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POUsing a defstruct database with remove-if-not
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copied!<p>I'm trying to adapt this <a href="http://mypage.iu.edu/~colallen/lp/node56.html" rel="nofollow noreferrer">defstruct</a> example by adding the <strong>select-</strong> functions described in the book: <a href="http://www.gigamonkeys.com/book/practical-a-simple-database.html" rel="nofollow noreferrer">Practical Common Lisp</a>. I'm running the code in Emacs using the Common Lisp package. The <strong>select-by-first</strong> does not return anything. In the Lisp book, the author does not use defstruct so I must need to do something slightly different?</p> <pre> (defun <strong>select-by-first</strong> (first-name) (remove-if-not #'(lambda (employee) (equal (getf employee :first-name) first-name)) *emp-db*)) (select-by-first "steve") </pre> <p>The complete program:</p> <pre><code>(require 'cl) ;; http://mypage.iu.edu/~colallen/lp/node56.html ;; http://www.gigamonkeys.com/book/practical-a-simple-database.html ;; (defvar *emp-db* nil) (defun add-record (emp) (push emp *emp-db*)) (defstruct employee age first-name last-name sex children)</code> </pre> <pre> <code>(add-record (make-employee)) (add-record (make-employee :age 34 :last-name 'farquharson :first-name 'alice :sex 'female)) (add-record (make-employee :age 43 :last-name 'jobs :first-name 'steve :sex 'male)) (add-record (make-employee :age 53 :last-name 'ballmer :first-name 'steve :sex 'male))</code> </pre> <pre> <code>(defun select-by-first (first-name) (remove-if-not #'(lambda (employee) (equal (getf employee :first-name) first-name)) *emp-db*)) (select-by-first "steve")</code> </pre>

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