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

(require 'cl-lib)
(cl-pushnew "." load-path :test #'string=)
(require 'luki-lisp)

;; --------------------------------------------------------------------------

(defun insert-at-col (str col)
  (interactive "s string: \nncol: ")
  (let* ((beg (or (current-column) 0))
         (pad-len (- col beg)))
    (when (< 0 pad-len)
      (insert (make-string pad-len ?\s) str))))

;; --------------------------------------------------------------------------

(let ((push-col 0))
  (defun push-to-col (&optional set-col)
    (interactive "P")
    (if (integerp set-col)
        (setq push-col set-col)
      (if (& set-col (listp set-col))
          (progn
            (setq push-col (or (current-column) 0))
            ($ "done: %s" push-col))
        (let* ((beg (or (current-column) 0))
               (pad-len (- push-col beg)))
          (when (< 0 pad-len)
            (insert (make-string pad-len ?\s))
            (forward-line)
            (unless (looking-at "$")
              (forward-char beg))))))))

(declare-function push-to-col nil)

;; --------------------------------------------------------------------------

(defun eat-space () (i)
  (let ((beg (point))
        (same-line-whitespace " \t"))
    (beginning-of-line)
    (if (looking-at (@f "^[%s]*$" same-line-whitespace))
        (delete-blank-lines)
      (goto-char beg)
      (if (!z (skip-chars-forward same-line-whitespace))
          (delete-region beg (point))
        (delete-horizontal-space)
        (insert-char ?\s)))))

;; --------------------------------------------------------------------------

(let ((alf-re))
  (defun align-from-left (&optional set-re)
    (interactive "p")
    (let ((def-re "^\\|[[:punct:]]\\|[[:space:]][[:alnum:]]"))
      (unless (s set-re)
        (cl-case set-re
          (4  (setq alf-re (read-regexp "regexp: ")))
          (16 (setq alf-re def-re))
          (t  (unless alf-re
                (setq alf-re def-re))))))
    (let ((beg (point))
          (re (or (& (s set-re) set-re) alf-re)))
      (when (re-search-backward re (pos-bol) 'noerror)
        (while (looking-at "[[:space:]]")
          (forward-char))
        (insert (make-string (- beg (point)) ?\s))))))

(declare-function align-from-left nil)

;; --------------------------------------------------------------------------

(<- 'll-align)