Questions tagged [lisp]
Questions relating to editing code in Lisp-like languages (i.e., Common Lisp, Scheme and similar), and working with Lisp read-eval-print loops. Questions about specific languages should use the tag for that language (e.g., [common-lisp], [guile]). Note that Emacs's Lisp dialect is Emacs Lisp, with the tag [elisp]. Note: questions about editing Lisp in Emacs are on-topic, but general LIsp programming questions are not.
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How to properly use emacs and slime to program in Common Lisp
I'm brand-spanking new to LISP. I'm trying to get started with it, and I installed Steel Bank Common Lisp as well as SLIME so I can program in emacs. As far as I know, Slime simply provides an ...
- 105
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3
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Is there a code example demonstrating a meaningful usage of the built-in function `funcall`?
In order to understand what the symbol funcall means I have checked out its documentation. If I understand it right after reading the docs this symbol represents a function which in my eyes can be ...
- 76.3k
1
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1
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211
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Validating Arguments to a Function
I would like to validate the argument to a function before its action is executed. The main concern is the passing of a void variable. How can I trap this?
(defun is-it-bound(item)
(if (boundp 'item)...
- 76.3k
1
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0
answers
107
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What's the value in using a REPL for ELISP development? [closed]
What's the value in using a REPL? I've always wondered the advantages/disadvantages of using a REPL are (if there are any) as opposed to eval-print-last-sexp and then undoing the text printed (or ...
- 550
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Confused by what Paul Graham says about locality in his book "On Lisp" [closed]
https://sep.yimg.com/ty/cdn/paulgraham/onlisp.pdf On page 36 Paul writes the following:
The conditions above do not guarantee the perfect locality you get
with purely functional code, though they do ...
- 49.7k
29
votes
3
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When/why should I use progn?
I have seen progn being used quite a lot as I browse the configuration files of experienced Emacs users. I found this nice explanation of progn, but what I am really curious about is, what is the ...
- 47
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0
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145
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SLIME not starting properly on MacOS Emacs
Pretty new to Emacs && Lisp, trying to get started....
I'm trying to get SBCL working via SLIME in Emacs 27.1 (9.0). After following the instructions to add the MELPA repo to my .emacs and ...
- 11
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0
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47
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Autodocument function for C Code
Suppose i have this line of code presenting a C function prototype:
int sum_Func(int a, int *b)
I want an Emacs lisp function that adds the function description (initialization) according to its ...
- 2,594
2
votes
1
answer
427
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Adjusting indenting for lisp if statements
I am learning common lisp and am trying to follow the style guide suggested by lisp-lang.org. In this style guide is an if statement style that I think makes the code more readable:
(if (cond)
(...
- 5,958
1
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1
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443
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Find out, which mode is in use
Suppose I want to code something like this
case mode in
lisp-mode)
do-something
;;
shell-mode)
do-other
;;
latex-mode)
do-different
;;
esac
What ...
- 2,290
6
votes
1
answer
223
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Shortening trees list with (setcdr (nthcdr 2 trees) nil)
I am starting to learn elisp and working through this tutorial https://www.gnu.org/software/emacs/manual/html_node/eintr/kill_002dnew-function.html
and I do not understand this basic example:
(setq ...
- 76.3k
2
votes
1
answer
653
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how to specify an Cyclic list in lisp?
How to specify a list, which's last element is referring to the first element?
By specify I mean, for example, how to write a setq statement with this list.
I have seen this in the documentation, ...
- 4,501
1
vote
1
answer
438
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How to pop an arbitrary element from a list?
Q: how do I pop an arbitrary element from a list?
Given the list '(a b c d e), pop returns a and destructively
modifies the list to '(b c d e). How can I generalize this
function so I could pop an ...
- 76.3k