@seancorfield The cljs compiler (boot_cljs) is somehow not able to locate that namespace. Is it part of some package one must require in build.boot (this is for a CLJS project)?

@seancorfield Thanks, good to know!

I’m trying to require a macro from sablano into a cljc file. It loads in CLJS but not in CLJ

(ns app.ui
  (:require [rum.core :as rum]
            [sablono.core :refer-macros [html]]))

It keeps saying that it can’t resolve html

does [sablono.core :as html :refer-macros [html]] result in anything different?

No.

you could try

#?(:cljs
 :require-macros [sablono.core :as [html]])

In the namespace foo-bar.core I've got (defrecord Baz [left right]). In another namespace foo-bar.core-test I want to check for membership using (instance? Baz a). I've added the import to the ns macro (ns foo-bar.core-test (:import [foo_bar.core Baz])), But the check with instance? fails because a is a foo_bar.core.Baz, not a Baz. Is there a way to import a record type so I don't have to specify the fully qualified name?

@vinai huh, that is suprising... Baz should map to foo_bar.core.Baz when imported as you have. how is a defined?

@mtkp a is defined by a factory function in foo_bar.core

i have a list of files stored in an atom like this:

user> (take 5 @g)
(#object[java.io.File 0x593890b8 "dest/file0"] #object[java.io.File 0x33e303d8 "dest/file1"] #object[java.io.File 0x2fb5d0a2 "dest/file10"] #object[java.io.File 0x5ea35c6d "dest/file100"] #object[java.io.File 0x4303ba51 "dest/file1000”])

user> (delete-file (str (.getParent (first @g)) "/" (.getName (first @g))))
true

Why not just call .delete on the File object?

(.delete (first @g))

perfect!

@mruzekw: :refer-macros is a CLJS-only construct. From CLJ you'd just use :refer [html]. For CLJC, you might want a reader conditional as @carly suggested

oh wait, can .delete be passed in to a higher order function like map?

Thanks @timgilbert

It might be simpler to just do :require [sablono.core :as s] ... (s/html [:head ...]), with more recent versions of ClojureScript the CLJS compiler will figure out what things are macros and pull them in on :require

Getting macros working in CLJS still seems like a bit of a black art though. You might find this useful if you're mixing macros and CLJC: https://github.com/cgrand/macrovich

i found:

(map #(.delete %) (take 5 @g))

@mfm See also memfn

I am trying to understand how class loading works.. I am using clojure.string in one of my functions and somehow the code throws runtime error 'java.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils’ SO looks like ‘org/apache/commons/lang/StringUtils’ class is not found.. What is the right way to fix this?

Should I include org.apache.commons.lang.StringUtils in project.clj?

That’s… weird. clojure.string has no direct dependency on anything other than java and clojure itself

Perhaps you could paste the code in question?

I knoww…but I started coming across it only after I added this code

Do you have something like (ns foo (:require [clojure.string :as string])) at the top of your file @payal? Maybe somehow your editor tried to automatically import a different string library or something?

wohoo yes I do

But why will that import different string library?

Very odd, I'm not sure

No, the stuff I posted above should be correct

But I was thinking sometimes IDEs can auto-insert other classes for you and it's easy to get the wrong one sometimes

But you'd see it in your code

If you're using leiningen you could try running lein deps from your project to make sure your local repository has the correct dependencies

hmm okay let me do that .. by that you mean there should be no package other than clojure.string which lein is puling right?

Yeah

How are you running your code?

Basically if you have a leiningen project, all the classes that are loaded when you run your code should come from the :dependencies key in your project.clj

right

You can run lein deps :tree to view the whole tree of jar files that lein will pull in based on that list

And lein deps by itself will try to download any files that you don't have locally

thanks I was looking for this command because lein deps does not shoe downloaded packages

If nothing else you can start from scratch by deleting ~/.m2/repository and then lein deps again. Not sure about the exception you're getting

But yeah, just with the code you posted I wouldn't expect it to require the apache string libraries

yeah i am also not convinced that it would require StringUtils, but then it is failing with that exception so not sure…thanks for the help though 🙂

is there a way to find out what protocols something implements?

like given an object get back a set of protocols

did you go through this https://clojure.github.io/clojure/clojure.reflect-api.html?