If non-zero, @code{readline} will call indirectly through this pointer
to update the display with the current contents of the editing buffer.
By default, it is set to @code{rl_redisplay}, the default @code{readline}
If non-zero, @code{readline} will call indirectly through this pointer
to update the display with the current contents of the editing buffer.
By default, it is set to @code{rl_redisplay}, the default @code{readline}