The lisp code has a few problems. It's using a regex library that's only available in clisp (I think), it's not using the standard input like the other examples

The lisp code has a few problems. It's using a regex library that's only available in clisp (I think), it's not using the standard input like the other examples, and having two functions named has-suffix and has_suffix is no good. Also, it'll return an error if the string is shorter than the suffix. In the following example I'm using the portable http://www.cliki.net/SPLIT-SEQUENCE http://www.cliki.net/SPLIT-SEQUENCE to split the words: (defun endswith (string suffix) (let ((size (- (length string) (length suffix)))) (unless (minusp size) (equalp (subseq string size) suffix)))) (loop for line = (read-line *standard-input* nil) while line do (loop for word in (split-sequence #\Space line) do (if (endswith word "ing") (write-line word)))) It's still wordier than python, though.