I need to debug an private function parse-loc failed which is defined in an library kce-clj. When I invoke it in Emacs CIDER, it always has another middleware issue caused an exception. So I have to debug function in plain lein repl, I'm running code:

(with-open [f ( "/home/stardiviner/Documents/learning/Clojure/kindle-export-notes/My Clippings.txt")]
    (kce-clj/extract f "UTC"))

NullPointerException   clojure.string/lower-case (string.clj:217)

Often you can print a full stack trace showing all of the stack frames, each with its own file name and line number. Try (clojure.repl/pst) Sometimes they can be fairly long and contain many lines you do not care about, but find the line that has clojure.string/lower-case (string.clj:217), probably near the beginning of the output (you may need to scroll back), and look at the next line or two for parse-loc.

Does anybody know what continuation means?

It is somehow related to trampoline thingy, but still don't quite get it

@andy.fingerhut I got this output by (pst).

kindle-export-notes.core=> (pst)
NullPointerException
        clojure.string/lower-case (string.clj:217)
        clojure.string/lower-case (string.clj:213)
        kce-clj.core/parse-loc (core.clj:26)
        kce-clj.core/parse-loc (core.clj:23)
        kce-clj.core/parse-cat-loc (core.clj:34)
        kce-clj.core/parse-cat-loc (core.clj:30)
        kce-clj.core/parse-meta (core.clj:50)
        kce-clj.core/parse-meta (core.clj:47)
        kce-clj.core/parse-entry (core.clj:57)
        kce-clj.core/parse-entry (core.clj:53)
        kce-clj.core/lazy-extract/fn--201 (core.clj:66)
        clojure.core/map/fn--5587 (core.clj:2747)
nil

This doesn't give out too much information.

I found how, I redefined that privated function in the library namespace, and add println line before the function result. Then found which line of file caused this problem. Because some lines of file are Chinese, so parsed error.

i’m sure i’ve missed something, but does the manifold library provide an equivalent to core.async’s pipeline-async in the sense of “kick off a bunch of processes that and then collect their results as they complete”? its stream map and reduce seem to wait for each deferred value to resolve before continuing.

or maybe (likely) i’m thinking about this all wrong

the processes would be io-bound and blocking, say uploading files to s3 via amazonica

this toy seems to behave the way i’d like:

@(let [ns (a/to-chan (range 10))
       out (a/chan)]
   (a/pipeline-async
     4
     out
     (fn [n c]
       (a/go
         (a/>! c (a/<! (a/thread
                         (println "start " n)
                         (Thread/sleep (* 100 (rand)))
                         (println "finish " n)
                         n)))
         (a/close! c)))
     ns)
   (s/reduce conj [] (s/->source out)))

but then this other toy seems to go more or less one-at-a-time:

@(let [limit 10
       ns (range limit)]
   (->> ns
     (s/map (fn [n]
              (d/future (println "start " n)
                        (Thread/sleep (* 1000 (rand)))
                        (println "finish " n)
                        n)))
     (s/reduce conj [])))

@clarkenciel have you looked at zip ?

hmm i haven’t, i’ll check it out thanks!

okay now i have

@(let [limit 10
       ns (range limit)]
   (->> ns
     (s/map (fn [n]
              (d/future (println "start " n)
                        (Thread/sleep (* 1000 (rand)))
                        (println "finish " n)
                        n)))
     (s/stream->seq)
     (apply d/zip)))

@clarkenciel right:

@(apply d/zip (map d/success-deferred (range 10)))
(0 1 2 3 4 5 6 7 8 9)

Hi. I'm trying to add levand/heat {:git/url "" :sha "6f2dbba0c055b281e1624b5814fd84c27d64f7bb"} to my deps.edn and I'm getting Error building classpath. Manifest type not detected when finding deps for levand/heat in coordinate ... after the repo is cloned and checked out. Does this mean the included project is missing a deps.edn?

@cristibalan you might also want to try #tools-deps

lein cljsbuild once is stops showing warnings after a couple of times of running that command.

I don't think its random

Does this have anything to do with cacheing perhaps?

are you cleaning in between?

yes, I would assume if a cached artifact is used, you wouldn't get the warning

I did run lein clean

but the warnings still dont come up

does lein know to clean the js artifacts cljsbuild makes?

a common configuration issue is creating a custom target js dir and not adding it to clean-targets

it's not automatic

I don't know. How would I find out?

It looks like we are creating a custom target js dir

did you customize where compiled js goes in cljsbuild? if so you also need to customize clean-targets

warning, that does mean lein will throw away everything in that directory when you clean

Just to make sure we are on the same page. You are talking about :compiler {:output-to "path/to/site.js"}

right

there's also output-dir iirc

How would I customize clean-targets?

lein help sample shows, but it's pretty intuitive

let me give it a go

looks like adding :output-to to :clean-targets vector even works

err, [:cljs-build :compiler :output-to] or something like that

would the vector work if :cljsbuild is set up like this :cljsbuild -> :builds [(which is a vector with a single map)] -> :compiler -> :output-to ?

[:cljsbuild :builds :a-build-name :output-to]

or maybe just hard-code the output-to value instead

Got it! :thumbsup:

My only gotcha is that it now doesn't delete the target directory lol

But I can figure that out

Does anyone has recommendations for referencing environment variables from the project.clj?

@jacob.haag do you mean something like environ? https://github.com/weavejester/environ

Ah that might do it, thanks

sometimes ~(System/getenv "FOO") inside the project.clj works - depends on how much you need

in boot that works for sure, but I don’t want to get into boot vs lein now 😉

yes, the ~ makes sure it works with lein

project.clj is in an implicit syntax-quote

Hi, I am in need of an introductory book for someone with little programming knowledge and none in functional programming. Do anyone have a good indication?

maybe consider “How to Design Programs” by Felleisen + Findler?

depends a lot on your goals of course

It seams a book that would attend my needs, my only concern is it not being exactly clojure. I was thinking about SICP but afraid it would be too dense.

wasn’t there a clojure port of SICP? I don’t know how far it got

http://www.sicpdistilled.com/

I haven't read it since the first edition, but I thought "Programming Clojure" was gentle enough for beginners.