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(vector-push 'a' str) is the same as (vector-push 'a 'str) is the same as (vector-push (quote a) (quote str)) -- you're trying to push the symbol A onto the symbol STR.

You probably want VECTOR-PUSH-EXTEND, too.

I found the following example of a strange behaviour of command EVAL inside LET constructions. Executing the code (setf z 666) (let ((z 14)) (print z) (eval '(setf www z)) ) results in printing the value 14 of the variable z inside LET construction, but the variable www takes the value 666, not 14!...

stackman wrote: Why do some people prefix the loop keywords with a colon?

They have a really bad sense of aesthetics

it's a draft, thus it can be improved probably (especially the (= 1 (length lst)) part). It has O(log N). FWIW, for (= 1 (length list)) do (null (cdr list)) -- or reverse that and the T clause and drop the NULL. Does this thing have to be nondestructive? I want to write something like (defun insert...

stackman wrote:Hi,
Is there a simple way to return the fractional part of a number in common lisp?
At the moment I am using

Code: Select all

(multiple-value-call (lambda (x y)(declare (ignore x)) y) (floor 1.5))

but this seems a bit verbose.

FWIW, (nth-value 1 (floor 1.5))

Thanks for your detailed answer! Your last remark about "code walker" is most helpful, I shall look at it. As far as I understand your answer, there is no inbuilt standard "code walker" in LISP? It doesn't matter; you can't tell if two functions do the same thing anyway. You can...

(if (listp x) t) doesn't terminate the loop; it just keeps looping, and eventually returns nil. Use (return t)

Probably the reason it "doesn't work" is that the output stream doesn't get flushed: "Your name Thomas" is written to the output, but doesn't appear on your screen until much later (or possibly never, if you're doing something weird like running your function and immediately shut...

Your structure uses too many conses. Use (parent left . right) [i.e., (parent . (left . right)) ] rather than (parent (left) (right)) [i.e., (parent . ((left . nil) . ((right . nil)))) ], then you can tell whether, say, "left", is a question or an answer using CONSP. Your original tree loo...

You have several problems there. There are misplaced parentheses, FIT is a list, not a number, and CONS only allocates a new cons cell (you use it as if it modifies TOP; you never use the value, so it just gets thrown away). Try (defun fitrange (list) (loop for fit in list if (<= 1 fit 10) collect f...