Land of Lisp is an educational comic that teaches readers how to program in Common Lisp.
Questions tagged [land-of-lisp]
30 questions
3
votes
1 answer
Can you program without REPL on Lisp?
So I just got Land of Lisp and started to do the first program.
I have a couple questions.
Is there a way to just write some code and run it through a compiler, or interpreter, and not use the REPL thing? I don't like it much. I can't seem to go…
Qwe Asd
- 49
- 2
2
votes
1 answer
Breaking a function into multiple lines
Here are some source code for an example from the amazing book "Land of Lisp" :
(defun random-node ()
(1+ (random *node-num*)))
(defun edge-pair (a b)
(unless (eql a b)
(list (cons a b) (cons b a))))
(defun make-edge-list ()
(apply…
Chiron
- 20,081
- 17
- 81
- 133
2
votes
1 answer
Wumpus game's make-city-edges function causes heap overflow
Going through the Land of Lisp book, I managed to get to the Grand Theft Wumpus game, that has me define a make-city-edges function. When I try to run it however, SBCL hangs for a while before giving me a very nasty error saying
Heap exhausted…
Electric Coffee
- 11,733
- 9
- 70
- 131
2
votes
4 answers
Understanding data mode in Lisp, why are these expressions not the same?
Currently I am reading "Land of Lisp". In one of the recent code samples the author gave:
> (eq 'fooo 'FoOo)
T
to prove that the symbols are case-insensitive. A few pages later data mode is formally introduced.
However I fail to really understand…
0xC0000022L
- 20,597
- 9
- 86
- 152
2
votes
1 answer
Printing to screen while in loop
I have this:
(loop for i below x
do (update-world)
if (zerop (mod i 1000))
do (princ #\.))
It is working, except that all the princ invokations arrive at once, at the end. The idea here is that they are a…
johnbakers
- 24,158
- 24
- 130
- 258
2
votes
1 answer
Land of Lisp function uedges->dot error or can't understand
http://landoflisp.com/graph-util.lisp
(defun uedges->dot (edges);draw undirected graphs
(maplist (lambda (lst)
(mapc (lambda (edge)
(unless (assoc (car edge) (cdr lst))
(fresh-line)
…
lin yuansen
- 1
- 5
1
vote
1 answer
Question about lisp Lambda functions from an example in Land of Lisp
I'm not quite understanding lambda functions. Here is an example function from the book Land of Lisp:
(defun edges->dot (edges)
(mapc (lambda (node)
(mapc (lambda (edge)
(fresh-line)
(princ (dot-name…
MikeJerome
- 660
- 6
- 20
1
vote
1 answer
Getting ERR_INVALID_HTTP_RESPONSE using web server code in Land of Lisp with clisp on OS X
I'm reading Land of Lisp (it's 10 years old, but so is clisp, so it seems up to date enough). I'm on Chapter 13, where you write a web server. It just opens the client socket as standard-output, then uses princ and format t to write out to the…
Lewis Cawthorne
- 55
- 6
1
vote
1 answer
land of lisp src webserver.lisp
while I was learning in "land of lisp" chapter 12 and 13 about "socket".
I use lispbox, so I need install a socket.At last, I found usocket available.
this is a sample about how to use usocket, to bulid a webserver.
(defun serve (request-handler)
…
lin yuansen
- 1
- 5
1
vote
5 answers
tweak-text: Lisp nesting exceeds `max-lisp-eval-depth
The program should reformat the string like below.
Example: (game-print '(THIS IS A SENTENCE。 WHAT ABOUT THIS？ PROBABLY.))
This is a sentence. What about ths? Probably.
But something is wrong( Lisp nesting exceeds `max-lisp-eval-depth) and i don't…
louxiu
- 2,830
- 3
- 28
- 42
0
votes
1 answer
What is syntax expression?
I read in the book "Land of Lisp", the author mentions syntax expression. Does that mean the ability to express syntax as a form of data? Is this the same as S-expression (symbolic expression)?
Amumu
- 17,924
- 31
- 84
- 131
0
votes
2 answers
LISP: Reversing a List in LISP using RPLACA/RPLACD/NCONC
So I'm trying to make a function takes in a list and reverses in place it but I'm not sure how I would use the RPLACA/RPLACD/NONC. Basically does the same thing as reverse but it uses the cons nodes of the original list and does not allocate any…
John
- 1
- 1
0
votes
1 answer
Extracting nodes form dotted list (edges) in CLISP
I'm a "Nil" or () in Lisp World.
I wanted to get a list of all nodes in edge list and I wrote a code to solve this problem. But I met some unexpected problem.
(Codes from 'Land of Lisp' - chapter 8)
;; Creating edge list
(defun random-node ()
…
Larynx
- 398
- 1
- 12
0
votes
2 answers
Cadr of a list involving assoc function
I have looked around on the net and cant find an answer to my query.
I would really appreciate if someone could provide a good answer without down rating this post.
In Lisp car, cdr are used on data mode like '(whatever here) which makes sense to…
user3619045
- 5
- 1
-1
votes
2 answers
confusion with Lisp "if" and 'cons' command
I am reading Land of Lisp by Conrad Barski and I am a bit confused on the use of the 'if' command (to name a few)..
So, I understand that writing if '() means that the list is empty and condition is false and if '(1) means the list is non empty and…
user3619045
- 5
- 1