* doc/lispref/minibuf.texi (Basic Completion): Be a bit more precise about the

valid kinds of completion tables.
(Programmed Completion): Remove obsolete text about lambda expressions
not being valid completion tables.

2 files changed, 20 insertions, 21 deletions

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index 26bb5888df5..440159a9a58 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,3 +1,10 @@
+2011-03-21  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * minibuf.texi (Basic Completion): Be a bit more precise about the
+        valid kinds of completion tables.
+        (Programmed Completion): Remove obsolete text about lambda expressions
+        not being valid completion tables.
+
 2011-03-19  Chong Yidong  <cyd@stupidchicken.com>
 
         * positions.texi (Excursions): Explain the "save-excursion
diff --git a/doc/lispref/minibuf.texi b/doc/lispref/minibuf.texi
index 0d907ea6532..9b09a304bd0 100644
--- a/doc/lispref/minibuf.texi
+++ b/doc/lispref/minibuf.texi
@@ -647,9 +647,9 @@ higher-level completion features that do use the minibuffer.
 @defun try-completion string collection &optional predicate
 This function returns the longest common substring of all possible
 completions of @var{string} in @var{collection}.  The value of
-@var{collection} must be a list of strings or symbols, an alist, an
-obarray, a hash table, or a completion function (@pxref{Programmed
-Completion}).
+@var{collection} must be a list of strings, an alist whose keys are
+strings or symbols, an obarray, a hash table, or a completion function
+(@pxref{Programmed Completion}).
 
 Completion compares @var{string} against each of the permissible
 completions specified by @var{collection}.  If no permissible
@@ -660,11 +660,11 @@ to all possible matching completions.
 
 If @var{collection} is an alist (@pxref{Association Lists}), the
 permissible completions are the elements of the alist that are either
-strings, symbols, or conses whose @sc{car} is a string or symbol.
+strings, or conses whose @sc{car} is a string or symbol.
 Symbols are converted to strings using @code{symbol-name}.  Other
 elements of the alist are ignored. (Remember that in Emacs Lisp, the
 elements of alists do not @emph{have} to be conses.)  In particular, a
-list of strings or symbols is allowed, even though we usually do not
+list of strings is allowed, even though we usually do not
 think of such lists as alists.
 
 @cindex obarray in completion
@@ -680,7 +680,7 @@ Also, you cannot intern a given symbol in more than one obarray.
 If @var{collection} is a hash table, then the keys that are strings
 are the possible completions.  Other keys are ignored.
 
-You can also use a symbol that is a function as @var{collection}.
+You can also use a function as @var{collection}.
 Then the function is solely responsible for performing completion;
 @code{try-completion} returns whatever this function returns.  The
 function is called with three arguments: @var{string}, @var{predicate}
@@ -1634,12 +1634,12 @@ which performs completion according to the rules used in Emacs 21; and
 @subsection Programmed Completion
 @cindex programmed completion
 
-  Sometimes it is not possible to create an alist or an obarray
-containing all the intended possible completions.  In such a case, you
-can supply your own function to compute the completion of a given
-string.  This is called @dfn{programmed completion}.  Emacs uses
-programmed completion when completing file names (@pxref{File Name
-Completion}), among many other cases.
+  Sometimes it is not possible or convenient to create an alist or
+an obarray containing all the intended possible completions ahead
+of time.  In such a case, you can supply your own function to compute
+the completion of a given string.  This is called @dfn{programmed
+completion}.  Emacs uses programmed completion when completing file
+names (@pxref{File Name Completion}), among many other cases.
 
   To use this feature, pass a function as the @var{collection}
 argument to @code{completing-read}.  The function
@@ -1667,7 +1667,7 @@ specifies which method to run.
 @end itemize
 
   There are currently four methods, i.e. four flag values, one for
-  each of the four different basic operations:
+each of the four different basic operations:
 
 @itemize @bullet
 @item
@@ -1698,14 +1698,6 @@ in the string to complete, and END is the position of the end boundary
 in SUFFIX.
 @end itemize
 
-  It would be consistent and clean for completion functions to allow
-lambda expressions (lists that are functions) as well as function
-symbols as @var{collection}, but this is impossible.  Lists as
-completion tables already have other meanings, and it would be
-unreliable to treat one differently just because it is also a possible
-function.  So you must arrange for any function you wish to use for
-completion to be encapsulated in a symbol.
-
 @defun completion-table-dynamic function
 This function is a convenient way to write a function that can act as
 programmed completion function.  The argument @var{function} should be