foo"]) {:bar 1}) => {:bar 1}

doc for (doc s/keys)

Creates and returns a map validating spec. :req and :opt are both
  vectors of namespaced-qualified keywords. The validator will ensure
  the :req keys are present. The :opt keys serve as documentation and
  may be used by the generator.

:req-un seems like something that only make sense with things that could be namespaced (and clearly strings cannot be)

@deadghost I am not 100% sure, but my hunch is that to spec a data structure with non-keyword keys, your best bet is to have a conversion function that results in keyword keys, and spec that

I don't see anything about specific keys that aren't keywords in the spec guide at least

(there 's map-of to describe eg. map of string to int)

the attribute parts of spec do not work with string keys

keywordizing first is one option and probably the best if you're looking to lean on those aspects of spec

in some cases, you may be able to make do with map-of or by treating a tuple as an s/coll-of an s/or of various s/tuples describing key/value pairs

why this doesn’t work (s/def ::quantity (s/and number? pos? (complement (some-fn Double/isInfinite Double/isNaN)))) Unable to find static field: isInfinite in class java.lang.Double but this works (s/def ::quantity (s/and number? pos? #(not (Double/isInfinite %)) #(not (Double/isNaN %)))) How to interop this correctly with some-fn? --- PS (s/def ::quantity (s/and number? pos? (complement #{##Inf ##-Inf ##NaN}))) ^ This is probably the nicer one. Does it?

some-fn takes functions

you were passing it values

I think you can do this more simply with https://clojure.github.io/spec.alpha/clojure.spec.alpha-api.html#clojure.spec.alpha/double-in though

(s/def ::quantity (s/double-of :min 0.0 :infinite? false :NaN? false))

the Inf / NaN stuff are only double values so I'm assuming you want doubles. if you want multiple number types, well why? :)

(s/def ::foo (s/with-gen (s/and string? (complement clojure.string/blank?))
                           (partial gen/fmap (fn [_] (rand-nth ["foo" "bar"])) (s/gen string?))))

#{"foo" "bar"} as your spec

but this will also accept only “foo” and “bar”. This is not what I want. I want it only to generate examples for tests.

(s/with-gen your-predicate #(s/gen (s/spec #{1 2 3})))

are folks generally using schema for rest apis in (for example) compojure? i thought it would be mostly spec by now, but most of the examples i find are using schema. is there a newer (well documented) way to build rest apis with clj these days? (i haven’t done it in a couple years, looking to get back into it)