@c "chapters/attributes.texi"
@c $Id: attributes.texi,v 1.1 2008/10/07 03:22:17 fang Exp $

@node Attributes
@chapter Attributes
@cindex attributes

Instance attributes are a way of communicating to other tools that
something is @emph{special} about a particular instance.  
The language provides some attributes for the standard meta-types.  

@menu
* Bool Attributes::
* Channel Attributes::
* Process Attributes::
@end menu

@c - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@node Bool Attributes
@section Bool Attributes

Thus far all attributes on bools (nodes) are boolean valued.  
The default un-attributed node assumes default values for 
all known attributes.  
Boolean attributes are contagious in that once they are set 
to non-default values, they cannot be unset.
Non-default values also propagate bottom-up through ports 
in the instance hierarchy.  
(They cannot propagate top-down, for that would violate modularity.)
Furthermore, when connecting nodes, the non-default value always
dominates (spreads contagiously).  
Keep this in mind when deciding at which level of hierarchy to
attach attributes.  

@include attrib/bool-iscomb.texi
@include attrib/bool-autokeeper.texi

@c - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@node Channel Attributes
@section Channel Attributes

TODO: add some attributes

@c - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@node Process Attributes
@section Process Attributes

TODO: add some attributes

