+;; If the entire line cannot fit in the echo area, the symbol name may be
+;; truncated or eliminated entirely from the output to make room for the
+;; description.
+(defun eldoc-docstring-format-sym-doc (prefix doc &optional face)
+ (when (symbolp prefix)
+ (setq prefix (concat (propertize (symbol-name prefix) 'face face) ": ")))
+ (let* ((ea-multi eldoc-echo-area-use-multiline-p)
+ ;; Subtract 1 from window width since emacs will not write
+ ;; any chars to the last column, or in later versions, will
+ ;; cause a wraparound and resize of the echo area.
+ (ea-width (1- (window-width (minibuffer-window))))
+ (strip (- (+ (length prefix) (length doc)) ea-width)))
+ (cond ((or (<= strip 0)
+ (eq ea-multi t)
+ (and ea-multi (> (length doc) ea-width)))
+ (concat prefix doc))
+ ((> (length doc) ea-width)
+ (substring (format "%s" doc) 0 ea-width))
+ ((>= strip (string-match-p ":? *\\'" prefix))
+ doc)
+ (t
+ ;; Show the end of the partial symbol name, rather
+ ;; than the beginning, since the former is more likely
+ ;; to be unique given package namespace conventions.
+ (concat (substring prefix strip) doc)))))
+