I am totally new to lisp, but I came accross this code https://github.com/wjur/sym-diff-lisp/blob/master/sym-diff.lsp which calculates derivatives in lisp and I wanted to know how to run it. I see the examples in comments in the beginning but I am not sure how to run it.
I just installed clisp in ubuntu and tried to run 'clisp sym-diff.lsp' but I dont know where am i supposed to pass the exact functions that I want to differentiate. Should I pass it as arguments when running sym-diff.lsp?
Start CLISP - you should have a terminal window, which is waiting for you to do something. This is your REPL.
You have to load the code, thus:
(cd "file-location")
(load "filename")
Once you done that then you can type in your examples into the REPL.
Related
as the title said, I am learning common lisp right now and using portacle, following Practical Common Lisp by Peter Seibel.
I found it quite annoying that the Slime-repl-sbcl buffer keep the writing at the end of the screen (using C-l or C-v doesn't help since once I try to execute an expression it will roll back to the end of the screen)
Is there anywhere to improve this? (should I just write on a text file and compile it? the only similar subject I found was about Cider repl and couldn't understand it, since I am still new to lisp)
Thank you for your time
I would like this fixed too. No solution yet. In slime-repl.el, I found:
scroll-conservatively (variable):
A value of zero means always recenter point if it moves off screen.
my test wasn't conclusive.
slime-display-output-buffer (function), which calls slime-repl-show-maximum-output, which role is to
Put the end of the buffer at the bottom of the window.
I rewrote slime-display-output-buffer without this call, but that wasn't conclusive either.
Maybe I tested badly.
(I'm making this answer a wiki)
You would indeed typically write in a source file, and compile each expression separately. Use the REPL only to test functions or do simple computations. To compile functions (or really, any toplevel expression), use C-c C-c - bound to slime-compile-defun by default - when the point (= your cursor) is inside the function's code. The REPL will then "know" of it, so you can test it there, but as it is now written in file, you can also modify it without having to copy/paste anything ! Just make sure to recompile functions that you modify !
If you want to compile/load entire files at once, look at the other compilation commands, e.g. slime-compile-and-load-file (see the SLIME manual, and its Compilation section)
For your problem: there is Emacs variable, named comint-scroll-to-bottom-on-input (or something along those lines, can't remember exactly ...) which enables the behaviour you are seeing, so that you don't have to scroll back to enter new expressions. It is possible that SLIME has another variable which configuring this behaviour for its REPL; in that case, it would probably be named almost the same, and you can set it to nil to disable it.
Finally, don't hesitate to look at the other tools provided by SLIME ! For example, it comes with an "inspector" (see the relevant section), that you can use instead of evaluating expressions such as *db* in the REPL. In that simple case, it makes no real difference, but if you start having - say - hash-tables or different structures/classes, it becomes an incredible tool for interactive development, to examine the internal of almost everything, redefine things directly from within the inspector without needing complex accessors, and so on.
I've recently set up Portacle 1.3 for learning common lisp on Win 7. However, whenever I run my code I get the error, even if there is no code.
Running individual lines works fine, however. The error only shows when I run the whole file.
I tried putting some code in an EVAL function, but I believe that only accepts one argument at a time, so I couldn't run a whole program in it.
I've found a similar error in this stackoverflow page, but their code contains colons and that's where their error lies.
I think it might be an error in the code that runs mine, seeing as I get the error even if I compile with no code, however I know nothing.
The full error:
main.lisp:1:1:
read-error:
READ error during COMPILE-FILE:
illegal terminating character after a colon: #\
Line: 1, Column: 13, File-Position: 12
Stream: #<SB-INT:FORM-TRACKING-STREAM for "file [path to file]\\main.lisp" {1005F5F0D3}>
Compilation failed.
Portacle is a standalone Emacs packaged with everything needed for Common Lisp development and which uses SBCL as the Common Lisp implementation.
I believe what you do when you say 'compile the whole file' is call slime-compile-and-load-file which is bound to the key sequence C-c C-k by default. There are a lot of moving components here:
Emacs is the text editor here. It also takes care of launching all the necessary components for Common Lisp development.
Slime is one such component. It serves as interface between Emacs and your Common Lisp implementation (SBCL in this case, but supports any Lisp in theory). Basically it sends the code you wrote in Emacs to your Lisp for evaluation.
SBCL is the Common Lisp implementation. In this case it is a compiler. This is what evaluates the code it receives and spews out the answers to the user interface in Emacs, through Slime. It also 'lives', in the sense that you interact with it by modifying the state of the loaded Lisp image, keeping track of defined functions, global dynamic variables and much more. This is why you can have the REPL, and why you need Slime to interact with it.
So to debug your problem, I would try to:
Launch SBCL from the Windows shell and run a simple .lisp file to check that everything works. You can put for example (format t "~a" (lisp-implementation-type)) in a .lisp file and run it in SBCL from the shell by calling (load "...\\file.lisp"). It should return "SBCL".
Create a completely new file using Emacs (and not weird Windows programs that could mess up the files) (C-x C-f), and try to call the compile from there (C-c C-k).
And I believe you made the right choice of IDE. Portacle is arguably the simplest tool out there if you are a total beginner in Common Lisp and do not know Emacs configuration. The keybindings are a bit daunting though.
This question arose when I noticed, upon starting an emacs lisp script, that the command C-h f did not recognize the function org-table-get-field. That is to say when I type C-h f org-table-get-field, I get the [No Match] in the EchoArea. However when I run a lisp code block, I CAN get a match and information on org-table-get-field. Does anybody know what the machine is doing that all of a sudden it has access to function information it did not before I evaluate lisp code blocks?
The code defining a function or variable needs to have been loaded or otherwise evaluated, for the help commands to recognize it.
No doubt the code in question here is autoloaded upon your first use of some command. Once it has been loaded, C-h f works for your function, org-table-get-field. Autoloading is the magic you were wondering about.
See the Elisp manual, node Autoload.
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.
If I'm entering code into the REPL using clisp, as in the program you get when you do sudo apt-get install clisp, is there a way to take all the code you've entered so far and save it in a file? I'm a Lisp beginner so I don't know if that's a ridiculous request or not.
You can start output recording with the function DRIBBLE.
Other than that I would run CLISP from a terminal program which can save input / output.
As the minimum I would usually use Emacs, run a shell via M-x shell and start the Lisp there. That way the I/O goes into an Emacs shell buffer.
There is also SLIME, which sets up quite a bit more functionality inside Emacs to communicate with a 'slave' Common Lisp. A 'listener' (aka REPL) is part of that.
There is probably a better way, but... If you are using a decent terminal program, you should be able to select the text in the terminal and save it to file. This would include your typed input as well as output, so you would have to manually remove the output.