Expand rx definitions inside (not ...)

* lisp/emacs-lisp/rx.el (rx--translate-not):
* test/lisp/emacs-lisp/rx-tests.el (rx-not, rx-def-in-not):
* doc/lispref/searching.texi (Rx Constructs, Extending Rx):

Allow user-defined rx constructs to be expanded inside (not ...)
forms, for better composability (bug#37849).

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/lispref/searching.texi b/doc/lispref/searching.texi
index 5178575a3bb..74b15cfc7fd 100644
--- a/doc/lispref/searching.texi
+++ b/doc/lispref/searching.texi
@@ -1214,7 +1214,7 @@ Corresponding string regexp: @samp{[@dots{}]}
 @item @code{(not @var{charspec})}
 @cindex @code{not} in rx
 Match a character not included in @var{charspec}.  @var{charspec} can
-be an @code{any}, @code{syntax} or @code{category} form, or a
+be an @code{any}, @code{not}, @code{syntax} or @code{category} form, or a
 character class.@*
 Corresponding string regexp: @samp{[^@dots{}]}, @samp{\S@var{code}},
 @samp{\C@var{code}}
@@ -1581,7 +1581,7 @@ when they are used, not when they are defined.
 User-defined forms are allowed wherever arbitrary @code{rx}
 expressions are expected; for example, in the body of a
 @code{zero-or-one} form, but not inside @code{any} or @code{category}
-forms.
+forms.  They are also allowed inside @code{not} forms.
 @end itemize
 
 @defmac rx-define name [arglist] rx-form