doomemacs/core/core-editor.el

;;; core-editor.el -*- lexical-binding: t; -*-

(defvar doom-detect-indentation-excluded-modes '(fundamental-mode so-long-mode)
  "A list of major modes in which indentation should be automatically
detected.")

(defvar-local doom-inhibit-indent-detection nil
  "A buffer-local flag that indicates whether `dtrt-indent' should try to detect
indentation settings or not. This should be set by editorconfig if it
successfully sets indent_style/indent_size.")

(defvar-local doom-large-file-p nil)
(put 'doom-large-file-p 'permanent-local t)

(defvar doom-large-file-size-alist '(("." . 1.0))
  "An alist mapping regexps (like `auto-mode-alist') to filesize thresholds.

If a file is opened and discovered to be larger than the threshold, Doom
performs emergency optimizations to prevent Emacs from hanging, crashing or
becoming unusably slow.

These thresholds are in MB, and is used by `doom--optimize-for-large-files-a'.")

(defvar doom-large-file-excluded-modes
  '(so-long-mode special-mode archive-mode tar-mode jka-compr
    git-commit-mode image-mode doc-view-mode doc-view-mode-maybe
    ebrowse-tree-mode pdf-view-mode tags-table-mode)
  "Major modes that `doom-check-large-file-h' will ignore.")


;;
;;; File handling

(defadvice! doom--prepare-for-large-files-a (size _ filename &rest _)
  "Sets `doom-large-file-p' if the file is considered large.

Uses `doom-large-file-size-alist' to determine when a file is too large. When
`doom-large-file-p' is set, other plugins can detect this and reduce their
runtime costs (or disable themselves) to ensure the buffer is as fast as
possible."
  :before #'abort-if-file-too-large
  (and (numberp size)
       (> size
          (* 1024 1024
             (assoc-default filename doom-large-file-size-alist
                            #'string-match-p)))
       (setq doom-large-file-p size)))

(defadvice! doom--optimize-for-large-files-a (&rest _)
  "Trigger `so-long-minor-mode' if the file is large."
  :after #'after-find-file
  (when (and doom-large-file-p buffer-file-name)
    (if (memq major-mode doom-large-file-excluded-modes)
        (setq doom-large-file-p nil)
      (when (fboundp 'so-long-minor-mode) ; in case the user disabled it
        (so-long-minor-mode +1))
      (message "Large file detected! Cutting a few corners to improve performance..."))))

;; Resolve symlinks when opening files, so that any operations are conducted
;; from the file's true directory (like `find-file').
(setq find-file-visit-truename t
      vc-follow-symlinks t)

;; Disable the warning "X and Y are the same file". It's fine to ignore this
;; warning as it will redirect you to the existing buffer anyway.
(setq find-file-suppress-same-file-warnings t)

;; Create missing directories when we open a file that doesn't exist under a
;; directory tree that may not exist.
(add-hook! 'find-file-not-found-functions
  (defun doom-create-missing-directories-h ()
    "Automatically create missing directories when creating new files."
    (unless (file-remote-p buffer-file-name)
      (let ((parent-directory (file-name-directory buffer-file-name)))
        (and (not (file-directory-p parent-directory))
             (y-or-n-p (format "Directory `%s' does not exist! Create it?"
                               parent-directory))
             (progn (make-directory parent-directory 'parents)
                    t))))))

;; Don't generate backups or lockfiles. While auto-save maintains a copy so long
;; as a buffer is unsaved, backups create copies once, when the file is first
;; written, and never again until it is killed and reopened. This is better
;; suited to version control, and I don't want world-readable copies of
;; potentially sensitive material floating around our filesystem.
(setq create-lockfiles nil
      make-backup-files nil
      ;; But in case the user does enable it, some sensible defaults:
      version-control t     ; number each backup file
      backup-by-copying t   ; instead of renaming current file (clobbers links)
      delete-old-versions t ; clean up after itself
      kept-old-versions 5
      kept-new-versions 5
      backup-directory-alist (list (cons "." (concat doom-cache-dir "backup/"))))

;; But turn on auto-save, so we have a fallback in case of crashes or lost data.
;; Use `recover-file' or `recover-session' to recover them.
(setq auto-save-default t
      ;; Don't auto-disable auto-save after deleting big chunks. Kind of
      ;; defaults the purpose of a fallback in case of crashes.
      auto-save-include-big-deletions t
      ;; ...but have directories set up in case we use it.
      auto-save-list-file-prefix (concat doom-cache-dir "autosave/")
      auto-save-file-name-transforms (list (list ".*" auto-save-list-file-prefix t)))

(add-hook! 'after-save-hook
  (defun doom-guess-mode-h ()
    "Guess mode when saving a file in `fundamental-mode'."
    (when (eq major-mode 'fundamental-mode)
      (let ((buffer (or (buffer-base-buffer) (current-buffer))))
        (and (buffer-file-name buffer)
             (eq buffer (window-buffer (selected-window))) ; only visible buffers
             (set-auto-mode))))))


;;
;;; Formatting

;; Favor spaces over tabs. Pls dun h8, but I think spaces (and 4 of them) is a
;; more consistent default than 8-space tabs. It can be changed on a per-mode
;; basis anyway (and is, where tabs are the canonical style, like go-mode).
(setq-default indent-tabs-mode nil
              tab-width 4)

;; Only indent the line when at BOL or in a line's indentation. Anywhere else,
;; insert literal indentation.
(setq-default tab-always-indent nil)

;; Make `tabify' and `untabify' only affect indentation. Not tabs/spaces in the
;; middle of a line.
(setq tabify-regexp "^\t* [ \t]+")

;; An archaic default in the age of widescreen 4k displays? I disagree. We still
;; frequently split our terminals and editor frames, or have them side-by-side,
;; using up more of that newly available horizontal real-estate.
(setq-default fill-column 80)

;; Continue wrapped words at whitespace, rather than in the middle of a word.
(setq-default word-wrap t)
;; ...but don't do any wrapping by default. It's expensive. Enable
;; `visual-line-mode' if you want soft line-wrapping. `auto-fill-mode' for hard
;; line-wrapping.
(setq-default truncate-lines t)
;; If enabled (and `truncate-lines' was disabled), soft wrapping no longer
;; occurs when that window is less than `truncate-partial-width-windows'
;; characters wide. We don't need this, and it's extra work for Emacs otherwise,
;; so off it goes.
(setq truncate-partial-width-windows nil)

;; This was a widespread practice in the days of typewriters. I actually prefer
;; it when writing prose with monospace fonts, but it is obsolete otherwise.
(setq sentence-end-double-space nil)

;; The POSIX standard defines a line is "a sequence of zero or more non-newline
;; characters followed by a terminating newline", so files should end in a
;; newline. Windows doesn't respect this (because it's Windows), but we should,
;; since programmers' tools tend to be POSIX compliant.
(setq require-final-newline t)

;; Default to soft line-wrapping in text modes. It is more sensibile for text
;; modes, even if hard wrapping is more performant.
(add-hook 'text-mode-hook #'visual-line-mode)


;;
;;; Clipboard / kill-ring

;; Cull duplicates in the kill ring to reduce bloat and make the kill ring
;; easier to peruse (with `counsel-yank-pop' or `helm-show-kill-ring'.
(setq kill-do-not-save-duplicates t)

;; Allow UTF or composed text from the clipboard, even in the terminal or on
;; non-X systems (like Windows or macOS), where only `STRING' is used.
(setq x-select-request-type '(UTF8_STRING COMPOUND_TEXT TEXT STRING))


;;
;;; Extra file extensions to support

(nconc
 auto-mode-alist
 '(("/LICENSE\\'" . text-mode)
   ("\\.log\\'" . text-mode)
   ("rc\\'" . conf-mode)
   ("\\.\\(?:hex\\|nes\\)\\'" . hexl-mode)))


;;
;;; Built-in plugins

(use-package! autorevert
  ;; revert buffers when their files/state have changed
  :hook (focus-in . doom-auto-revert-buffers-h)
  :hook (after-save . doom-auto-revert-buffers-h)
  :hook (doom-switch-buffer . doom-auto-revert-buffer-h)
  :hook (doom-switch-window . doom-auto-revert-buffer-h)
  :config
  (setq auto-revert-verbose t ; let us know when it happens
        auto-revert-use-notify nil
        auto-revert-stop-on-user-input nil
        ;; Only prompts for confirmation when buffer is unsaved.
        revert-without-query (list "."))

  ;; `auto-revert-mode' and `global-auto-revert-mode' would, normally, abuse the
  ;; heck out of inotify handles _or_ aggresively poll your buffer list every X
  ;; seconds. Too many inotify handles can grind Emacs to a halt if you preform
  ;; expensive or batch processes on files outside of Emacs (e.g. their mtime
  ;; changes), and polling your buffer list is terribly inefficient as your
  ;; buffer list grows into the tens or hundreds.
  ;;
  ;; So Doom uses a different strategy: we lazily auto revert buffers when the
  ;; user a) saves a file, b) switches to a buffer (or its window), or c) you
  ;; focus Emacs (after using another program). This way, Emacs only ever has to
  ;; operate on, at minimum, a single buffer and, at maximum, X buffers, where X
  ;; is the number of open windows (which is rarely, if ever, over 10).
  (defun doom-auto-revert-buffer-h ()
    "Auto revert current buffer, if necessary."
    (unless (or auto-revert-mode (active-minibuffer-window))
      (let ((auto-revert-mode t))
        (auto-revert-handler))))

  (defun doom-auto-revert-buffers-h ()
    "Auto revert stale buffers in visible windows, if necessary."
    (dolist (buf (doom-visible-buffers))
      (with-current-buffer buf
        (doom-auto-revert-buffer-h)))))


(use-package! recentf
  ;; Keep track of recently opened files
  :defer-incrementally easymenu tree-widget timer
  :hook (doom-first-file . recentf-mode)
  :commands recentf-open-files
  :config
  (defun doom--recent-file-truename (file)
    (if (or (file-remote-p file nil t)
            (not (file-remote-p file)))
        (file-truename file)
      file))
  (setq recentf-filename-handlers
        '(;; Text properties inflate the size of recentf's files, and there is
          ;; no purpose in persisting them, so we strip them out.
          substring-no-properties
          ;; Resolve symlinks of local files. Otherwise we get duplicate
          ;; entries opening symlinks.
          doom--recent-file-truename
          ;; Replace $HOME with ~, which is more portable, and reduces how much
          ;; horizontal space the recentf listing uses to list recent files.
          abbreviate-file-name)
        recentf-save-file (concat doom-cache-dir "recentf")
        recentf-auto-cleanup 'never
        recentf-max-menu-items 0
        recentf-max-saved-items 200)

  (add-hook! '(doom-switch-window-hook write-file-functions)
    (defun doom--recentf-touch-buffer-h ()
      "Bump file in recent file list when it is switched or written to."
      (when buffer-file-name
        (recentf-add-file buffer-file-name))
      ;; Return nil for `write-file-functions'
      nil))

  (add-hook! 'dired-mode-hook
    (defun doom--recentf-add-dired-directory-h ()
      "Add dired directory to recentf file list."
      (recentf-add-file default-directory)))

  (add-hook 'kill-emacs-hook #'recentf-cleanup)
  (advice-add #'recentf-load-list :around #'doom-shut-up-a))


(use-package! savehist
  ;; persist variables across sessions
  :defer-incrementally custom
  :hook (doom-first-input . savehist-mode)
  :init
  (setq savehist-file (concat doom-cache-dir "savehist"))
  :config
  (setq savehist-save-minibuffer-history t
        savehist-autosave-interval nil     ; save on kill only
        savehist-additional-variables
        '(kill-ring                        ; persist clipboard
          mark-ring global-mark-ring       ; persist marks
          search-ring regexp-search-ring)) ; persist searches
  (add-hook! 'savehist-save-hook
    (defun doom-unpropertize-kill-ring-h ()
      "Remove text properties from `kill-ring' for a smaller savehist file."
      (setq kill-ring (cl-loop for item in kill-ring
                               if (stringp item)
                               collect (substring-no-properties item)
                               else if item collect it)))))


(use-package! saveplace
  ;; persistent point location in buffers
  :hook (doom-first-file . save-place-mode)
  :init
  (setq save-place-file (concat doom-cache-dir "saveplace")
        save-place-limit 100)
  :config
  (defadvice! doom--recenter-on-load-saveplace-a (&rest _)
    "Recenter on cursor when loading a saved place."
    :after-while #'save-place-find-file-hook
    (if buffer-file-name (ignore-errors (recenter))))

  (defadvice! doom--inhibit-saveplace-in-long-files-a (orig-fn &rest args)
    :around #'save-place-to-alist
    (unless doom-large-file-p
      (apply orig-fn args)))

  (defadvice! doom--dont-prettify-saveplace-cache-a (orig-fn)
    "`save-place-alist-to-file' uses `pp' to prettify the contents of its cache.
`pp' can be expensive for longer lists, and there's no reason to prettify cache
files, so we replace calls to `pp' with the much faster `prin1'."
    :around #'save-place-alist-to-file
    (letf! ((#'pp #'prin1)) (funcall orig-fn))))


(use-package! server
  :when (display-graphic-p)
  :after-call pre-command-hook after-find-file focus-out-hook
  :defer 1
  :init
  (when-let (name (getenv "EMACS_SERVER_NAME"))
    (setq server-name name))
  :config
  (unless (server-running-p)
    (server-start)))


;;
;;; Packages

(use-package! better-jumper
  :hook (doom-first-input . better-jumper-mode)
  :commands doom-set-jump-a doom-set-jump-maybe-a doom-set-jump-h
  :preface
  ;; REVIEW Suppress byte-compiler warning spawning a *Compile-Log* buffer at
  ;; startup. This can be removed once gilbertw1/better-jumper#2 is merged.
  (defvar better-jumper-local-mode nil)
  :init
  (global-set-key [remap evil-jump-forward]  #'better-jumper-jump-forward)
  (global-set-key [remap evil-jump-backward] #'better-jumper-jump-backward)
  (global-set-key [remap xref-pop-marker-stack] #'better-jumper-jump-backward)
  :config
  (defun doom-set-jump-a (orig-fn &rest args)
    "Set a jump point and ensure ORIG-FN doesn't set any new jump points."
    (better-jumper-set-jump (if (markerp (car args)) (car args)))
    (let ((evil--jumps-jumping t)
          (better-jumper--jumping t))
      (apply orig-fn args)))

  (defun doom-set-jump-maybe-a (orig-fn &rest args)
    "Set a jump point if ORIG-FN returns non-nil."
    (let ((origin (point-marker))
          (result
           (let* ((evil--jumps-jumping t)
                  (better-jumper--jumping t))
             (apply orig-fn args))))
      (unless result
        (with-current-buffer (marker-buffer origin)
          (better-jumper-set-jump
           (if (markerp (car args))
               (car args)
             origin))))
      result))

  (defun doom-set-jump-h ()
    "Run `better-jumper-set-jump' but return nil, for short-circuiting hooks."
    (better-jumper-set-jump)
    nil)

  ;; Creates a jump point before killing a buffer. This allows you to undo
  ;; killing a buffer easily (only works with file buffers though; it's not
  ;; possible to resurrect special buffers).
  (advice-add #'kill-current-buffer :around #'doom-set-jump-a)

  ;; Create a jump point before jumping with imenu.
  (advice-add #'imenu :around #'doom-set-jump-a))


(use-package! dtrt-indent
  ;; Automatic detection of indent settings
  :when doom-interactive-p
  :hook ((change-major-mode-after-body read-only-mode) . doom-detect-indentation-h)
  :config
  (defun doom-detect-indentation-h ()
    (unless (or (not after-init-time)
                doom-inhibit-indent-detection
                doom-large-file-p
                (memq major-mode doom-detect-indentation-excluded-modes)
                (member (substring (buffer-name) 0 1) '(" " "*")))
      ;; Don't display messages in the echo area, but still log them
      (let ((inhibit-message (not doom-debug-p)))
        (dtrt-indent-mode +1))))

  ;; Enable dtrt-indent even in smie modes so that it can update `tab-width',
  ;; `standard-indent' and `evil-shift-width' there as well.
  (setq dtrt-indent-run-after-smie t)
  ;; Reduced from the default of 5000 for slightly faster analysis
  (setq dtrt-indent-max-lines 2000)

  ;; always keep tab-width up-to-date
  (push '(t tab-width) dtrt-indent-hook-generic-mapping-list)

  (defvar dtrt-indent-run-after-smie)
  (defadvice! doom--fix-broken-smie-modes-a (orig-fn arg)
    "Some smie modes throw errors when trying to guess their indentation, like
`nim-mode'. This prevents them from leaving Emacs in a broken state."
    :around #'dtrt-indent-mode
    (let ((dtrt-indent-run-after-smie dtrt-indent-run-after-smie))
      (letf! ((defun symbol-config--guess (beg end)
                (funcall symbol-config--guess beg (min end 10000)))
              (defun smie-config-guess ()
                (condition-case e (funcall smie-config-guess)
                  (error (setq dtrt-indent-run-after-smie t)
                         (message "[WARNING] Indent detection: %s"
                                  (error-message-string e))
                         (message ""))))) ; warn silently
        (funcall orig-fn arg)))))


(use-package! helpful
  ;; a better *help* buffer
  :commands helpful--read-symbol
  :init
  (global-set-key [remap describe-function] #'helpful-callable)
  (global-set-key [remap describe-command]  #'helpful-command)
  (global-set-key [remap describe-variable] #'helpful-variable)
  (global-set-key [remap describe-key]      #'helpful-key)
  (global-set-key [remap describe-symbol]   #'helpful-symbol)

  (defun doom-use-helpful-a (orig-fn &rest args)
    "Force ORIG-FN to use helpful instead of the old describe-* commands."
    (letf! ((#'describe-function #'helpful-function)
            (#'describe-variable #'helpful-variable))
      (apply orig-fn args)))

  (after! apropos
    ;; patch apropos buttons to call helpful instead of help
    (dolist (fun-bt '(apropos-function apropos-macro apropos-command))
      (button-type-put
       fun-bt 'action
       (lambda (button)
         (helpful-callable (button-get button 'apropos-symbol)))))
    (dolist (var-bt '(apropos-variable apropos-user-option))
      (button-type-put
       var-bt 'action
       (lambda (button)
         (helpful-variable (button-get button 'apropos-symbol)))))))


;;;###package imenu
(add-hook 'imenu-after-jump-hook #'recenter)


(use-package! smartparens
  ;; Auto-close delimiters and blocks as you type. It's more powerful than that,
  ;; but that is all Doom uses it for.
  :hook (doom-first-buffer . smartparens-global-mode)
  :commands sp-pair sp-local-pair sp-with-modes sp-point-in-comment sp-point-in-string
  :config
  ;; smartparens recognizes `slime-mrepl-mode', but not `sly-mrepl-mode', so...
  (add-to-list 'sp-lisp-modes 'sly-mrepl-mode)
  ;; Load default smartparens rules for various languages
  (require 'smartparens-config)
  ;; Overlays are too distracting and not terribly helpful. show-parens does
  ;; this for us already (and is faster), so...
  (setq sp-highlight-pair-overlay nil
        sp-highlight-wrap-overlay nil
        sp-highlight-wrap-tag-overlay nil)
  (with-eval-after-load 'evil
    ;; But if someone does want overlays enabled, evil users will be stricken
    ;; with an off-by-one issue where smartparens assumes you're outside the
    ;; pair when you're really at the last character in insert mode. We must
    ;; correct this vile injustice.
    (setq sp-show-pair-from-inside t)
    ;; ...and stay highlighted until we've truly escaped the pair!
    (setq sp-cancel-autoskip-on-backward-movement nil))

  ;; The default is 100, because smartparen's scans are relatively expensive
  ;; (especially with large pair lists for some modes), we reduce it, as a
  ;; better compromise between performance and accuracy.
  (setq sp-max-prefix-length 25)
  ;; No pair has any business being longer than 4 characters; if they must, set
  ;; it buffer-locally. It's less work for smartparens.
  (setq sp-max-pair-length 4)
  ;; This isn't always smart enough to determine when we're in a string or not.
  ;; See https://github.com/Fuco1/smartparens/issues/783.
  (setq sp-escape-quotes-after-insert nil)

  ;; Silence some harmless but annoying echo-area spam
  (dolist (key '(:unmatched-expression :no-matching-tag))
    (setf (alist-get key sp-message-alist) nil))

  (add-hook! 'minibuffer-setup-hook
    (defun doom-init-smartparens-in-minibuffer-maybe-h ()
      "Enable `smartparens-mode' in the minibuffer, during `eval-expression',
`pp-eval-expression' or `evil-ex'."
      (and (memq this-command '(eval-expression pp-eval-expression evil-ex))
           smartparens-global-mode
           (smartparens-mode))))

  ;; You're likely writing lisp in the minibuffer, therefore, disable these
  ;; quote pairs, which lisps doesn't use for strings:
  (sp-local-pair 'minibuffer-inactive-mode "'" nil :actions nil)
  (sp-local-pair 'minibuffer-inactive-mode "`" nil :actions nil)

  ;; Smartparens breaks evil-mode's replace state
  (defvar doom-buffer-smartparens-mode nil)
  (add-hook! 'evil-replace-state-exit-hook
    (defun doom-enable-smartparens-mode-maybe-h ()
      (when doom-buffer-smartparens-mode
        (turn-on-smartparens-mode)
        (kill-local-variable 'doom-buffer-smartparens-mode))))
  (add-hook! 'evil-replace-state-entry-hook
    (defun doom-disable-smartparens-mode-maybe-h ()
      (when smartparens-mode
        (setq-local doom-buffer-smartparens-mode t)
        (turn-off-smartparens-mode)))))


(use-package! so-long
  :hook (doom-first-file . global-so-long-mode)
  :config
  (setq so-long-threshold 400) ; reduce false positives w/ larger threshold
  ;; Don't disable syntax highlighting and line numbers, or make the buffer
  ;; read-only, in `so-long-minor-mode', so we can have a basic editing
  ;; experience in them, at least. It will remain off in `so-long-mode',
  ;; however, because long files have a far bigger impact on Emacs performance.
  (delq! 'font-lock-mode so-long-minor-modes)
  (delq! 'display-line-numbers-mode so-long-minor-modes)
  (delq! 'buffer-read-only so-long-variable-overrides 'assq)
  ;; ...but at least reduce the level of syntax highlighting
  (add-to-list 'so-long-variable-overrides '(font-lock-maximum-decoration . 1))
  ;; ...and insist that save-place not operate in large/long files
  (add-to-list 'so-long-variable-overrides '(save-place-alist . nil))
  ;; Text files could possibly be too long too
  (add-to-list 'so-long-target-modes 'text-mode)
  ;; But disable everything else that may be unnecessary/expensive for large
  ;; or wide buffers.
  (appendq! so-long-minor-modes
            '(flycheck-mode
              flyspell-mode
              spell-fu-mode
              eldoc-mode
              smartparens-mode
              highlight-numbers-mode
              better-jumper-local-mode
              ws-butler-mode
              auto-composition-mode
              undo-tree-mode
              highlight-indent-guides-mode
              hl-fill-column-mode))
  (defun doom-buffer-has-long-lines-p ()
    ;; HACK Fix #2183: `so-long-detected-long-line-p' tries to parse comment
    ;;      syntax, but in some buffers comment state isn't initialized,
    ;;      leading to a wrong-type-argument: stringp error.
    (let ((so-long-skip-leading-comments (bound-and-true-p comment-use-syntax))
          ;; HACK If visual-line-mode is on, then false positives are more
          ;;      likely, so up the threshold. More so in text-mode, since long
          ;;      paragraphs are the norm.
          (so-long-threshold
           (if visual-line-mode
               (* so-long-threshold
                  (if (derived-mode-p 'text-mode)
                      4
                    2))
             so-long-threshold)))
      (so-long-detected-long-line-p)))
  (setq so-long-predicate #'doom-buffer-has-long-lines-p))


(use-package! ws-butler
  ;; a less intrusive `delete-trailing-whitespaces' on save
  :hook (doom-first-buffer . ws-butler-global-mode)
  :config
  ;; ws-butler normally preserves whitespace in the buffer (but strips it from
  ;; the written file). While sometimes convenient, this behavior is not
  ;; intuitive. To the average user it looks like whitespace cleanup is failing,
  ;; which causes folks to redundantly install their own.
  (setq ws-butler-keep-whitespace-before-point nil))

(provide 'core-editor)
;;; core-editor.el ends here