Small doc related to new completion functions

* doc/lispref/minibuf.texi (Programmed Completion):
Mention completion-table-with-cache.

* lisp/minibuffer.el (completion-table-dynamic)
(completion-table-with-cache): Doc fixes.

* etc/NEWS: Related markup.  Unrelated copyedit.

doc/lispref/ChangeLog

@@ -1,3 +1,8 @@
+2014-02-27  Glenn Morris  <rgm@gnu.org>
+
+	* minibuf.texi (Programmed Completion):
+	Mention completion-table-with-cache.
+
 2014-02-25  Glenn Morris  <rgm@gnu.org>
 
 	* display.texi (Window Systems):

doc/lispref/minibuf.texi

@@ -1814,6 +1814,13 @@ possible completions of it.  You can think of
 and the interface for programmed completion functions.
 @end defun
 
+@defun completion-table-with-cache function &optional ignore-case
+This is a wrapper for @code{completion-table-dynamic} that saves the
+last argument-result pair.  This means that multiple lookups with the
+same argument only need to call @var{function} once.  This can be useful
+when a slow operation is involved, such as calling an external process.
+@end defun
+
 @node Completion in Buffers
 @subsection Completion in Ordinary Buffers
 @cindex inline completion

etc/NEWS

@@ -1183,15 +1183,17 @@ Either use `completion-all-completions', which returns highlighted
 strings (including for partial or substring completion), or call
 `completion-hilit-commonality' to add the highlight.
 
++++
 *** New function `completion-table-with-cache' is a wrapper for
 `completion-table-dynamic' that caches the result of the last lookup.
 
++++
 *** New function `completion-table-merge' to combine several
 completion tables by merging their completions.
 
 ** New minor modes `prettify-symbols-mode' and `global-prettify-symbols-mode'
-let you enable symbol prettification (replacing a string like "lambda" with
-the Greek lambda character).
+display specified symbols as composed characters.  E.g., in Emacs Lisp mode,
+this replaces the string "lambda" with the Greek lambda character.
 
 ** Terminal changes
 

lisp/ChangeLog

@@ -1,5 +1,8 @@
 2014-02-27  Glenn Morris  <rgm@gnu.org>
 
+	* minibuffer.el (completion-table-dynamic)
+	(completion-table-with-cache): Doc fixes.
+
 	* emacs-lisp/crm.el (crm-default-separator, crm-separator)
 	(completing-read-multiple): Doc fixes.
 

lisp/minibuffer.el

@@ -179,7 +179,9 @@ FUN will be called in the buffer from which the minibuffer was entered.
 
 The result of the `completion-table-dynamic' form is a function
 that can be used as the COLLECTION argument to `try-completion' and
-`all-completions'.  See Info node `(elisp)Programmed Completion'."
+`all-completions'.  See Info node `(elisp)Programmed Completion'.
+
+See also the related function `completion-table-with-cache'."
   (lambda (string pred action)
     (if (or (eq (car-safe action) 'boundaries) (eq action 'metadata))
         ;; `fun' is not supposed to return another function but a plain old
@@ -191,13 +193,15 @@ that can be used as the COLLECTION argument to `try-completion' and
         (complete-with-action action (funcall fun string) string pred)))))
 
 (defun completion-table-with-cache (fun &optional ignore-case)
-  "Create dynamic completion table from FUN, with cache.
-This wraps `completion-table-dynamic', but saves the last
+  "Create dynamic completion table from function FUN, with cache.
+This is a wrapper for `completion-table-dynamic' that saves the last
 argument-result pair from FUN, so that several lookups with the
 same argument (or with an argument that starts with the first one)
-only need to call FUN once.  Most useful when FUN performs a relatively
-slow operation, such as calling an external process (see Bug#11906).
+only need to call FUN once.  This can be useful when FUN performs a
+relatively slow operation, such as calling an external process.
+
 When IGNORE-CASE is non-nil, FUN is expected to be case-insensitive."
+  ;; See eg bug#11906.
   (let* (last-arg last-result
          (new-fun
           (lambda (arg)