geomyidae

gph-mode.el (6509B)

---

 ;;; gph-mode.el --- major mode for gph files  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) Troels Henriksen (athas@sigkill.dk) 2022
 ;;
 ;; URL: gopher://sigkill.dk/1/programming
 ;; Keywords: gopher
 ;; Version: 1.1
 ;; Package-Requires: ((emacs "25.1"))
 
 ;; This file is not part of GNU Emacs.
 
 ;;; License:
 ;; GPL-3+
 
 ;;; Commentary:
 ;; .gph is the map file format used by the geomyidae Gopher daemon.
 ;; This Emacs mode provides basic understanding of the link syntax,
 ;; such that highlighting and folding works properly.  It also
 ;; highlights tab characters in pink because these are not allowed in
 ;; .gph files.
 ;;
 ;; Files with the ".gph" extension are automatically handled by this mode.
 ;;
 ;; For extensions: Define local keybindings in `gph-mode-map'.  Add
 ;; startup functions to `gph-mode-hook'.
 
 ;;; Code:
 
 (eval-when-compile
   (require 'rx))
 
 (defface gph-tabs-face
   '((((class color)) (:background  "hotpink"))
     (t (:reverse-video t)))
   "Face to use for highlighting tabs in Font-Lock mode.")
 
 (defvar gph-tabs 'gph-tabs-face
   "Face to use for highlighting tabs in Font-Lock mode.")
 
 (defvar gph--font-lock-defaults
   (let* ((type-rx '(or "0" "1" "3" "7" "8" "9" "g" "I" "h" "i"))
          (desc-rx '(* (not "|")))
          (path-rx '(* (not "|")))
          (host-rx '(* (not "|")))
          (port-rx '(+ digit))
          (link-rx `(: line-start "[" ,type-rx "|" ,desc-rx "|" ,path-rx "|" ,host-rx "|" ,port-rx "]"))
          (badlink-rx `(: line-start "[" (* anything))))
     `((,(rx-to-string link-rx) 0 font-lock-doc-markup-face)
       (,(rx-to-string badlink-rx) 0 font-lock-warning-face)
       ("\t" 0 gph-tabs))))
 
 (defvar gph-mode-hook nil
   "Hook for `gph-mode'.  Is run whenever the mode is entered.")
 
 (defvar gph-mode-map
   (let ((map (make-keymap)))
     map)
   "Keymap for `gph-mode'.")
 
 ;;;###autoload
 (add-to-list 'auto-mode-alist '("\\.gph" . gph-mode))
 
 ;;;###autoload
 (define-derived-mode gph-mode text-mode "gph"
   "Major mode for .gph files as used by geomyidae."
   (setq-local paragraph-start (concat "^\\[|\\|[ \t]*$\\|" page-delimiter))
   (setq-local paragraph-separate (concat "^\\[\\|[ \t]*$\\|" page-delimiter))
   (setq-local font-lock-defaults '(gph--font-lock-defaults)))
 
 
 (defun gph-insert-link (c label path server port)
 
   "Easily insert a gopher link. You will be prompted for:
 - C:      a character representing the link type (see list below)
 - LABEL:  a string to be used as the link label
 - PATH:   path to the item you wish to link to
 - SERVER: the domain of the server (defaults to 'server')
 - PORT:   port to use (defaults to '70')
 
 the possible options for C are:
   key    type           gopher equivalent
 - f      file           0
 - d      directory      1
 - b      binary         9
 - g      gif            g
 - I      image          I
 - s      search         7
 - h      http           h
 - t      telnet         8
 - e      error          3
 - i      info           i
 
 the resulting link looks something like:
 [0|my file|./file.txt|example.com|70]
 
 see also `gph-generate-link', which converts a gopher url to a link"
 
   (interactive "c[f]ile [d]ir [b]inary [g]if [I]mage [s]earch [h]ttp [t]elnet [e]rror [i]nfo: \nMLabel: \nMPath: \nsServer (server): \nsPort (70): ")
 
   (cond ((char-equal c ?f)
          (insert "[0|"))
         ((char-equal c ?d)
          (insert "[1|"))
         ((char-equal c ?b)
          (insert "[9|"))
         ((char-equal c ?g)
          (insert "[g|"))
         ((char-equal c ?I)
          (insert "[I|"))
         ((char-equal c ?s)
          (insert "[7|"))
         ((char-equal c ?h)
          (insert "[h|"))
         ((char-equal c ?t)
          (insert "[8|"))
         ((char-equal c ?e)
          (insert "[3|"))
         ((char-equal c ?i)
          (insert "[i|")))
   (insert (concat label "|" path "|"
                   (if (string-equal server "")
                       "server" server)
                   "|"
                   (if (string-equal port "")
                       "70" port)
                   "]")))
 
 ;; these are some functions that break up a url
 ;; for when automagically transforming a gopher:// url
 ;; into a proper geomyidae link
 
 (defun gph--remove-proto (url)
   "Remove 'gopher://' from a URL string."
    (string-trim url "gopher://" ""))
 
 (defun gph--get-domain (url)
   "Return only the domain name of a URL."
 (car (string-split (gph--remove-proto url) "/")))
 
 (defun gph--get-path (url)
   "Return only the resource path of the URL"
   (string-trim-left
    (string-remove-prefix (gph--get-domain url)
                          (gph--remove-proto url))
    "/[^z-a]"))
 
 (defun gph--get-type (url)
   "Attempt to get the link type of the  URL (like 0 for file, 1 for dir etc)."
   (caddr (string-split
           (string-remove-prefix (gph--get-domain url)
                                 (gph--remove-proto url))
           "")))
 
 (defun gph-url-to-link (url label)
   "Convert a gopher:// or http:// url to the geomyidae link format.
 this function prompts you for a URL, then for a link label. it tries to
 parse the URL you provide and output a correct link to that resource.
 
 The URL tries to default to whatever is in your clipboard. I don't think
 this works in non-graphical environments.
 
   gopher://example.com/0/some/file.txt
 becomes
   [0|my label|/some/file.txt|example.com|70]"
 
   ;; this interactive funciton is kinda big but it works okay
   (interactive (let* ((selection (string-truncate-left (gui-get-selection) 70))
                       (prompt (if (gui-get-selection)
                                   (format "URL (%s): "  selection)
                                 "URL: "))
                       (url (read-string prompt nil nil selection nil))
                       (label (read-string "Label: " nil nil nil nil)))
                  (list url label)))
 
   (if (or (string-prefix-p "gopher://"  url 1)
           (string-prefix-p "gophers://" url 1))
   (insert (concat
            "[" (gph--get-type url)
            "|" label
            "|" (gph--get-path url)
            "|" (gph--get-domain url)
            "|70]"))
 
   ;; else, it's probably an http:// link
   (insert (concat
            "[h|" label "|URL:" url "|server|70]"))))
 
 ;;gph-mode-map
 (define-key gph-mode-map (kbd "C-c C-,") 'gph-insert-link)
 (define-key gph-mode-map (kbd "C-c C-l") 'gph-url-to-link)
 
 ;; add a reminder about these bindings in the minibuffer
 (add-hook 'gph-mode-hook
           (lambda ()
             (message "[C-c C-,] insert link. [C-c C-l] convert URL to link. ")))
 
 (provide 'gph-mode)
 
 ;;; gph-mode.el ends here