Data commit

Task/Naming-conventions/Common-Lisp/naming-conventions-1.lisp

@@ -0,0 +1,34 @@
+(defvar *language* :en
+  "The language to use for messages (defaults to English)")
+
+(defmacro with-language ((language) &body body)
+  "Locally binds *LANGUAGE* to LANGUAGE"
+  `(let ((*language* ,language))
+     ,@body))
+
+(defgeneric complain% (language about)
+  ;; The % indicates this is an “internal” implementation detail.
+  (:method ((language (eql :en)) (about (eql :weather)))
+     "It's too cold in winter"))
+
+(defun complain (about)
+  "Complain about something indicated by ABOUT"
+  (princ (complain% *language* about) *error-output*)
+  (terpri *error-output*)
+  (finish-output *error-output*)
+  nil)
+
+(defmethod complain% ((language (eql :es)) (about (eql :weather)))
+  "Hace demasiado frío en invierno")
+
+
+(complain :weather)
+(with-language (:es)
+  (complain :weather))
+(complain :weather)
+
+⇓
+
+It's too cold in winter
+Hace demasiado frío en invierno
+It's too cold in winter

Task/Naming-conventions/Common-Lisp/naming-conventions-2.lisp

@@ -0,0 +1,7 @@
+(defun do-something (argument &key ((secret-arg secret) "default"))
+   (format t "Argument is ~a, secret is ~a" argument secret))
+
+;; Normal caller
+(do-something "Foo")
+;; Special caller:
+(do-something "Foo" 'secret-arg "Bar")

Task/Naming-conventions/Common-Lisp/naming-conventions-3.lisp

@@ -0,0 +1,9 @@
+#+sbcl
+(defun user-name+home-phone (user-id)
+  "Returns the “real name” and “home phone” for user with ID USER-ID as multiple values.
+Reads the GECOS field. SBCL+Linux-specific, probably."
+  (destructuring-bind (real-name office office-phone home-phone &rest _)
+       (uiop:split-string (sb-posix:passwd-gecos (sb-posix:getpwuid user-id))
+                          :separator ",")
+     (declare (ignore office office-phone _))
+     (values real-name home-phone)))