Now you have me thinking about how short I can make that. My revision: (defun do... | Hacker News

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SeanLuke on Feb 13, 2024 | parent | context | favorite | on: K Isn't Lisp (2004)

Now you have me thinking about how short I can make that. My revision:

    (defun doit (elts)
        (mapcar (lambda (elt) `(,(count elt elts :test 'equal :key 'second) ,elt))
        (delete-duplicates (mapcar 'second elts) :test 'equal)))))

or maybe

    (defun doit (elts)
        (loop for elt in (delete-duplicates (mapcar 'second elts) :test 'equal)
        collect `(,(count elt elts :test 'equal :key 'second) ,elt)))

tmtvl on Feb 13, 2024 [–]

As much as Lisp isn't meant for code golf, I think the loop variation could be used as a (rather long) one-liner.

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