Common Lisp Ecosystem

(defmethod greet ((p person)) (format t "Hello, a!%" (person-name p))) Do you need polymorphic behavior based on multiple types? Use defgeneric and defmethod for multiple dispatch Use regular functions for single implementation

(defmethod greet :around ((p person)) (format t "[Start]%") (call-next-method) (format t "[End]%"))

;; In my-project/main.lisp: (defpackage #:my-project/main (:use #:cl) (:import-from #:my-project/utils #:helper)) Do you want automatic dependency inference from package definitions? Use package-inferred-system for modern projects Use traditional defsystem with explicit component dependencies

(sb-ext:save-lisp-and-die "my-app" :toplevel #'main :executable t :compression t)

(let ((thread (sb-thread:make-thread (lambda () (setf result (heavy-computation))) :name "worker"))) (sb-thread:join-thread thread))

;; Mutex (defvar lock (sb-thread:make-mutex)) (sb-thread:with-mutex (lock) (critical-section))

(strlen "hello") ; => 5

;; Execute external programs (sb-ext:run-program "/bin/ls" '("-l"))

;; Trigger garbage collection (sb-ext:gc)

;; POSIX interface: sb-posix ;; Network sockets: sb-bsd-sockets

(declare safe-div (Integer -> Integer -> (Maybe Integer))) (define (safe-div x y) (if (== y 0) None (Some (/ x y)))))

(define-instance (Printable Integer) (define (print-it x) (into x))))