Update Functions chapter of Lisp manual; document closures.

* doc/emacs/functions.texi (What Is a Function): Add closures.  Mention
"return value" terminology.  Add xref for command-execute.  Remove
unused "keystroke command" terminology.
(Lambda Expressions): Give a different example than in the
following subsection.  Add xref to Anonymous Functions.
(Function Documentation): Remove gratuitous markup.
(Function Names): Move introductory text to `What Is a Function'.
(Defining Functions): Fix defun argument spec.
(Anonymous Functions): Document lambda macro explicitly.  Mention
effects on lexical binding.
(Function Cells): Downplay direct usage of fset.
(Closures): New node.
(Inline Functions): Remove "open-code" terminology.
(Declaring Functions): Minor tweak; .m is not C code.

* doc/emacs/variables.texi (Variables): Don't refer to "global value".
(Local Variables, Void Variables): Copyedits.
(Lexical Binding): Minor clarification of example.
(File Local Variables): Mention :safe and :risky defcustom args.
(Lexical Binding): Add xref to Closures node.

1 files changed, 1 insertions, 0 deletions

diff --git a/doc/lispref/vol1.texi b/doc/lispref/vol1.texi
index 3a2f4723b05..4a48536f5f3 100644
--- a/doc/lispref/vol1.texi
+++ b/doc/lispref/vol1.texi
@@ -478,6 +478,7 @@ Functions
 * Anonymous Functions::     Lambda expressions are functions with no names.
 * Function Cells::          Accessing or setting the function definition
                               of a symbol.
+* Closures::                Functions that enclose a lexical environment.
 * Obsolete Functions::      Declaring functions obsolete.
 * Inline Functions::        Defining functions that the compiler
                               will open code.