Function: help-make-xrefs
help-make-xrefs is an autoloaded, interactive and byte-compiled
function defined in help-mode.el.gz.
Signature
(help-make-xrefs &optional BUFFER)
Documentation
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-symbol. Cross-references have
the canonical form ... and the type of reference may be
disambiguated by the preceding word(s) used in
help-xref-symbol-regexp. 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.
If the variable help-xref-mule-regexp is non-nil, find also
cross-reference information related to multilingual environment
(e.g., coding-systems). This variable is also used to disambiguate
the type of reference as the same way as help-xref-symbol-regexp.
A special reference back is made to return back through a stack of
help buffers. Variable help-back-label specifies the text for
that.
Key Bindings
Source Code
;; Defined in /usr/src/emacs/lisp/help-mode.el.gz
;;;###autoload
(defun help-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-symbol'. Cross-references have
the canonical form `...' and the type of reference may be
disambiguated by the preceding word(s) used in
`help-xref-symbol-regexp'. 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'.
If the variable `help-xref-mule-regexp' is non-nil, find also
cross-reference information related to multilingual environment
\(e.g., coding-systems). This variable is also used to disambiguate
the type of reference as the same way as `help-xref-symbol-regexp'.
A special reference `back' is made to return back through a stack of
help buffers. Variable `help-back-label' specifies the text for
that."
(interactive "b")
(with-current-buffer (or buffer (current-buffer))
(save-excursion
(goto-char (point-min))
;; Skip the first bit, which has already been buttonized.
(forward-paragraph)
(let ((old-modified (buffer-modified-p)))
(let ((stab (syntax-table))
(case-fold-search t)
(inhibit-read-only t))
(set-syntax-table help-mode-syntax-table)
;; The following should probably be abstracted out.
(unwind-protect
(progn
;; Info references
(save-excursion
(while (re-search-forward help-xref-info-regexp nil t)
(let ((data (match-string 2)))
(save-match-data
(unless (string-match "^([^)]+)" data)
(setq data (concat "(emacs)" data)))
(setq data ;; possible newlines if para filled
(replace-regexp-in-string "[ \t\n]+" " " data t t)))
(help-xref-button 2 'help-info data))))
;; Man references
(save-excursion
(while (re-search-forward help-xref-man-regexp nil t)
(help-xref-button 1 'help-man (match-string 1))))
;; Customization groups.
(save-excursion
(while (re-search-forward
help-xref-customization-group-regexp nil t)
(help-xref-button 1 'help-customization-group
(intern (match-string 1)))))
;; URLs
(save-excursion
(while (re-search-forward help-xref-url-regexp nil t)
(let ((data (match-string 1)))
(help-xref-button 1 'help-url data))))
;; Mule related keywords. Do this before trying
;; `help-xref-symbol-regexp' because some of Mule
;; keywords have variable or function definitions.
(if help-xref-mule-regexp
(save-excursion
(while (re-search-forward help-xref-mule-regexp nil t)
(let* ((data (match-string 7))
(sym (intern-soft data)))
(cond
((match-string 3) ; coding system
(and sym (coding-system-p sym)
(help-xref-button 6 'help-coding-system sym)))
((match-string 4) ; input method
(and (assoc data input-method-alist)
(help-xref-button 7 'help-input-method data)))
((or (match-string 5) (match-string 6)) ; charset
(and sym (charsetp sym)
(help-xref-button 7 'help-character-set sym)))
((assoc data input-method-alist)
(help-xref-button 7 'help-input-method data))
((and sym (coding-system-p sym))
(help-xref-button 7 'help-coding-system sym))
((and sym (charsetp sym))
(help-xref-button 7 'help-character-set sym)))))))
;; Quoted symbols
(save-excursion
(while (re-search-forward help-xref-symbol-regexp nil t)
(when-let ((sym (intern-soft (match-string 9))))
(if (match-string 8)
(delete-region (match-beginning 8)
(match-end 8))
(cond
((match-string 3) ; `variable' &c
(and (or (boundp sym) ; `variable' doesn't ensure
; it's actually bound
(get sym 'variable-documentation))
(help-xref-button 9 'help-variable sym)))
((match-string 4) ; `function' &c
(and (fboundp sym) ; similarly
(help-xref-button 9 'help-function sym)))
((match-string 5) ; `face'
(and (facep sym)
(help-xref-button 9 'help-face sym)))
((match-string 6)) ; nothing for `symbol'
((match-string 7)
(help-xref-button 9 'help-function-def sym))
((cl-some (lambda (x) (funcall (nth 1 x) sym))
describe-symbol-backends)
(help-xref-button 9 'help-symbol sym)))))))
;; An obvious case of a key substitution:
(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.
"\\<M-x\\s-+\\(\\sw\\(\\sw\\|\\s_\\)*\\sw\\)" nil t)
(let ((sym (intern-soft (match-string 1))))
(if (fboundp sym)
(help-xref-button 1 'help-function sym))))))
(set-syntax-table stab))
;; Delete extraneous newlines at the end of the docstring
(goto-char (point-max))
(while (and (not (bobp)) (bolp))
(delete-char -1))
(insert "\n")
(help-xref--navigation-buttons))
(set-buffer-modified-p old-modified)))))