Implement bidi-sensitive movement with arrow keys.

 src/bidi.c (bidi_paragraph_init): Don't leave alone garbage values
 of bidi_it->paragraph_dir.  Call bidi_initialize if needed.
 src/xdisp.c (Fcurrent_bidi_paragraph_direction): New function.
 (syms_of_xdisp): Defsubr it.
 src/cmds.c (Fforward_char, Fbackward_char): Doc fix.
 src/subr.el (right-arrow-command, left-arrow-command): New functions.
 src/bindings.el (global-map): Bind them to right and left arrow keys.
 etc/NEWS: Mention current-bidi-paragraph-direction

1 files changed, 12 insertions, 4 deletions

diff --git a/src/cmds.c b/src/cmds.c
index 5d450fe9a13..b8a65324e9f 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -57,8 +57,12 @@ DEFUN ("forward-point", Fforward_point, Sforward_point, 1, 1, 0,
 }
 
 DEFUN ("forward-char", Fforward_char, Sforward_char, 0, 1, "^p",
-       doc: /* Move point right N characters (left if N is negative).
-On reaching end of buffer, stop and signal error.  */)
+       doc: /* Move point N characters forward (backward if N is negative).
+On reaching end or beginning of buffer, stop and signal error.
+
+Depending on the bidirectional context, the movement may be to the
+right or to the left on the screen.  This is in contrast with
+\\[right-arrow-command], which see.  */)
      (n)
      Lisp_Object n;
 {
@@ -93,8 +97,12 @@ On reaching end of buffer, stop and signal error.  */)
 }
 
 DEFUN ("backward-char", Fbackward_char, Sbackward_char, 0, 1, "^p",
-       doc: /* Move point left N characters (right if N is negative).
-On attempt to pass beginning or end of buffer, stop and signal error.  */)
+       doc: /* Move point N characters backward (forward if N is negative).
+On attempt to pass beginning or end of buffer, stop and signal error.
+
+Depending on the bidirectional context, the movement may be to the
+right or to the left on the screen.  This is in contrast with
+\\[left-arrow-command], which see.  */)
      (n)
      Lisp_Object n;
 {