Revert "Allow zero-argument rx `or' and `seq' forms"

This reverts commit b552fc05c231ca6800330a318d3a74ddd0f5a13c.
It caused a bootstrapping failure which I have yet to resolve - sorry.

1 files changed, 5 insertions, 8 deletions

diff --git a/lisp/emacs-lisp/rx.el b/lisp/emacs-lisp/rx.el
index 9478bd3bbdb..9d9028d87d5 100644
--- a/lisp/emacs-lisp/rx.el
+++ b/lisp/emacs-lisp/rx.el
@@ -110,11 +110,11 @@
 ;; FIXME: support macros.
 
 (defvar rx-constituents              ;Not `const' because some modes extend it.
-  '((and                . (rx-and 0 nil))
+  '((and                . (rx-and 1 nil))
     (seq                . and)          ; SRE
     (:                  . and)          ; SRE
     (sequence           . and)          ; sregex
-    (or                 . (rx-or 0 nil))
+    (or                 . (rx-or 1 nil))
     (|                  . or)           ; SRE
     (not-newline        . ".")
     (nonl               . not-newline)  ; SRE
@@ -390,11 +390,9 @@ FORM is of the form `(and FORM1 ...)'."
   "Parse and produce code from FORM, which is `(or FORM1 ...)'."
   (rx-check form)
   (rx-group-if
-   (cond
-    ((null (cdr form)) regexp-unmatchable)
-    ((cl-every #'stringp (cdr form))
+   (if (memq nil (mapcar 'stringp (cdr form)))
+       (mapconcat (lambda (x) (rx-form x '|)) (cdr form) "\\|")
      (regexp-opt (cdr form) nil t))
-    (t (mapconcat (lambda (x) (rx-form x '|)) (cdr form) "\\|")))
    (and (memq rx-parent '(: * t)) rx-parent)))
 
 
@@ -1123,7 +1121,6 @@ CHAR
 `(seq SEXP1 SEXP2 ...)'
 `(sequence SEXP1 SEXP2 ...)'
      matches what SEXP1 matches, followed by what SEXP2 matches, etc.
-     Without arguments, matches the empty string.
 
 `(submatch SEXP1 SEXP2 ...)'
 `(group SEXP1 SEXP2 ...)'
@@ -1139,7 +1136,7 @@ CHAR
 `(| SEXP1 SEXP2 ...)'
      matches anything that matches SEXP1 or SEXP2, etc.  If all
      args are strings, use `regexp-opt' to optimize the resulting
-     regular expression.  Without arguments, never matches anything.
+     regular expression.
 
 `(minimal-match SEXP)'
      produce a non-greedy regexp for SEXP.  Normally, regexps matching