I often find my self starting some long running process from the REPL and then wish I could carry on using the REPL for other tasks while it was running. Can I use slime to background the current thread or start a new REPL control thread? Starting an additional REPL buffer would be fine as well.
Edit:
Hm, I somehow managed to miss the Clojure tag on your question. I would be very suprised if the solution below worked for Clojure, since, as you probably know, the Clojure community unfortunately (at least for those of us using Clojure and CL) maintains its own version of Slime. I won't delete the answer, because it might be helpful for CL programmers searching for this functionality.
Unless there is a similar solution for Clojure, which allows multiple REPLs multiplexed over a single socket, you could maybe just start a second Swank server by hand (from the *inferior-lisp* buffer) and connect to it via slime-connect as a workaround. (Can't test this ATM, since I stopped using Slime with Clojure a while ago.)
Did you try the slime-mrepl contrib? I have not actually used it myself, but a quick test worked for me under CCL/Win/Emacs 24.
I tested it like this: M-x slime, enter (sleep 10) in the REPL, switch buffer, M-x slime-new-mrepl.
Please forgive me for a somewhat trite and non-slime specific answer; on the upside it will work with any clojure REPL.
When I know in advance I am starting a long running task from the REPL then I start the computation using future and check with future-done? before deref-ing it.
This might not answer your question, but it might be helpful to realize that as long as (slime-communication-style) is :spawn, evaluations done using C-x C-e always spawn their own thread and can run in parallel to whatever is happening in the REPL thread. Output (from println etc.) will appear in the REPL buffer.
Related
I don't get any GC logging messages when running Racket code in raket-mode in emacs.
Running the following code in DrRacket gives back a log entry while running it in Emacs REPL does not.
(define my-logger (make-log-receiver (current-logger) 'debug 'GC))
(collect-garbage)
(sync/timeout 1 my-logger)
How can I get the log messages in the Emacs REPL case?
Make sure you have a somewhat recent version of racket-mode (e.g. latest from MELPA).
Use C-c C-l a.k.a. M-x racket-logger to open a racket-logger-mode buffer.
If you have any problems or questions, feel free to open an issue.
Update: The above instructions don't really answer why your own program isn't getting a log event. This is a really interesting bug -- thanks! More conversation on the issue thread. When I figure it out, I'll try to come back here and update this answer again with something hopefully interesting and educational about Racket logging.
Update: This turned out to be a "what was I thinking?" bug in racket-mode. I was creating a new logger:
(define global-logger (make-logger))
(current-logger global-logger)
rather than just using the existing one:
(define global-logger (current-logger))
The existing logger is special, as the Racket documentation for loggers explains:
On start-up, Racket creates an initial logger that is used to record events from the core run-time system. For example, an 'debug event is reported for each garbage collection (see Garbage Collection).
I've pushed a commit to a topic branch and when I get all-green from CI I'll merge to master; it should be available via MELPA soon after.
I constantly find myself doing multiple manual (require '[my.lib :as foo]) right after I start cider with M-x cider-jack-in in my clojure projects. I suspect there must be a hook to run some code on a successful connection. Is there? The alternative would be to put all requires in an external file and just (use 'that.namespace) but lazy as I am, I want to even skip that step if possible.
UPDATE:
Putting the forms in .lein/profiles.clj :injections is fine as long as one uses them exclusively in the Repl (as per lein repl). To make them available from the nrepl in emacs one must use the second solution named by arrdem below.
Here is some more comprehensive info.
Leiningen's :injections feature is the cannonical way to pull this one off. Once Lein boots a Clojure instance, the code in :injections gets evaluated allowing you as you say to populate the user namespace with libraries that you use all the time.
Another approach is to (ab)use the file user.clj by adding a :dev profile with a dev-only source path that "happens" to contain a user.clj with preloading code in it. This is done in Grimoire with the file dev/user.clj which serves to create some utility functions in the REPL.
I am using LispBox on MacOSX.
My question is, how can I break a loop in this environment?
for example. I typed:
CL-USER> (loop)
then, it is in a loop, I don't know how to break it.
Thanks!
Try C-c C-c (slime-interrupt).
Have you tried the Mac version of ctrl-c (I believe it's command-c)? Sending an interrupt signal works for many lisp systems. SBCL will, for example, let you choose among several restarts. I don't know how Clozure (the compiler that comes with lispbox) will handle it.
I'm an experienced C++/.NET/Java Windows/web programmer trying to learn (Common) Lisp. I'm reading Practical Common Lisp and using SLIME.
I'm getting the Lisp language easily enough, but I'm having trouble groking the mechanics of development. One of my issues is dealing with Emacs. I have no experience with it and find it generally confusing with hard to find/figure out commands.
Specific questions:
I get the REPL, but I don't quite get how I can use it effectively. When I need to change a function I have to retype the defun and make changes (tedious and error prone). How can I do this better?
How do I get from entering code at the REPL to actually having a program? I'm used to the C model where you have code files that you can review, edit and recompile. I know Lisp has something similar (via the load function), but how does one get a function I just defined and tested into a file to be saved? I'm hoping there's a better method than my current select+copy+paste.
How do you debug errors? Is there any ability to step into code like I would with other languages?
As long as the S-expression is valid, I don't get any errors when entering a (defun ...). It's not until I try to use it that I find out it's not valid. Is there any way to get errors sooner (i.e. compile the code)?
Is there some IDE that would be more familiar to me or allow me to play with the language easier?
Should I switch to learning Scheme instead?
Any tips would be greatly appreciated!
-I get the REPL, but don't quite get how I can use it effectively. When I
need to change a function I have to
retype the defun and make changes
(tedious and error prone). How can I
do this better?
-How do I get from entering code at the REPL to actually having a program?
I'm used to the C model where you have
code files that you can review, edit
and recompile. I know lisp has
something similar (via the load
function), but how does one get a
function I just defined and tested
into a file to be saved? I'm hoping
there's a better method than my
current select+copy+paste.
Load SLIME. Enter code in your .lisp file, and then run slime-eval-buffer to load all your code into Lisp. Then, for a specific function you are hacking on C-e, C-j to redefine it in your running Lisp.
-How do you debug errors? Is there any ability to step into code like I would with other languages?
Yes. (trace 'my-function) - or some variant on that - and when my-function is called, it will break into the debugger.
-As long as the S-expression is valid, I don't get any errors when entering a
(defun ...). It's not until I try to
use it that I find out it's not valid.
Is there any way to get errors sooner
(i.e. compile the code)?
To some degree, that is a characteristic of dynamic languages (Python, Perl, Ruby, Lisp, etc.). Try SBCL for better error-checking.
-Is there some IDE that would be more familiar to me or allow me to play with the language easier?
Emacs is the free IDE for Lisp. Allegro has a free edition I believe; I've never tried it though..
-Should I switch to learning Scheme instead?
Nah, Scheme is not as pragmatic a language.
I'm an experienced C++/.NET/Java Windows/Web programmer trying to learn (Common) Lisp. I'm reading Practical Common Lisp and using SLIME.
One can also use the LispWorks Personal Edition for learning Lisp. It has some limitations and the full product is commercial, but it is quite a bit easier to use.
I get the REPL, but don't quite get how I can use it effectively. When I need to change a function I have to retype the defun and make changes (tedious and error prone). How can I do this better?
The REPL has a history. With keyboard commands you can get back prior input and change it. Other than that just edit a Lisp file and compile code from there. In Lisp you can compile/eval individual expressions and definitions. Typical IDEs like SLIME, LispWorks or Allegro CL allow you to run code also from normal Lisp text windows - additionally to executing expressions in the REPLA (aka Listener).
How do I get from entering code at the REPL to actually having a program? I'm used to the C model where you have code files that you can review, edit and recompile. I know Lisp has something similar (via the load function), but how does one get a function I just defined and tested into a file to be saved? I'm hoping there's a better method than my current select+copy+paste.
Copy and paste in one thing. But the correct way is to work from a text file in an editor window. One can compile/load expressions, the editor buffer or the associated file.
How do you debug errors? Is there any ability to step into code like I would with other languages?
See STEP, TRACE and related. SLIME, LispWorks and Allegro CL have lots of additional features.
As long as the S-expression is valid, I don't get any errors when entering a (defun ...). It's not until I try to use it that I find out it's not valid. Is there any way to get errors sooner (i.e. compile the code)?
For many cases one uses a compiler. The compiler will find a range of errors and also will note when something is unusual (for example a function does not exist or a variable has not been defined).
-Is there some IDE that would be more familiar to me or allow me to play with the language easier?
LispWorks, Allegro CL are the best under Windows. There are some alternatives like Corman Lisp (I don't know it is maintained right now) or even Ufasoft Lisp.
Should I switch to learning Scheme instead?
Not really.
It doesn't sound like you're really using SLIME, or at least not in the way it was intended to be used. ("have to retype the defun", "the C model where you have code files")
I recommend watching some SLIME screencasts (or, even better, watching a Lisp programmer use SLIME for a few minutes, if you have one handy). The SLIME webpage has a couple.
It sounds like you'd really enjoy the DrRacket IDE. Racket is closer to Scheme than to Common Lisp, but you could dip your toes into the Lisp family without the speed bump of the Emacs style of development.
I'm currently in the process of adding functionality to an existing J2EE webapp, in a Tomcat container, and I'm writing my additions using Clojure. My setup is simple: I just add calls to static methods generated by clojure, and code all the hard work from the clojure side. The build process consists in compiling clojure code (lein uberjar) and then compiling the java code with that jar on the classpath.
In the webapp init, I have a call to a generated class that fires up a swank server with a (swank/start-repl). I'd like to be able to connect my Aquamacs' slime to that server, and work interactively from there (up to a point, I won't try nothing that requires a java-side recompilation). But I have a situation that I don't quite understand. If I do a \M-x slime-connect, I get a REPL prompt (after being notified that there's no inferior lisp process, which I think it's ok, since the inferior lisp process is running outside emacs control). I can evaluate forms perfectly, and I can even inspect things like my.own.namespace/my-var. However, if I visit a file with an already compiled clojure code, I can't seem to make slime recognize it as its source. Consider a simple clojure file:
(ns my.namespace
(:gen-class
:name my.namespace
:methods [#^{:static true} [testFunc [] void]]))
(def *secret* "shhhh")
(defn -testFunc []
(println (str "our secret is: " secret)))
Assuming that this was compiled and included in the uberjar loaded by the webapp, I can eval/inspect my.namespace/*secret*. But If I try to eval inside the code buffer, Slime thinks I'm on the user namespace (which can even make sense!). But now I'm left with a single working option - I have to evaluate - one by one, all the forms in the file! \C-c \C-l (loading the source file) won't do nothing - apparently just returns nil and outputs nothing else. Compiling everything seems to do just that - it compiles, shows errors if it finds them, but won't change my namespace. And the strangest is the \C-~ (sync package and directory), which using Common Lisp it does just what I want, but here it freezes the clojure REPL for good.
There's always the option of switching to the REPL, typing (in-ns 'my.namespace), and then all works properly. But that simply isn't practical enough when the clojure files are growing in number (as the namespace of the code buffer won't change automatically!)
My question is, then, whether I'm lacking a basic command/configuration - or if there's an obvious reason for this behavior to happen as such.
I may be misunderstanding your problem, but can't you (while visiting this hypothetical buffer in emacs), hit C-c C-k to compile the buffer in your current Clojure instance (what Slime is connected to)?
Then, in the Slime buffer, switch to this namespace with a (in-ns 'my.namespace). Then you should have access to what you compiled in that namespace.
Switching namespaces automatically on compile has never been the default for swank-clojure, though it might be an optional slime feature that happened to work with Clojure. But C-c M-p to switch the repl to the current buffer's namespace has always worked for me, and I've never heard of anyone having trouble with it.
Are you running on the latest stable versions of clojure-mode and slime-repl? Do you have swank-clojure.el installed? (You shouldn't need it.) It sounds like this could be due to mismatched versions of the elisp libs. If that's not the problem it could be an Aquamacs bug; swank-clojure is designed to work with GNU Emacs. It could also be a bug in slime if you are running from trunk rather than the latest elpa release.
I've just found out that removing the culprit for this issue: slime-redirect-inferior-output, from slime-repl.el, was being called from a hook I had setup. It turns out that it doesn't play well without an inferior-lisp-process (read, a swank server started from within emacs).
So a quick workaround hack is just to remove the error form from that function, like this. Now the hook proceeds, and the namespaces are automatically calculated. As intended. Thank you for the suggestions, nevertheless - they led me to this solution!