in one file (core.clj) I have
(ns nac.core)
(def bar "something")
And in another file in the same directory, I have
(ns nac.io
(:require [nac.core :as c]))
(defn foo [] c/bar)
Upon evaluation I get an error saying
Unable to resolve symbol: c in this context
So the file is found in the require, but the namespace as I have named it is not.
What am I missing here? Thanks.
Related
I have the following Clojure code in LightTable
(ns exercise
(:require [clojure.string :as str]))
(defn -main
[& args]
(def str1 "Hello world")
(str/includes? str1 "world")
)
When i try to run it i get the following exception:
clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: No such var: str/includes?
Am i importing the library wrong or is something else wrong ?
You're probably using an old Clojure version. includes? was added in 1.8.
I am trying out the function (starts-with?) shown here: https://clojure.github.io/clojure/clojure.string-api.html and when I try to use it I get Unable to resolve symbol: starts-with? in this context error message . I modified my project dependencies too by specifying :dependencies [[org.clojure/clojure "1.8.0"]] but that didn't seem to help.
You may have forgotten to require the namespace ? See the example below:
(ns simple.strings
(:require [clojure.string :as str]))
(str/starts-with? "hello, world" "hello")
; true
I am pulling my hair out trying to resolve the following error:
Exception in thread "main" java.io.FileNotFoundException: Could not locate composer/midi/short_message__init.class or composer/midi/short_message.clj on classpath: , compiling:(events.clj:12:1)
The reference to short-message is in the namespace declaration of events.clj:
(ns composer.ui.events
(:use [seesaw core border chooser])
(:require [composer.midi
[io :as io]
[time :as time]
[player :as player]
[short-message :as short]]))
And here is the namespace declaration of short-message itself in short-message.clj:
(ns composer.midi.short-message
(:require [composer.algorithm.transform :refer :all]
[composer.algorithm.markov.transform :refer :all]
[composer.midi [io :refer :all] [message :as message]]))
short-message is in the same directory as all other files in composer.midi, and yet this seems to be the only one that is resulting in an issue. Indeed, after verifying the target directory in my project, this is the only namespace which doesn't seem to contain a corresponding class file. I thought it could be an error with the code, but if I try to load the file with (load-file "src/composer/midi/short-message.clj") at the REPL I don't have any issues.
Your comment is right. In clojure dashes in namespaces correspond to underscore in filenames. So your file name should be short_message.clj as you found.
I wrote a small namespace to do some database operations and I would like to use it from within another namespace. Normally having the files in the same directory and then doing
(ns program (:require [other-ns :as other]) (:gen-class))
would be all that's necessary. However this doesn't work in Clojure CLR, compiler complains about not knowing about other-ns. So what is the proper method of doing this? Having a seperate assembly for every namespace?
[EDIT] Another example
another.clj
(ns another)
(defn hello [name] (str "Hello " name))
program.clj
(ns program
(:require [another :as a])
(:gen-class))
I load up program.clj in the repl and get this message:
FileNotFoundException Could not locate another.clj.dll or another.clj on load path. clojure.lang.RT.load (d:\work\clojure-clr\Clojure\Clojure\Lib\RT.cs:3068)
I created two files in the same directory filea.clj and fileb.clj. Here's filea.clj:
(ns filea)
(defn hi []
(println "hi from filea"))
Here's fileb.clj:
(ns fileb
(require [filea :as a])
(:gen-class))
(defn -main []
(println "hi from fileb")
(a/hi))
I then changed into the directory where these files live and ran:
C:\temp\multi-ns>clojure.compile fileb
Compiling fileb to . -- 59 milliseconds.
And when I ran it I saw:
C:\temp\multi-ns>c:\Tools\clojure-clr-1.3.0-Debug-4.0\fileb.exe
hi from fileb
hi from filea
Are you using vsClojure or writing your code outside of VS?
I download the clojure 1.2 and clojure-contrib-1.2.0.jar from the download site.
And I found the info about the math functions.
As is shown in the example, I tried to run the code.
(ns your-namespace
(:require clojure.contrib.generic.math-functions))
(println (abs 10))
But, I got the following error, when I run as follows.
CLOJURE_JAR=/Users/smcho/bin/jar/clojure.jar:/Users/smcho/bin/jar/clojure-contrib-1.2.0.jar
java -cp $CLOJURE_JAR:$CLASSPATH clojure.main SOURCE.CLJ
Exception in thread "main" java.lang.Exception: Unable to resolve symbol: abs in this context (hello.clj:4)
at clojure.lang.Compiler.analyze(Compiler.java:5205)
...
at clojure.main.main(main.java:37)
Caused by: java.lang.Exception: Unable to resolve symbol: abs in this context
at clojure.lang.Compiler.resolveIn(Compiler.java:5677)
at clojure.lang.Compiler.resolve(Compiler.java:5621)
at clojure.lang.Compiler.analyzeSymbol(Compiler.java:5584)
at clojure.lang.Compiler.analyze(Compiler.java:5172)
... 25 more
What might be wrong?
Try :use instead of :require
(ns your-namespace
(:use clojure.contrib.generic.math-functions))
(println (abs 10))
10
nil
Require makes the symbol (abs in this case) available, but you'd have to fully qualify it. Use imports the symbol into "your-namespace":
(ns your-namespace2
(:require clojure.contrib.generic.math-functions))
(println (clojure.contrib.generic.math-functions/abs 10))
10
nil