(terminal-composition-function): New function.

(terminal-composition-function-table): New variable.
(auto-compose-chars): If running on a terminal, use
terminal-composition-function-table.

1 files changed, 40 insertions, 2 deletions

diff --git a/lisp/composite.el b/lisp/composite.el
index fc973452cec..30010f0f56d 100644
--- a/lisp/composite.el
+++ b/lisp/composite.el
@@ -427,6 +427,41 @@ See also the command `toggle-auto-composition'.")
 
 (put 'save-buffer-state 'lisp-indent-function 1)
 
+(defun terminal-composition-function (pos &optional string)
+  "General composition function used on terminal.
+Non-spacing characters are composed with the preceding spacing
+character.  All non-spacing characters has this function in
+`terminal-composition-function-table'."
+  (let ((from (1- pos))
+        ch)
+    (if string
+        (length string)
+      (setq pos (1+ pos))
+      (while (and (< pos (point-max))
+                  (= (aref char-width-table (char-after pos)) 0))
+        (setq pos (1+ pos)))
+      (if (and (>= from (point-min))
+               (= (aref (symbol-name (get-char-code-property (char-after from)
+                                                             'general-category))
+                        0)
+                  ?L))
+          (compose-region from pos (buffer-substring from pos))
+        (compose-region (1+ from) pos
+                        (concat " " (buffer-substring (1+ from) pos))))
+      pos)))
+
+(defvar terminal-composition-function-table
+  (let ((table (make-char-table nil)))
+    (map-char-table
+     #'(lambda (key val)
+         (if (= val 0) (set-char-table-range table key
+                                             'terminal-composition-function)))
+     char-width-table)
+    table)
+  "Char table of functions for automatic character composition on terminal.
+This is like `composition-function-table' but used when Emacs is running
+on a terminal.")
+
 (defvar auto-compose-current-font nil
   "The current font-object used for characters being composed automatically.")
 
@@ -444,6 +479,9 @@ This function is the default value of `auto-composition-function' (which see)."
             (let ((start pos)
                   (limit (if string (length string) (point-max)))
                   (auto-compose-current-font font-object)
+                  (table (if (display-graphic-p)
+                             composition-function-table
+                           terminal-composition-function-table))
                   ch func newpos)
               (setq limit
                     (or (text-property-any pos limit 'auto-composed t string)
@@ -455,7 +493,7 @@ This function is the default value of `auto-composition-function' (which see)."
                             (setq ch (aref string pos))
                             (if (= ch ?\n)
                                 (throw 'tag (1+ pos)))
-                            (setq func (aref composition-function-table ch))
+                            (setq func (aref table ch))
                             (if (and (functionp func)
                                      (setq newpos (funcall func pos string))
                                      (> newpos pos))
@@ -465,7 +503,7 @@ This function is the default value of `auto-composition-function' (which see)."
                           (setq ch (char-after pos))
                           (if (= ch ?\n)
                               (throw 'tag (1+ pos)))
-                          (setq func (aref composition-function-table ch))
+                          (setq func (aref table ch))
                           (if (and (functionp func)
                                    (setq newpos (funcall func pos string))
                                    (> newpos pos))