diff --git a/lisp/info.el b/lisp/info.el index 035dff66e75..f7153af5b26 100644 --- a/lisp/info.el +++ b/lisp/info.el @@ -5510,6 +5510,339 @@ info--manual-names Info-directory-list (mapcar #'car Info-suffix-list)))))))) +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;; This code below provides links of symbols (functions, variables, +;; faces) within Emacs' Info viewer to their builtin help +;; documentation. This linking is done, when the symbol names in +;; texinfo documentations (like the Emacs- and Elisp manual) are + +;; 1. Quoted symbol names like `quoted-symbol' or: + +;; 2. Function names are prefixed by M-x, for example M-x +;; function-name or are quoted and prefixed like `M-x function-name'. + +;; 3. Function names appearing behind the following forms, which +;; occur, for example, in the Elisp manual: + +;; -- Special Form: function-name +;; -- Command: ... +;; -- Function: ... +;; -- Macro: ... + +;; 4. And variables names behind the following text: + +;; -- User Option: variable-name +;; -- Variable: ... + +;; In any case all symbol names must be known to Emacs, which means it +;; is either a built-in, or its Lisp package is loaded in the current +;; Emacs session, or the symbol is auto-loaded. + +;; You can follow the additional links with the usual Info +;; keybindings. The customisation variable +;; `mouse-1-click-follows-link' is influencing the clicking behavior +;; (and the tooltips) of the links, the variable's default is 450 +;; (milli seconds) setting it to nil means only clicking with mouse-2 +;; is following the link (hint: Drew Adams). + +;; The link color of symbols - referencing their builtin documentation +;; - is distinct from links which are referencing further Info +;; documentation. + +;; Below code is checking if Info documents are relevant Elisp and +;; Emacs related files to avoid false positives. Please see the +;; customization variable `info-none-emacs-or-elisp-documents'. + +;; The code uses mostly mechanisms from Emacs' lisp/help-mode.el file. + + + +(require 'button) +(require 'cl-lib) +(require 'help-mode) ;redundant? +(require 'cl-seq) + +(defcustom info-make-xref-flag t + "Non-nil means create symbol links in info buffers. +Please see the function `info-make-xrefs' for further +information." + :type '(choice (const :tag "Create links" t) + (const :tag "Do not link" nil)) + :version "30.1" + :group 'info) + +;; We need to initalise Info-directory-list first. +(info-initialize) +;; Before declaring the following: +(defvar info-emacs-info-dir-content + (mapcar 'file-name-nondirectory ;'file-name-sans-extension + (directory-files + (car + ;; search for the main Emacs' info/ directory + (cl-member "[^.]emacs" Info-directory-list :test 'string-match-p)) + ;; don't list "." and ".." + t "[^.]$")) + "List of file names in Emacs' own info/ directory.") + +;; FIXME: Turn into regexp list? Hint Stefan Monier or switch to alist +;; with explanation of file name? +(defcustom info-none-emacs-or-elisp-documents + '("aarm2012" ; Stefan: Ada manual, Elpa archive + "arm2012" ; Stefan: Ada manual + "sicp" ; T.V: Structure and Interpretation of Computer Programs, + ; Melpa archive + ) + "List of all none GNU Emacs or Elisp documentation. +Or other documents not to be checked for linking to their help +documentation. The list must contain only the base name of the +files (without their file name extension \".info\")." + :type '(repeat string) + :version "30.1" + :group 'info) + +(defun info-check-docu-p () + "Check if the current info file is relevant to Emacs. +That means `Info-current-file' is either found in Emacs' info/ +directory or in `package-user-dir' and is not included in the +`info-none-emacs-or-elisp-documents' list." + (let* ((ifile Info-current-file) + (ifi (when ifile + (file-name-sans-extension + (file-name-nondirectory ifile)))) + (pdir (when (boundp 'package-user-dir) + (expand-file-name + package-user-dir))) + (ifiles info-emacs-info-dir-content) + (ndocu info-none-emacs-or-elisp-documents)) + (and ifile + (or (assoc-string (concat ifi ".info") ifiles) + ;; info files might be archived! + (assoc-string (concat ifi ".info.gz") ifiles) + (when pdir (string-match pdir ifile))) + (not (assoc-string ifi ndocu))))) + +;; FIXME: what are these variables for, suppress compiler warnings? +(defvar describe-symbol-backends) ;from help-mode.el +(defvar help-xref-following) ;dito + +;; This toggles the complete linking process +(when info-make-xref-flag + (add-hook 'Info-selection-hook 'info-make-xrefs)) + +(defface info-color + '((t (:inherit font-lock-doc-face + ;; font-lock-preprocessor-face ; similar to link face (default) + ;; font-lock-builtin-face ; similar (default Emacs) + ;; font-lock-function-name-face ; similar (default) + ;; info-face + ))) + "Face for the `symbol' reference items in `info' nodes." + :group 'info-colors) + +;; Button types + +(define-button-type 'info + 'link t ;for Info-next-reference-or-link + 'follow-link t + 'face 'info-color + 'action #'info-button-action) + +(define-button-type 'info-function + :supertype 'info + 'info-function 'describe-function + 'info-echo (purecopy "mouse-2, RET: describe this function")) + +(define-button-type 'info-variable + :supertype 'info + 'info-function 'describe-variable + 'info-echo (purecopy "mouse-2, RET: describe this variable")) + +(define-button-type 'info-face + :supertype 'info + 'info-function 'describe-face + 'info-echo (purecopy "mouse-2, RET: describe this face")) + +(define-button-type 'info-symbol + :supertype 'info + 'info-function #'describe-symbol + 'info-echo (purecopy "mouse-2, RET: describe this symbol")) + +(define-button-type 'info-function-def + :supertype 'info + 'info-function (lambda (fun &optional file type) + (or file + (setq file (find-lisp-object-file-name fun type))) + (if (not file) + (message "Unable to find defining file") + (require 'find-func) + (when (eq file 'C-source) + (setq file + (help-C-file-name (indirect-function fun) 'fun))) + ;; Don't use find-function-noselect because it follows + ;; aliases (which fails for built-in functions). + (let ((location + (find-function-search-for-symbol fun type file))) + (pop-to-buffer (car location)) + (run-hooks 'find-function-after-hook) + (if (cdr location) + (goto-char (cdr location)) + (message "Unable to find location in file"))))) + 'info-echo (purecopy "mouse-2, RET: find function's definition")) + +;; Functions + +(defun info-button-action (button) + "Call BUTTON's help function." + (info-do-xref nil + (button-get button 'info-function) + (button-get button 'info-args))) + +(defun info-do-xref (_pos function args) + "Call the help cross-reference function FUNCTION with args ARGS. +Things are set up properly so that the resulting `help-buffer' has +a proper [back] button." + ;; There is a reference at point. Follow it. + (let ((help-xref-following nil)) + (apply + function (if (eq function 'info) + (append args (list (generate-new-buffer-name "*info*")))args)))) + +(defun info-button (match-number type &rest args) + "Make a hyperlink for cross-reference text previously matched. +MATCH-NUMBER is the subexpression of interest in the last matched +regexp. TYPE is the type of button to use. Any remaining arguments are +passed to the button's info-function when it is invoked. +See `info-make-xrefs' Don't forget ARGS." ; -TODO- + ;; Don't mung properties we've added specially in some instances. + (unless (button-at (match-beginning match-number)) + ;; (message "Creating button: %s." args) + (make-text-button (match-beginning match-number) + (match-end match-number) + 'type type 'info-args args))) + +(defconst info-symbol-regexp + (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|" ; Link to var + "\\(function\\|command\\|call\\)\\|" ; Link to function + "\\(face\\)\\|" ; Link to face + "\\(symbol\\|program\\|property\\)\\|" ; Don't link + "\\(source \\(?:code \\)?\\(?:of\\|for\\)\\)\\)" + "[ \t\n]+\\)?" + ;; Note starting with word-syntax character: + "['`‘]\\(\\sw\\(\\sw\\|\\s_\\)+\\|`\\)['’]")) + "Regexp matching info document references to their help references. +The words preceding the quoted symbol can be used in doc strings to +distinguish references to variables, functions and symbols.") + +;;;###autoload +(defun info-make-xrefs (&optional buffer) + "Parse and hyperlink documentation cross-references in the given BUFFER. +Find cross-reference information in a buffer and activate such cross +references for selection with `help-follow'. Cross-references have +the canonical form `...' and the type of reference may be +disambiguated by the preceding word(s) used in +`info-symbol-regexp'. + +Function names are also prefixed by \"M-x\", for example \"M-x +function-name\" or are quoted and prefixed like `M-x +function-name'. + +Also Function names appearing behind the following forms, which +occur, for example, in the Elisp manual: + + -- Special Form: function-name + -- Command: ... + -- Function: ... + -- Macro: ... + +And variables names behind the following text: + + -- User Option: variable-name + -- Variable: ... + +Faces only get cross-referenced if preceded or followed by the +word `face'. Variables without variable documentation do not get +cross-referenced, unless preceded by the word `variable' or +`option'." + (interactive "b") + (when (info-check-docu-p) + (with-current-buffer (or buffer (current-buffer)) + (save-excursion + (goto-char (point-min)) + ;; Skip the header-type info, though it might be useful to parse + ;; it at some stage (e.g. "function in `library'"). + ;; (forward-paragraph) + (with-silent-modifications ;from Stefan + (let (;(stab (syntax-table)) + (case-fold-search t) + (inhibit-read-only t)) + (with-syntax-table emacs-lisp-mode-syntax-table + ;; Quoted symbols + (save-excursion + (while (re-search-forward info-symbol-regexp nil t) + (let* ((data (match-string 8)) + (sym (intern-soft data))) + (if sym + (cond + ((match-string 3) ; `variable' &c + (and (or (boundp sym) ; `variable' doesn't ensure + ; it's actually bound + (get sym 'variable-documentation)) + (info-button 8 'info-variable sym))) + ((match-string 4) ; `function' &c + (and (fboundp sym) ; similarly + (info-button 8 'info-function sym))) + ((match-string 5) ; `face' + (and (facep sym) + (info-button 8 'info-face sym))) + ((match-string 6)) ; nothing for `symbol' + ((match-string 7) + (info-button 8 'info-function-def sym)) + ((cl-some (lambda (x) (funcall (nth 1 x) sym)) + describe-symbol-backends) + (info-button 8 'info-symbol sym))))))) + + ;; (info "(elisp) Eval") + ;; Elisp manual -- Special Form: + ;; -- Command: + ;; -- Function: function-name function + ;; -- Macro: + (save-excursion + (while (re-search-forward + "-- \\(Special Form:\\|Command:\\|Function:\\|Macro:\\) " + nil t) + (looking-at "\\(\\sw\\|\\s_\\)+") + (let ((sym (intern-soft (match-string 0)))) + (if (fboundp sym) + (info-button 0 'info-function sym))))) + + ;; -- User Option: + ;; -- Variable: variable-name + (save-excursion + (while (re-search-forward + "-- \\(User Option:\\|Variable:\\) " + nil t) + (looking-at "\\(\\sw\\|\\s_\\)+") + (let ((sym (intern-soft (match-string 0)))) + (if (boundp sym) + (info-button 0 'info-variable sym))))) + + ;; M-x prefixed functions + (save-excursion + (while (re-search-forward + ;; Assume command name is only word and symbol + ;; characters to get things like `use M-x foo->bar'. + ;; Command required to end with word constituent + ;; to avoid `.' at end of a sentence. + ;; "\\