Re: Improved help from minibuffer prompts

[Juanma Barranquero <jmbarranquero@wke.es>]

On 30 Apr 2004 12:08:47 +0200
storm@cua.dk (Kim F. Storm) wrote:

> I have applied your patch locally; I'll use it for a while before
> I'll make a judgement.

Please, try this one instead.  It's a bit less elegant because of the
support for CL-style optional arguments, but it works in all tests cases
I've tried.

> But initially, I like it.

Glad to hear.

                                                                Juanma

--- help-fns.el.orig	2004-04-30 15:31:10.000000000 +0200
+++ help-fns.el	2004-04-30 15:28:47.000000000 +0200
@@ -131,4 +131,33 @@
 ;; Functions
 
+(defun help-highlight-arguments (fun &rest args)
+  (save-excursion
+    (goto-char (point-min))
+    (let* ((case-fold-search nil)
+           (next (and (not args)
+                      (re-search-forward (concat "(" (symbol-name fun)) nil t))))
+      (save-restriction
+        (narrow-to-region (point) (re-search-forward ")\n" nil t))
+        (goto-char (point-min))
+        ;; Make a list of all arguments
+        (while next
+          (if (not (re-search-forward " \\((?\\)\\([^ &\)\.]+\\)" nil t))
+              (setq next nil)
+            (setq args (cons (match-string 2) args))
+            (unless (string= (match-string 1) "")
+              ;; A pesky CL-style optional argument with default value,
+              ;; so let's skip over it
+              (search-backward "(")
+              (goto-char (scan-sexps (point) 1))))))
+      ;; Highlight all found arguments anywhere in the *Help* buffer
+      (while args
+        (let* ((arg (car args))
+               (solo (concat "\\<\\(" arg "\\)e?s?\\>"))
+               (high (propertize arg 'face 'font-lock-variable-name-face)))
+          (setq args (cdr args))
+          (goto-char (point-min))
+          (while (re-search-forward solo nil t)
+            (replace-match high nil t nil 1)))))))
+
 ;;;###autoload
 (defun describe-function (function)
@@ -156,4 +185,6 @@
 	(print-help-return-message)
 	(with-current-buffer standard-output
+          ;; highlight argument names
+          (help-highlight-arguments function)
 	  ;; Return the text we displayed.
 	  (buffer-string))))))