Communications functions
------------------------

Most of the time, if you want to send a message to an object or group
of objects, the correct function to use is tell().  tell(ob, str) is
the correct way to send the message "str" to the object "ob" (and just
that object; it isn't propagated to the objects inventory or
environment or anything).  If a third argument is passed, it is used
as the message type.  It is also possible to use an array of objects
as the first argument.  The message is then sent to all the objects in
the array.  For example, tell(users(), "Hi there!") sends the message
to everyone who is logged in.

[Note: messages can be sent either to user objects or body objects; body
 objects simply forward the message to their user.  bodies() could be
 used in the above, and the effect would be the same.]

For convenience, there is also a tell_user(name, msg), which tells the
user "name" (if any) the message.  tell_user("yourname", ...) can be
handy for debugging.

There also exist non-private messages, which in addition to sending
the message to a particular object, also automatically propagate to
other objects which are able to see the event.  The most useful of
these is tell_environment(ob, msg), which also sends the message to
everything in the environment of ob (if any).  The message will also
propagate up and down through the object hierarchy, unless blocked by
some non-transparent object.  tell_from_inside() and tell_from_outside()
are lower level versions; tell_from_inside() sends the message to a
particular object, propagating up and down, which tell_from_outside()
propagates down only.

tell_from_inside(), tell_from_outside(), and tell_environment() also
support a fourth argument containing an array of objects which should
not hear the message.

[compatibility notes]

For those used to the old efuns, the following may be helpful:

tell_object() is for the most part replaced by tell().

tell_room() usually becomes tell_from_outside() (with the exception that
    the extremely common construct 'tell_room(environment(ob), ...)'
    should use tell_environment(ob, ...))

say() also becomes tell_environment(this_object(), ...) in most cases,
    although when done from an non-living object it becomes
    tell_environment(this_body(), ...)

write() and printf() still work; though they are simul'ed to use
    tell(this_user(), ...), which works exactly the way the old efuns
    did, except that wrapping and color translation are done.

-Beek