Re: The definition of orig-fn.

[Emanuel Berg]

Hongyi Zhao wrote:

> Without further keyboard remapping, this scheme will require
> at least two keystrokes to complete a candidate insertion.
> I think abo-abo's customized function is just for solving
> this type of problem: One keystroke for one
> candidate insertion.

I don't know if/how related this is, but take a look at this
[code last - yes, I see I should fix the initial comments ...]

Anyway it works like this, it presents you with shortcuts to
shown alternatives - the shortcuts are ?\r ?\s ?\t ... and
so on.

But if you don't hit a shortcut but instead hit, say, the
letter "l", that letter will be inserted instead.

So if you, for example, have the man page ls(1) open you will
be presented with

  [ RET:ls ]

You can then hit RET to go to the ls man page buffer. But you
can also type "ls" just as you would with

  M-x ls RET

and it doesn't require more keystrokes than that.

Very clever if I may, only bummer was I could never find
another use case but the man pages. A good one by all means
but nonetheless ...

;;; buc.el --- move between buffers based on category -*- lexical-binding: t
;;;
;;; Author: Emanuel Berg (incal) <moasenwood@zoho.eu>
;;; Created: 2021-05-23
;;; Keywords: docs, files
;;; License: GPL3+
;;; Package-Requires: ((cl-lib "1.0"))
;;; URL: https://dataswamp.org/~incal/emacs-init/buc.el
;;; Version: 1.0.4
;;;
;;; Commentary:
;;;
;;; This package enables you to move between similar buffers.
;;; So far I have only found one use case for it, namely
;;; accessing man pages - try `man-buc' below.
;;;
;;; The general idea behind the interface is to present
;;; alternatives based on your recent answers to the same
;;; questions. The alternatives are sorted to present you with
;;; the most relevant one first. You pick an alternative by
;;; hitting a single key. If your desired choice is not among
;;; the alternatives, start typing, that will bypass the
;;; interface and the default interface will be used as
;;; a fallback. (But technically it is not a fallback, rather
;;; the interfaces are cooperating covering different parts of
;;; one problem.)
;;;
;;; Note that If you count the number of keypresses you see
;;; the advantage with this package. When the buc interface is
;;; used, the count is much lower, since making a choice
;;; involves hitting a single key or combination. But even
;;; when it is not used, the count still is not higher than
;;; what you would use anyway, since the default interface
;;; immediately comes to life and utilizes the first keydown
;;; as its first input char. Again, try `man-buc' to see how
;;; it works first hand.
;;;
;;; Or take a look at this screenshot:
;;;
;;;   https://dataswamp.org/~incal/dumps/buc.png
;;;
;;; The principle behind the interface is similar to that of
;;; a computer hardware memory cache: proximity in space and
;;; time, with updates on every single access.
;;;
;;; The interface is an hybrid between the GUI and CLI style,
;;; only the GUI "icons" are here words! Some say icons are
;;; more intuitive than words. Well, that is were we agree to
;;; disagree - perhaps that holds for infants but not to
;;; adults who have spent a HUGE part of their life reading
;;; and writing.
;;;
;;; Because we believe intuition is an acquired skill - just
;;; like everything else.
;;;
;;; Code:

(require 'cl-lib)

(defvar nav-keys     nil "The keys used to select buffers.")
(defvar nav-keys-str nil "Descriptions of the buffer-select keys.")

(setq nav-keys    '(?\r ?\s ?\t ?\d ?\C-j ?\C-k ?\C-l ?\C-u ?\C-o ?\C-p))
(setq nav-keys-str (split-string (key-description nav-keys)))

(defun buffer-names ()
  "Get the names of all open buffers, as strings."
  (mapcar #'buffer-name (buffer-list)) )

(defun extract-strings (strings match)
  "From STRINGS, get a list with the parts that MATCH."
  (remove nil
    (mapcar
     (lambda (s) (when (string-match match s)
                   (match-string 1 s) ))
     strings) ))

(defun get-ps (names)
  "Make the prompt-string, with NAMES."
  (let ((k -1)
        (s " [") )
    (dolist (e names (concat s "] "))
      (setq s (format "%s %s:%s "
                      s (nth (cl-incf k) nav-keys-str) e) ))))

(defun navigate-buffer-category (prefix &optional bad-key &rest args)
  "Display all buffers that start with PREFIX.
If none of the offered buffers are chosen by the user's keystroke,
evaluate (BAD-KEY ARGS)."
  (let ((pages (extract-strings (buffer-names)
                                (format "%s%s" prefix "\\(.*\\)\\*") )))
    (if pages
        (let*((ps         (get-ps pages))
              (key        (read-key ps))
              (page-index (cl-position key nav-keys))
              (page       (when page-index
                            (nth page-index pages)) ))
          (if (= key 7)
              (message "quit")
            (if page
                (switch-to-buffer (format "%s%s*" prefix page))
              (when bad-key
                (apply bad-key `(,@args ,key)) ))))
      (if bad-key
          (apply bad-key args)
        (error "Empty category and no fallback function") ))))

(defun switch-to-type (ps fun &optional key)
  "Ask for a string with the prompt-string PS.
Use the string as input to FUN.
If KEY, it'll be the first KEY of the string, auto-inserted."
  (apply fun
         (list (read-string ps
                            (when key
                              (char-to-string key))
                            nil) )))

(defun man-buc ()
  "Show man pages.
If you start typing, you get the common prompt."
  (interactive)
  (navigate-buffer-category "*Man "
                            #'switch-to-type
                            "[buc] man page: "
                            'man) )

(provide 'buc)
;;; buc.el ends here

-- 
underground experts united
https://dataswamp.org/~incal