here is a very specific question re the clojure class path and lein / emacs
lets say I'm working with a project and have a repl with clojure-jack-in. I need to add a new dependency to this project, is there any way to run lein deps and then be able to use the downloaded .jar in the open repl right away (possibly a repl command?)?
right now whenever I need to add a new dependency I need to reset the swank/slime connection for it to become visible in the classpath.
Thanks
I see three options:
Use Jark to start a REPL on a JVM that can handle new jar files at runtime (http://icylisper.in/jark/index.html)
add-classpath method in clojure (breaks sometimes ... http://groups.google.com/group/clojure/browse_thread/thread/43a413ae55ed25d0)
Write your own code to add the new jar file (http://groups.google.com/group/clojure/browse_thread/thread/0095ea6e918c430e)
Related
I am using lein repl without a project so there is no project.clj.
I am running Leiningen 2.8.1 on Java 1.8.0_191 OpenJDK 64-Bit Server VM.
When I require a Clojure dependency that I assume should just work - like clojure.data.json - I notice that it is not in my .m2 directory. Is that why I am getting a FileNotFoundException Could not locate clojure/data/json__init.class or clojure/data/js
on.clj on classpath? I can't find my other Clojure dependencies there either so I don't know where they reside and if this dependancy should be in .m2 or not.
I understand the error message but without knowing its location or even knowing how to properly add it to the CLASSPATH for the REPL to see it, I remain stuck.
Is this a dependency that I still need to install? If so, how do I install it without going through a project?
I don't understand the JVM as I am new to it, so add a little extra information in your answer.
I have looked at this, this, this, this and this. I don't know if I am overlooking anything so your help will really be appreciated.
I am using lein run without a project so there is no project.clj.
If you're using Leiningen, this'll be much easier if you create a project.clj file that declares your dependencies. Leiningen will read project.clj and handle fetching any missing dependencies to your local Maven repository, and add them to your classpath when you start your REPL/application. (lein run doesn't work for me in a directory without a project.clj; I get an error: No :main namespace specified in project.clj.. Did you mean lein repl?)
When I require a Clojure dependency that I assume should just work - like clojure.data.json - I notice that it is not in my .m2 directory.
clojure.data.json doesn't ship with Clojure — it's a separate dependency that must be fetched and added to your classpath in order to use it. The classpath tells the JVM where to look when it loads class files. Leiningen will do both of these things for you if you declare the dependency in project.clj:
:dependencies [[org.clojure/clojure "1.10.0"]
[org.clojure/data.json "0.2.6"]]
You can also use the lein deps command if you only want to fetch dependencies.
You can create a new/blank Leiningen project with lein new project_name_goes_here. It will have a project.clj with a few boilerplate entries and a :dependencies key where you can declare dependencies.
I understand the error message but without knowing its location or even knowing how to properly add it to the CLASSPATH for the REPL to see it, I remain stuck. Is this a dependency that I still need to install? If so, how do I install it without going through a project?
You could manually download it from the internet, then manually add its path to your classpath, but if you're already using Leiningen it's much easier to add a line to a project.clj file and have Leiningen handle this for you.
If using a project.clj file w/Leiningen isn't an option, there are other ways to use Clojure and resolve dependencies/build a classpath at runtime. Boot accommodates this workflow, you can use Leiningen like this with a little added effort, as well as the newer tools.deps tooling. There are examples of each in this ClojureVerse thread, but note that some of these approaches are doing essentially the same thing as declaring the dependency in a file — instead declaring them as CLI arguments.
For example, using Clojure CLI tooling:
$ clj -Sdeps "{:deps {org.clojure/data.json {:mvn/version \"0.2.6\"}}}"
Clojure 1.9.0
user=> (require '[clojure.data.json :as json])
nil
user=> (json/write-str {:foo "bar"})
"{\"foo\":\"bar\"}"
user=> (System/getProperty "java.class.path")
"src:
/Users/me/.m2/repository/org/clojure/clojure/1.9.0/clojure-1.9.0.jar:
/Users/me/.m2/repository/org/clojure/data.json/0.2.6/data.json-0.2.6.jar:
/Users/me/.m2/repository/org/clojure/spec.alpha/0.1.143/spec.alpha-0.1.143.jar:
/Users/me/.m2/repository/org/clojure/core.specs.alpha/0.1.24/core.specs.alpha-0.1.24.jar"
You could create a deps.edn file containing {:deps {org.clojure/data.json {:mvn/version \"0.2.6\"}}} in the same directory, and clj would read that, resolve the dependencies if necessary, and build the classpath accordingly.
This is a great opportunity to use lein try. Once you add it to your ~/.lein/profiles.clj, you'd simply run: lein try org.clojure/data.json and you'll be greeted with a running REPL with that dependency just a require away.
I just installed leiningen and am following the tutorial on how to start. I typed
lein new my-stuff and then corrected the project.clj file as per the instructions. Then I type lein repl and it pulls up the repl fine.
The next step is to type
(require 'my-stuff.core)
This is where I get
FileNotFoundException Could not locate my_stuff/core__init.class or my_stuff/core.clj on classpath: clojure.lang.RT.load (TR.java:432)
I have tried looking at my classpath, but everything looks alright.
lein classpath
C:\Users\Sarah\leiningen\test;C:\Users\Sarah\leiningen\src;C:Users\Sarah\leiningen\dev-resources;C:\Useres\Sarah\leiningen\resources;C:\Users\Sarah\leiningen\target\classes;C:\Useres\Sarah\.m2\repository\org\clojure\clojure\1.4.0\clojure-1.4.0.jar
Any help would be great!
I suspect that the problem here is stemming from your choice of project name. Although you can create Clojure namespaces with hyphens in them, the corresponding physical files and directories need to have the hyphen replaced with an underscore.
As you are just experimenting, the easiest thing for you to do would be to start again with a different project name: try lein new mystuff for example.
If you want to press on with my-stuff then try renaming the src\my-stuff directory to src\my_stuff and doing the same for test\my-stuff if it exists.
To be honest, I'm a little surprised that Leiningen has got this wrong, so there may be something else at work here, or you might just be using an old version of Leiningen.
I setup emacs slime/clojure as written here.
When I run (doseq [p (.getURLs (java.lang.ClassLoader/getSystemClassLoader))] (println (.getPath p))) to get classpath, I get the following.
/Users/smcho/.swank-clojure/clojure-1.1.0-master-20091202.150145-1.jar
/Users/smcho/.swank-clojure/clojure-contrib-1.1.0-master-20091212.205045-1.jar
/Users/smcho/.swank-clojure/swank-clojure-1.1.0.jar
How can I add classpath for emacs/slime for clojure?
The procedure differs depending on whether you are using slime-connect to start slime (by connect to a remote swank server, created with lein swank, for example) or you are starting slime using M-X slime.
If you're using slime-connect, you'll need to modify the classpath of the java process that is running the swank server. If you're starting the swank server using lein swank, simply add the jars you want to be part of your classpath to the project's lib directory.
On the other hand, if you're starting slime using M-X slime, the following elisp code will do the magic for you (just place it in your ~/.emacs file).
(eval-after-load "swank-clojure"
'(progn
(add-to-list 'swank-clojure-classpath
"/Users/smcho/.clojure/")
(add-to-list 'swank-clojure-classpath
"/Users/smcho/.clojure/blah.jar")))
This will add /Users/smcho/.clojure/ and /Users/smcho/.clojure/blah.jar to the classpath. (Please note that you'll either need to restart emacs or reload the .emacs file: type M-X load-library and then type .emacs on the next prompt.)
I believe the advised way to fire up a clojure reple nowadays is to use lein swank, and use \M-x slime-connect. See http://github.com/technomancy/leiningen/ for a detailed description of this tool.
Using leiningen, you can configure your project using a configuration file, project.clj. On this file you may require remotely (maven-)published jars, and by running lein deps you will get a "lib" directory with all the jars. Since the lein swank command uses that directory as a classpath, all you have to do is to add your jars to that directory.
That said, if you're still using \M-x swank-clojure-project, it will also detect your jars under that directory.
However, if you're just using a plain \M-x slime to fire a clojure repl, then I think there's no "clean" solution (aside from adding the path to your global environment's $CLASSPATH or to use some elisp voodoo - like the one in seh's answer - to change the java vm command arguments. But I believe this is only intended to do some quite basic experiments, and shouldn't be used for any project-based work (exactly for this reason!)
If you're willing to hard-code the list of Jar files, this Emacs Lisp form should suffice:
(let ((base-path "/Users/smcho/.swank-clojure"))
(setq swank-clojure-classpath
(append
swank-clojure-classpath
(mapcar (lambda (d)
(expand-file-name d base-path))
'("clojure-1.1.0-master-20091202.150145-1.jar"
"clojure-contrib-1.1.0-master-20091212.205045-1.jar"
"swank-clojure/swank-clojure-1.1.0.jar")))))
That takes your list of Jar files and adds them to the variable swank-clojure-classpath. Note that this form must be evaluated by Emacs, not SLIME's Swank. It's used by Emacs to start up the Java process that will run Clojure and Swank within it.
There are more elaborate ways to set up the class path for a project, such as including Maven-style paths below a designated project root directory.
For some reason I can't get clojure REPL working with jline, what i did was git clone the clojure repository off github then run ant to build it, then i download jline-0.9.94.jar to the directory with clojure.jar, then run the following command:
java -cp jline-0.9.94.jar:clojure.jar jline.ConsoleRunner clojure.main
And get the following errors:
Exception in thread "main" java.lang.ClassNotFoundException: clojure.main
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:317)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:375)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at jline.ConsoleRunner.main(Unknown Source)
Here are the files in my current directory:
vvshs-macbook-2:clojure vvsh$ ls
build.xml clojure-sources-1.2.0-master-SNAPSHOT.jar epl-v10.html src
classes clojure-sources.jar jline-0.9.94.jar test
clojure-1.2.0-master-SNAPSHOT.jar clojure.iml pom-template.xml
clojure-slim-1.2.0-master-SNAPSHOT.jar clojure.jar pom.xml
clojure-slim.jar doc readme.txt
vvshs-macbook-2:clojure vvsh$
I got the same error on clojure 1.1 and lein repl(it seems lein maintain its own version of clojure).
By the way, this is on mac ox 10.5.8
java version "1.5.0_24"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_24-b02-357-9M3165)
Java HotSpot(TM) Client VM (build 1.5.0_24-149, mixed mode, sharing)
Anybody know what's wrong and how to fix it? As I really want to get lein repl working to start a project.
I solved the same problem today by removing a redundant jline*.jar from /Library/Java/Extensions, leaving just one jline installation in CLASSPATH.
Longer explanation: I was trying to build labrepl, which installs all its dependencies in subdirectory lib, but I had previously set up jline by copying the .jar file to /Library/Java/Extensions. Apparently, java.lang.ClassLoader couldn't handle two installations of jline, and as long as there were ones available in two places, the command line starting a Clojure REPL would fail finding the latter one of classes jline.ConsoleRunner and clojure.main, depending on the order they were given to the java command.
I hope this helps.
see my alternative instructions for install on my fork:
http://github.com/jedschneider/leiningen
I sent a pull request to update the readme, but didn't get a response on it. once you have lein installed, you can put the bin/leiningen.sh in your ~/bin and call it anywhere. i put a shortcut on my .bash_profile
alias lein="~/bin/leiningen.sh"
and then call lein repl to launch a shell
also checkout the labrepl which is a great learning tool.
http://github.com/relevance/labrepl
Your java ... command looks fine, I'd double check if all the jars are where you think they should be (and that they are the jars you think they are, i.e. clojure.jar is actually the one you built locally and not some super-outdated one).
If you want to use Leiningen for lein repl, that's possible too. Note that it isn't accurate to say that it "maintains its own version of Clojure"; Leiningen is a build tool, used as part of a project-oriented workflow, and the separate Clojure jars are project-specific. To create a sample project to play around in, say lein new foo someplace convenient. Then you'll need to cd foo, get your Clojure & contrib jars with lein deps (the project.clj skeleton provided by lein new already contains entries for both) and start a REPL with lein repl.
Finally, you could use the new cljr project; it has a comprehensive README which should get you started in no time, and with it you'll be able to say cljr repl to get a Clojure REPL anywhere, without the need to create a "project".
I met the same problem. jline.ConsoleRunner (at least about jline-0.9.5 which I use) seems not to be able to find class files in the path added to class search paths from -cp option of 'java' command. It means it can't find neither classes in your current directory. I solved this by copying clojure.main under /Library/Java/Extensions/ too.
I'm using emacs with clojure-swank and slime and trying to set my development environment. And I ran into a problem. When I start a repl I'm stuck in an unknown directory preventing me to load my namespace. Because the clojure repl can't find the right file.
Does anyone know how to change the current directory?
PS: I've just started using emacs and slime so I'm a noob.
If you want to change slime's notion of the current directory, press ,cd<CR> (<CR> = Enter) and type in the path.
However, this is not really the proper solution to the problem. The proper solution involves setting up the classpath so that you can (use 'your.namespace). To this end, I wonder if this very long answer I provided to a question about setting up the classpath properly might be helpful... :-)
Incidentally, I somewhat object to solutions involving add-classpath, as that is currently marked as deprecated and was never meant to be relied upon in the first place... Though on the other hand, it certainly may work perfectly well and it's worth knowing about just in case it might come in handy as a quick-and-dirty classpath injection gimmick.
Now if you want a real nice SLIME-based development environment, I'd like to point you to a very nice clojure-project elisp function by Phil Hagelberg which sets up all relevant variables and launches SLIME in the main directory of a project (to be supplied interactively). It's been posted to the Clojure group, in fact here's a link to the Mail Archive's copy of that message. Note there's one thing which needs correction in there -- swank-clojure-jar-path ought to be set to the full path to clojure.jar. Otherwise it's a fantastic tool.
Actually I mentioned that function in this response to a question about managing the classpath when using Clojure and Emacs. The other answers might be interesting as well.
And if you're only just beginning to use SLIME, do watch the SLIME video, linked to from SLIME's homepage which is now available under a link posted by Michiel in the comments. It's a very good introduction. :-)
Leiningen is a new Clojure build tool that worries about classpathing for you. You set up a simple project file in the project's root directory to specify the main class of your project, and it automagically discovers all the JARs in your lib directory and loads them for you.
I now just type "lein swank" at a command line and then M-x slime-connect in Emacs, and everything just works. (This could easily be automated with a little Elisp.)
More info in this blog post.
Short answer:
(load-file "full-path-to-definition")
Long answer:
Here's what my bootstrapping process looks like:
In ~/.clojure/user.clj (this file is auto-run when you boot slime/clojure):
(add-classpath "file://path/to/foo.jar") ; Include these jars in the classpath
(add-classpath "file://path/to/foo2.jar")
(load-file "file://workspace/bootstrap.clj")
In bootstrap.clj:
(compile 'my.package)
Package file(s) is at /workspace/my/package.clj
In package.clj:
(ns my.package)
(defn foo [] (+ 2 2))
The best approach I've found when using Emacs, SLIME and swank-clojure is to use the (Emacs Lisp) function swank-clojure-project. From its documentation:
(swank-clojure-project PATH)
Setup classpath for a clojure project and starts a new SLIME session.
Kills existing SLIME session, if any.
If you do a "M-x swank-clojure-project", it will interactively prompt you for your project directory; once you've selected it, all the jars in a lib subdirectory, as well as the src and classes folder will be added to your classpath. It will also honor a Maven/lein directory structure, in other words: it will usually just work.
If you change something, e.g. add a new jar file, simply do swank-clojure-project again.