# target.icn:  An object to represent a location to which links
#   may point, for webstyler.icn.
#--

$define  TARGET_REVISION    "$Revision: 1.2 $"
$define  TARGET_DATE        "$Date: 1996/10/10 18:14:39 $"

#================================================================
# Class Target: Each instance represents a location to which a
# link can point: a topic, plus an optional anchor-name within
# that topic.  This object was added for external version 1.03,
# before which anchors within short names were not supported.
#----------------------------------------------------------------
  record targetTag (        # State for a Target object
    topic,          # A Topic object
    anchor )        # An anchor including the pound sign, or &null
#----------------------------------------------------------------
# INVARIANTS
#----------------------------------------------------------------
# .topic == a Topic object
# .anchor ==
#   if this target represents a specific anchor ->
#     a string consisting of "#" followed by the anchor name
#   else -> &null
#----------------------------------------------------------------
# METHODS
#----------------------------------------------------------------
# Target_New ( topic, anchor )
#   [ if the arguments satisfy the corresponding invariants ->
#       returns a new Topic object representing those values
#   ]
#--
# Target_Topic ( self )
#   [ returns self.topic
#   ]
#--
# Target_Anchor ( self )
#   [ if self.anchor is not &null ->
#       returns self.anchor
#   | else -> fails
#   ]
#----------------------------------------------------------------



# - - -   T a r g e t _ N e w   - - -

procedure Target_New ( topic, anchor )
  local target

  target         :=  targetTag ( );
  target.topic   :=  topic;
  target.anchor  :=  anchor;

  return target;
end


# - - -   T a r g e t _ T o p i c   - - -

procedure Target_Topic ( self )
  return self.topic;
end


# - - -   T a r g e t _ A n c h o r   - - -

procedure Target_Anchor ( self )
  return  \ self.anchor;    # Fails if .anchor is &null
end