Vfrdtyky

I'm learning Clojure with 'Clojure for the Brave and True' book and use emacs, cider and leiningen. I've created a project.

lein new app the-divine-cheese-code

Then I've added to source files to the project.

the-divine-cheese-codesrcthe_divine_cheese_codecore.clj
the-divine-cheese-codesrcthe_divine_cheese_codevisualizationsvg.clj

In 'core.clj' I refer to the 'svg.clj' namespace.

the-divine-cheese-codesrcthe_divine_cheese_codecore.clj

(ns the-divine-cheese-code.core)

;; Ensure that the SVG code is evaluated

(require 'the-divine-cheese-code.visualization.svg)

;; Refer the namespace so that you don't have to use the 

;; fully qualified name to reference svg functions

(refer 'the-divine-cheese-code.visualization.svg)



(def heists [{:location "Cologne, Germany"

              :cheese-name "Archbishop Hildebold's Cheese Pretzel"

              :lat 50.95

              :lng 6.97}

             {:location "Zurich, Switzerland"

              :cheese-name "The Standard Emmental"

              :lat 47.37

              :lng 8.55}

             {:location "Marseille, France"

              :cheese-name "Le Fromage de Cosquer"

              :lat 43.30

              :lng 5.37}

             {:location "Zurich, Switzerland"

              :cheese-name "The Lesser Emmental"

              :lat 47.37

              :lng 8.55}

             {:location "Vatican City"

              :cheese-name "The Cheese of Turin"

              :lat 41.90

              :lng 12.45}])



(defn -main

  [& args]

  (println (points heists)))

the-divine-cheese-codesrcthe_divine_cheese_codevisualizationsvg.clj

(ns the-divine-cheese-code.visualization.svg)



(defn latlng->point

  "Convert lat/lng map to comma-separated string" 

  [latlng]

  (str (:lat latlng) "," (:lng latlng)))



(defn points

  [locations]

  (clojure.string/join " " (map latlng->point locations)))

Here is the project's entire dir structure.

the-divine-cheese-code              

the-divine-cheese-code.gitignore               

the-divine-cheese-code.hgignore                

the-divine-cheese-code.nrepl-port              

the-divine-cheese-codeCHANGELOG.md             

the-divine-cheese-codedoc              

the-divine-cheese-codedocintro.md             

the-divine-cheese-codeLICENSE              

the-divine-cheese-codeproject.clj              

the-divine-cheese-codeREADME.md                

the-divine-cheese-coderesources                

the-divine-cheese-codesrc              

the-divine-cheese-codesrcthe_divine_cheese_code               

the-divine-cheese-codesrcthe_divine_cheese_codecore.clj              

the-divine-cheese-codesrcthe_divine_cheese_codevisualization             

the-divine-cheese-codesrcthe_divine_cheese_codevisualizationsvg.clj             

the-divine-cheese-codetarget               

the-divine-cheese-codetargetdefault               

the-divine-cheese-codetargetdefaultclasses               

the-divine-cheese-codetargetdefaultclassesMETA-INF              

the-divine-cheese-codetargetdefaultclassesMETA-INFmaven                

the-divine-cheese-codetargetdefaultclassesMETA-INFmaventhe-divine-cheese-code             

the-divine-cheese-codetargetdefaultclassesMETA-INFmaventhe-divine-cheese-codethe-divine-cheese-code              

the-divine-cheese-codetargetdefaultclassesMETA-INFmaventhe-divine-cheese-codethe-divine-cheese-codepom.properties

the-divine-cheese-codetargetdefaultrepl-port             

the-divine-cheese-codetargetdefaultstale

the-divine-cheese-codetargetdefaultstaleleiningen.core.classpath.extract-native-dependencies

the-divine-cheese-codetest

the-divine-cheese-codetestthe_divine_cheese_code

the-divine-cheese-codetestthe_divine_cheese_codecore_test.clj

When I run the project with 'lein run' it executes successfully. However, when I open the core.clj file with emacs/cider and try to compile it, I get classpath error.

CompilerException java.io.FileNotFoundException: Could not locate 

the_divine_cheese_code/visualization/svg__init.class or 

the_divine_cheese_code/visualization/svg.clj on classpath. Please check 

that namespaces with dashes use underscores in the Clojure file name., 

compiling:(c:/temp/the-divine-cheese-code/src/the_divine_cheese_code/core.clj:2:1)

CIDER compiles sources sucessfully if I put them in the same directory (changing namespace correspondingly).

(ns the-divine-cheese-code.core)

(require 'the-divine-cheese-code.svg)

(refer 'the-divine-cheese-code.svg)



(def heists [{:location "Cologne, Germany"

    ...

So maybe the issue is dealt with OS. I use Windows 7, which is not primary OS for Emacs/CIDER.

After some experimenting I found that the CIDER works without :refer

(ns the-divine-cheese-code.core

  (:require [the-divine-cheese-code.visualization.svg]))

This looks like a CIDER bug and 'lein run' predictably gives error in this case.
If I make it the right way

(ns the-divine-cheese-code.core

  (:require [the-divine-cheese-code.visualization.svg :refer :all]))

the CIDER now gives another error:

Caused by java.lang.IllegalStateException

latlng->point already refers to:

#'the-divine-cheese-code.svg/latlng->point in namespace:

the-divine-cheese-code.core

Would suggest to use the options provided by the ns macro instead of naked require and refer statements - this is the recommended way of doing imports/requires in Clojure and most of the tooling is written with this way of managing namespaces in mind. Even if the below code still doesn't work in CIDER, it will be easier to diagnose it:

;; the-divine-cheese-codesrcthe_divine_cheese_codecore.clj



(ns the-divine-cheese-code.core

  (:require [the-divine-cheese-code.visualization.svg :refer :all]))



(def heists ...)



(defn- main ...)