* lisp/leim/quail/compose.el ("iso-transl"): New input method.

* doc/emacs/basic.texi (Inserting Text):
Mention transient input method "iso-transl".

* lisp/leim/quail/latin-ltx.el: Use same Keywords as in other quail files.

doc/emacs/basic.texi

@@ -145,6 +145,12 @@ the buffer.
   A numeric argument to @kbd{C-q} or @kbd{C-x 8 ...} specifies
 how many copies of the character to insert (@pxref{Arguments}).
 
+  As an alternative to @kbd{C-x 8}, you can select the corresponding
+transient input method by typing @kbd{C-u C-x \ iso-transl @key{RET}},
+then temporarily activating this transient input method by typing
+@kbd{C-x \ [} will insert the same character @t{‘} (@pxref{transient
+input method}).
+
   In addition, in some contexts, if you type a quotation using grave
 accent and apostrophe @kbd{`like this'}, it is converted to a form
 @t{‘like this’} using single quotation marks, even without @kbd{C-x 8}

etc/NEWS

@@ -663,6 +663,13 @@ to the search string.
 ---
 *** New input method 'compose' based on X Multi_key sequences.
 
+---
+*** New input method 'iso-transl' with the same keys as 'C-x 8'.
+After selecting it as a transient input method with 'C-u C-x \
+iso-transl RET', it supports the same key sequences as 'C-x 8',
+so e.g. like 'C-x 8 [' inserts a left single quotation mark,
+'C-x \ [' does the same.
+
 ---
 *** Improved language transliteration in Malayalam input methods.
 Added a new Mozhi scheme.  The inapplicable ITRANS scheme is now

lisp/leim/quail/compose.el

@@ -2922,5 +2922,31 @@ Examples:
  ("_⍵" ?⍹)
  )
 
+;; Quail package `iso-transl' is based on `C-x 8' key sequences.
+;; This input method supports the same key sequences as defined
+;; by the `C-x 8' keymap in iso-transl.el.
+
+(quail-define-package
+ "iso-transl" "UTF-8" "X8" t
+ "Use the same key sequences as in `C-x 8' keymap defined in iso-transl.el.
+Examples:
+ * E -> €   1 / 2 -> ½   ^ 3 -> ³"
+ '(("\t" . quail-completion))
+ t nil nil nil nil nil nil nil nil t)
+
+(eval-when-compile
+  (require 'iso-transl)
+  (defmacro iso-transl--define-rules ()
+    `(quail-define-rules
+      ,@(mapcar (lambda (rule)
+                  (let ((from (car rule))
+                        (to (cdr rule)))
+                    (list from (if (stringp to)
+                                   (vector to)
+                                 to))))
+                iso-transl-char-map))))
+
+(iso-transl--define-rules)
+
 (provide 'compose)
 ;;; compose.el ends here

lisp/leim/quail/latin-ltx.el

@@ -8,7 +8,7 @@
 
 ;; Author: TAKAHASHI Naoto <ntakahas@m17n.org>
 ;;         Dave Love <fx@gnu.org>
-;; Keywords: multilingual, input, Greek, i18n
+;; Keywords: multilingual, input method, i18n
 
 ;; This file is part of GNU Emacs.