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
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.
clojure version: 1.8.0
leiningen version: 2.7.1
jdk version: 1.8.0_101
When I require a library, say reagent(has added in the project dependencies), in the lein repl:
user=> (require '[reagent.core :as r])
nil
The output is nil, which I think it means success. But when I use the r,say (r/atom 3), the repl throw an error says:
CompilerException java.lang.RuntimeException: Unable to resolve symbol: r in
this context, compiling: (/private/var/folders/_y/n3ym4ftj2ld9tl471g_kcv_00000gn/T
/form-init1002540725014588615.clj:1:4923)
That seems strange.
Anyone has some idea?
By the way, I can require java and clojure library.
Probably you are trying to use ClojureScript library: reagent within the Clojure REPL. Finding the cause to error is not that useful since Clojure and ClojureScript are suppose to run in very different environments, JVM and JavaScript respectively. But same attempt will succeed in ClojureScript context.
As a test, create a ClojureScript project based on figwheel template.
lein new figwheel rtest
cd rtest
Add the regent dependency in project.clj
:dependencies [[org.clojure/clojure "1.8.0"]
[reagent "0.6.0"] ; only add this line
Run the project
rlwrap lein figwheel
You will be connected to the browser repl automatically. Otherwise browse to http://localhost:3449/index.html to get connected.
Now you can retry what you did.
cljs.user=> (require '[reagent.core :as r])
nil
cljs.user=> (type r/render-component)
#object[Function "function Function() { [native code] }"]
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.
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'm feeling slightly silly here, but I can't get Clojure Hello World to compile.
Directory structure:
hello-world/
clojure-1.1.0.jar
build/
classes/
src/
test/
hello.clj
hello.clj:
(ns test.hello
(:gen-class))
(defn -main [& args]
(println "Hello" (nth args 0)))
Interaction:
$ cd hello-world
[hello-world]$ java -cp ./clojure-1.1.0.jar:./build/classes:./src clojure.main
Clojure 1.1.0
user=> (require 'test.hello)
nil
user=> (test.hello/-main "there")
Hello there
nil
user=> (compile 'test.hello)
java.io.IOException: No such file or directory (hello.clj:2)
user=> *compile-path*
"classes"
user=> (doseq [p (.split (System/getProperty "java.class.path") ":")] (println p))
./clojure-1.1.0.jar
./build/classes
./src
nil
So I can load and call the file from the REPL, but it doesn't compile.
According to clojure.org, compilation needs
namespace must match classpath-relative file path - check
*compile-path* must be on the classpath - check
:gen-class argument to the ns form - check
I found this post from a year back, as far as I can tell I'm doing exactly the same, but it doesn't work.
What am I missing?
System: OS X 10.6, Java 1.6.0, Clojure 1.1
Got it, there's a fourth requirement:
*compile-path* is resolved relative to the JVMs working directory, normally the directory where java is started. Or by REPL: (System/getProperty "user.dir"),
So this works:
user=> (set! *compile-path* "build/classes")
"build/classes"
user=> (compile 'test.hello)
test.hello
Why you don't use Leiningen? It's much easier to use it, than compile code manually. You can use my article about it as introduction...
To run clojure file
clojure filename.clj