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POCommon Lisp: defpackage and exporting symbols that are created programmaticaly
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copied!<p>how would you / should you export symbols from a package, when you have not yet created them at the time of calling the defpackage macro?</p> <pre><code>(defpackage :package-a (:use :cl) (:export :fruit-type :animal-type :orange :apple :peach :cat :dog)) (deftype fruit-type () '(member ORANGE APPLE PEACH)) (deftype animal-type () '(member CAT DOG)) (defparameter *other-symbol-names* '("A1" "A2" "B1" "B2")) ;imagine a longer list here ;with names generated by a function (defparameter *other-symbols* (mapcar #'(lambda (sym-name) (import (make-symbol sym-name)) (find-symbol sym-name)) *other-symbol-names*)) (mapcar #'export *other-symbols*) (setf A1 32 A2 33 B1 34 B2 35) </code></pre> <p>also there is another package</p> <pre><code>(defpackage :package-b (:use :cl :package-a)) (in-package :package-b) (format nil "~a ~a ~a ~a" |A1| |A2| |B1| |B2|) </code></pre> <p>I have read in "The Complete Idiot’s Guide to Common Lisp Packages" that "Now that you’ve learned all about the myriad functions and macros that can be used to manipulate packages you shouldn’t really be using any of them. Instead, all of the functionality of IMPORT, EXPORT, SHADOW, etc. is all rolled up in a single macro called DEFPACKAGE, which is what you should use for real (non- prototype) code."</p> <p>Is there a code smell in my above code? Also, how would you export the other symbols (cat dog animal-type, etc. -- there are many of them) to avoid duplication?</p>

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