Re: Closures in Emacs and their usage scenarios.

[Emanuel Berg]

> Here is one example - note that the byte-compiler will warn
> that "the function ‘align-from-left’ is not known to be
> defined." Well, OK.

I think you can shut the byte-compiler up by using
`declare-function', see the source.

Is this the rare case of a mutable variable BTW?

Interesting if so, since it is the only use case I can think
of, maybe except for several functions sharing the same data
(OK, let's say that data won't change).

;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;;   https://dataswamp.org/~incal/emacs-init/align-from-left.el

(require 'cl-lib)

(let ((alf-regexp))
  (defun align-from-left (&optional set-regexp)
    (interactive "p")
    (let ((default-regexp "^\\|[[:punct:]]\\|[[:space:]][[:alnum:]]"))
      (unless (stringp set-regexp)
        (cl-case set-regexp
          ( 4 (setq alf-regexp (read-regexp "regexp: ")))
          (16 (setq alf-regexp default-regexp))
          ( t (unless alf-regexp
                (setq alf-regexp default-regexp) )))))
    (let ((beg (point))
          (re  (or (and (stringp set-regexp) set-regexp)
                    alf-regexp) ))
      (when (re-search-backward re (line-beginning-position) t)
        (while (looking-at "[[:space:]]")
          (forward-char 1) )
        (insert (make-string (- beg (point)) ?\s)) ))))

(declare-function align-from-left nil)
(defalias 'alf #'align-from-left)

(provide 'align-from-left)


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