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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.
My clojure repl started throwing a "Variable binding depth exceeds max-specpdl-size" error and I've gotten thrown into the debugger.
I am currently accessing slime via clojure-jack-in and I am executing a reduce on a reasonable sized dataset. A bit of googling leads me to believe that the error is because I'm generating too many temporary variables, specifically:
User Option: max-specpdl-size
This variable defines the limit on the total number of local variable bindings and unwind-protect cleanups (see Cleaning Up from Nonlocal Exits) that are allowed before Emacs signals an error (with data "Variable binding depth exceeds max-specpdl-size").
This limit, with the associated error when it is exceeded, is one way that Lisp avoids infinite recursion on an ill-defined function. max-lisp-eval-depth provides another limit on depth of nesting. See Eval.
The default value is 1000. Entry to the Lisp debugger increases the value, if there is little room left, to make sure the debugger itself has room to execute.
found here.
I have little experience with debugging clojure-swank/slime so I hope someone can help.
EDIT:
I'm using clojure-mode 1.11.4 with emacs 24 and clojure 1.3.0, I've not installed swank-clojure, I'm using the one that comes bundled with clojure-mode via clojure-jack-in as I explained earlier.
Just in case someone is looking for a possible answer to this questions....
This error, as outlined, does often mean a problem, but not always. You can legitimately exceed the default depth setting in situations where you have large data structures or where you are usiing some emacs features, such as defadvice, which can result in deep bindings etc. You can increase the depth and see if that helps (for example, double it), but in this case it probably is an error.
One of the problems with swank-clojure is that it is tightly coupled with an old version of slime. This means improvements and bug fixes in slime are not available. It is because of this tight binding that the coljure community has moved away from using slime to using cider and I'd strongly recommend switching to using cider rather than slime and swank-clojure.
Scheme newbie question-
Is there a way for me to reset my current REPL environment (i.e. the default user environment) without quitting and restarting my REPL? Basically I'd like a way to wipe out my current environment so that none of my previous defines are in effect. This is using GNU/MIT Scheme.
If this is impossible, what's the best practice here when just messing around with code in the REPL? I've heard people talk about creating and deleting packages, but most examples seem to be for Common Lisp which is a bit different.
I did find information on how to do this in the Clojure REPL but there were caveats and it seems like it's Clojure-specific: Can I clean the repl?
Thanks!
Edit: I'm able to accomplish functionally the same thing by quitting and restarting the REPL process itself. I found a way to do this but keep the connection to my editor (vim) alive using vim-screen. This is an acceptable solution if there's no way to do it from within the REPL. However, I'll keep the question open a bit longer to see if there's a way to do this inside the language as I think it will be instructive.
I think that this is implementation specific, but in MIT Scheme you can clear the REPL environment with:
1 ]=> (ge (make-top-level-environment))
The function (ge [environment]) "Changes the current REP loop environment to [environment]." and the function make-top-level-environment "returns a newly allocated top-level environment".
MIT Scheme has a bunch of environment-management functions that you can peruse here
I tested this on Mac OS X (10.6.7) with MIT Scheme 9.0.1 installed via the pre-built binary from the GNU site, with the following REPL session:
1 ]=> (define foo 1)
;Value: foo
1 ]=> foo
;Value: 1
1 ]=> (ge (make-top-level-environment))
;Value 13: #[environment 13]
1 ]=> foo
;Unbound variable: foo
;To continue, call RESTART with an option number:
; (RESTART 3) => Specify a value to use instead of foo.
; (RESTART 2) => Define foo to a given value.
; (RESTART 1) => Return to read-eval-print level 1.
2 error>
I think that different implementations have different conventions but I don't think there's anything quite like Common Lisp's packages. If you're not wedded to MIT Scheme, you should check out Racket and Dr Racket, which is a nice IDE that might be more powerful than a plain REPL at the command line, and I think it has some kind of module system. Racket is its own dialect of Scheme, so depending on what you're doing, it might not be appropriate. (the default language module in Racket is not the same as MIT Scheme)
I've struggled with all this recently (past few months) when I went looking for a Scheme that could run the code from Lisp in Small Pieces, which has a bunch of weird macros. Gambit ended up being the best bet. If you don't have a need like this though, check out Racket.
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've been wanting to teach myself Lisp for a while. However, all the interpreters of which I've heard involve some flavor of emacs.
Are there any command line interpreters, such that I could type this into the command line:
lispinterpret sourcefile.lisp
just like I can run perl or python.
While I'd also like to become more familiar with Emacs (if only not to be frustrated when I work with somebody who uses Emacs), I'd rather decouple learning Emacs from learning Lisp.
Edit: I actually want to follow SICP which uses Scheme, so an answer about Scheme would be more useful. I'm just not that familiar with the differences.
You could also try DrScheme, which whilst not exactly a standalone interpreter, isn't emacs :)
It's basically a simple IDE that has an area to type in code that can be executed as a file, and then another area that is the running interpreter that you can interact with.
(Also, find the UC Berkeley CS61A podcasts and listen to them, as well as reading SICP)
It looks like Steel Bank Common Lisp (SBCL) also caters to what you want:
http://www.sbcl.org/manual/#Shebang-Scripts
SBCL is both top rate and open source.
Checkout CLISP wiki-link that ie. was used by Paul Graham
Direct link
I often write lisp shell scripts which start with this line:
#!/usr/bin/clisp
Then you don't even need to type "lispinterpret" on the command-line. Just mark the script executable and run it directly.
Most scheme interpreters that I am familiar with can be run from the command line. (Much of the list below is extracted from the comparative table at Alexey Radul's Scheme Implementation Choices page. There is a more extensive list at schemewiki but that page does not immediately provide command-line invocation syntax.)
Here's how you run a number of implementations at the command line:
Chez Scheme: scheme, petite
MIT Scheme: mit-scheme
Scheme 48: scheme48
RScheme: rs
Racket: racket (But I recommend trying the DrRacket IDE, especially for beginners.)
Guile: guile
Bigloo: bigloo
Chicken: csi
Gambit: gsi
Gauche: gosh
IronScheme: IronScheme.Console
Kawa: kawa, java kawa.repl
Larceny: larceny
SCM: scm
If you are looking for Scheme to work with the SICP, take a look at MIT/GNU Scheme
http://groups.csail.mit.edu/mac/projects/scheme/
http://www.gnu.org/software/mit-scheme/index.html
The most widely used IDE for Common Lisp, particularly in the free software subset of the community, is in fact SLIME, which runs on Emacs. You can use whatever CL compiler you prefer and invoke Lisp source files the way you describe, but if you do that, you won't be taking advantage of many of Lisps dynamic features that are so incredibly useful while developing your application.
I suggest you take a look at this SLIME demonstration video to see what I mean, even though it might be a bit outdated at this point.
If the problem is that you (think you) don't like Emacs, I seriously suggest you try to learn it. Seriously. No, really, I mean that. However, there are alternatives, such as the IDEs provided by commercial Lisp implementations such as Allegro and Lispworks (free trials available), or an Eclipse plug-in called Cusp.
Did you try Allegro CL from http://www.franz.com/?
#Nathan: I've upmodded the Common Lisp links, because you asked about Lisp (especially with reference to Emacs Lisp). However, Common Lisp is very different from Scheme. A program written for one is unlikely to run on the other.
As you mentioned, SICP is for learning Scheme, not Lisp (or at least, not Common Lisp and not Emacs Lisp). There are some overlap in principles, however you can't simply cut and paste code from SICP and expect it to run on any Common Lisp or Emacs Lisp system. :-)
No "interpreter" requires emacs.
Also, emacs can run elisp in a headless manner.
It seems like scheme shell is suitable for your purpose.
Take a look at http://www.scsh.net/index.html
Another good dialect of lisp is cmucl. They used to love to brag about being the "fastest" lisp.