Lisp beginner. I am trying to add an element to a list inside a function. (defun add-element (e lst) (setf lst (cons e lst))) I cannot use the return of the function to change the original list but ...

I just started playing around with Common Lisp and tried the first euler problem which states to sum all the divisors of 3 OR 5 under some given parameter x. I would like to use a recursive solution ...

I tried to debug the function below (find-3rd-largest), and wanted to execute expressions step by step from (break), as I did for other programming languages. So, I compiled the function with C-u C-c ...

In a package I am developing I often get lists of lists. The single lists are very long and I would like to write them on a file controlling the output length as in the example. If I simply use (write ...

I am trying to understand why when I declare types, things seem to go very wrong in SBCL. Here's a little file I created to reproduce the problem: (defpackage p1 (:use :cl) (:export #:do-it #:keytype))...

About three years ago I tried to follow the GTK3 tutorial for Common Lisp. I had different problems then, but many of the examples worked without any complains. Now I took the time to reconsider it, ...

When I compile (with (speed 3)) the following (example) code with SBCL Common Lisp, the compiler issues this warning in relation with function triple returning a double-float: "doing float to ...

The sortf function from Chapter 12 of the book "On Lisp" originally used get-setf-method, which is currently unavailable in a recent SBCL by default. Therefore, get-setf-expansion was used ...

I need to process 100 Gigabytes of logs in a weird format, then do some analysis on the results. Initial parts of parsing and CLI done, tried on some test data with 1 GB and it took around a minute. I ...

I'm experiencing a significant performance difference where OpenBLAS matrix multiplication runs 2x slower when called through Lisp CFFI compared to direct C calls, despite using the exact same ...

Context In Common Lisp, symbols are how names are bound to functions and variables and macros and a bunch of other stuff. I've been working with Parenscript, which is a DSL that compiles to Javascript....

While working on the REPL I didn't encounter this error, but when building my program or running it from sources I did: SWANK::*READTABLE-ALIST* is unbound

I'm trying to discern how much performance gains I would achieve by converting Lisp (SBCL) code to assembly language. The time function on SBCL keeps giving counterintuitive results even for trivial ...

I'm trying to revive Hemlock, which now appears abandoned (original author has been absent for some time now). Mostly this has been a straightforward process of clearing out the bit rot, but I'm now ...

I am using a Windows 11 computer, running Steel Bank Common Lisp (version 2.0.0) in PowerShell by inputting functions directly into the SBCL.exe REPL to see if they work. In the process, I have hit ...