Emacs의 리스피 모드: 복잡한 실제 예제!

It took me years to find a real-world use case for lispy-mode’s convolute key, bound to C! Here it is 🙂

My original code. There’s a loop and error handling inside. I want to move the error handling before the loop.

;; ORIGINAL
(defun post-products (products &rest keys)
  "Call the API, at most 500 products by POST."
  (let ((batches (batches products 500)))
    (loop for batch in batches
          for i = 1 then (incf i)
          with nb-batches = (length batches)
          do
             (format t "POST request ~a/~a… " i nb-batches)
             (handler-case
                 (prog1
                     (apply #'post/public/offers/v1/products/ean :verbose t :location (location) :products batch keys)
                   (format t "~&POST batch products ~a/~a done.~&" i nb-batches))
               ;; TODO: stop loop earlier.
               (error (c)
                 (format *error-output* "~&POST products error: ~a~&" c))))))

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Put the cursor here on the prog1:

(defun post-products (products &rest keys)
  "Call the API, at most 500 products by POST."
  (let ((batches (batches products 500)))
    (loop for batch in batches
          for i = 1 then (incf i)
          with nb-batches = (length batches)
          do
             (format t "POST request ~a/~a… " i nb-batches)
             (handler-case
 cursor ------> |(prog1
                     (apply #'post/public/offers/v1/products/ean :verbose t :location (location) :products batch keys)
                   (format t "~&POST batch products ~a/~a done.~&" i nb-batches))
               ;; TODO: stop loop earlier.
               (error (c)
                 (format *error-output* "~&POST products error: ~a~&" c))))))

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If you didn’t, either activate Alt-x lispy-mode and press capital C or call Alt-x lispy-convolute (with the mode active or inactive), and TADA!

;; We want to move the HANDLER-CASE before the loop.
;;
;; With lispy-mode => C (convolute)
;;
(defun post-products (products &rest keys)
  "Call the API, at most 500 products by POST."
  (let ((batches (batches products 500)))
    (handler-case
        (loop for batch in batches
              for i = 1 then (incf i)
              with nb-batches = (length batches)
              do
                 (format t "POST request ~a/~a… " i nb-batches)
                 (prog1
                     (apply #'post/public/offers/v1/products/ean :verbose t :location (location) :products batch keys)
                   (format t "~&POST batch products ~a/~a done.~&" i nb-batches)))
      ;; TODO: stop loop earlier.
      (error (c)
        (format *error-output* "~&POST products error: ~a~&" c)))))

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If I record a video, will you make it a trending one?