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jwiegley / use-package

A use-package declaration for simplifying your .emacs
https://jwiegley.github.io/use-package
GNU General Public License v3.0
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A Useful Recipe: Interactively inspect what `form` `use-package` expands to under various scenarios -- minimal expansion, compilation etc. #1056

Open emacksnotes opened 1 year ago

emacksnotes commented 1 year ago

Not a issue but a recipe ...

I wonder what variables apart from byte-compile-current-file affects the macroexpansion of use-package. If there are other such variables, they can be prompted for and plugged in to the env bindings below.

Slightly formalized the goings on in https://github.com/jwiegley/use-package/issues/1032

(advice-add 'pp-macroexpand-last-sexp :around
        (defun pp-macroexpand-last-sexp--around
        (orig-fun &rest orig-args)
          (pcase-let*
          ((`(,arg)
            orig-args)
           (sexp (pp-last-sexp))
           (env (when (eq 'use-package (car sexp))
              `((byte-compile-current-file ,(yes-or-no-p "Byte compilation"))
                (use-package-expand-minimally ,(yes-or-no-p "Minimal"))))))
        (funcall `(lambda ()
                ,(macroexp-let* `(,@env)
                        `(progn
                           (if ',arg
                           (save-excursion
                             (insert "\n\n")
                             (apply ,orig-fun ',orig-args))
                         (apply ,orig-fun ',orig-args)))))))))

;; (advice-remove 'pp-macroexpand-last-sexp 'pp-macroexpand-last-sexp--around)

Create a quick binding for the above command

(local-set-key (kbd "C-c C-c") #'pp-macroexpand-last-sexp)

Insert the following in to *scratch* buffer

(use-package rainbow-mode
  :functions (rainbow-x-color-luminance)
  :config
  (rainbow-x-color-luminance "cyan"))

(dolist (elt list value)
  (setq value (cons elt value)))

Put the cursor after any of the above two forms and do C-u C-c C-c and see what happens ...

For example, for byte compilation and minimal scenario I get

(progn
  (eval-and-compile
    (declare-function rainbow-x-color-luminance #1="rainbow-mode")
    (eval-when-compile
      (with-demoted-errors "Cannot load rainbow-mode: %S" nil
               (unless
                   (featurep 'rainbow-mode)
                 (load #1# nil t)))))
  (require 'rainbow-mode nil nil)
  (rainbow-x-color-luminance "cyan")
  t)

For no byte-compiled, and minimal scenario, I get

(progn
  (require 'rainbow-mode nil nil)
  (rainbow-x-color-luminance "cyan")
  t)
emacksnotes commented 1 year ago

Here is another variation of the above advice ... This uses eval.

(use-package use-package
  :config (advice-add 'pp-macroexpand-last-sexp :around
              (defun pp-macroexpand-last-sexp--around
              (orig-fun &rest orig-args)
            (pcase-let*
                ((`(,arg)
                  orig-args)
                 (sexp (pp-last-sexp))
                 (env (append
                   (when (eq 'use-package (car sexp))
                     `((byte-compile-current-file ,(yes-or-no-p "Byte compilation"))
                       (use-package-expand-minimally ,(yes-or-no-p "Minimal")))))))
              (eval `(let ,env
                   (if ',arg
                       (save-excursion
                     (insert "\n\n")
                     (apply ',orig-fun ',orig-args))
                     (apply ',orig-fun ',orig-args))))))))
emacksnotes commented 1 year ago

See Emacs Notes: Migrating to use-package—TIP 1: Do NOT use a naive macroexpand to grok a use-package declaration; use this wrapper instead