(Syntax Table Functions): Add syntax-after.

lispref/syntax.texi

@@ -501,6 +501,18 @@ We use @code{string} to make it easier to see the character returned by
 @code{char-syntax}.
 @end defun
 
+@defun syntax-after pos
+This function returns a description of the syntax of the character in
+the buffer after position @var{pos}, taking account of syntax
+properties as well as the syntax table.
+
+The value is usually a syntax class character; however, if the buffer
+character has parenthesis syntax, the value is a cons cell of the form
+@code{(@var{class} . @var{match})}, where @var{class} is the syntax
+class character and @var{match} is the buffer character's matching
+parenthesis.
+@end defun
+
 @defun set-syntax-table table
 This function makes @var{table} the syntax table for the current buffer.
 It returns @var{table}.