metastructures 1999technoteacher, inc. what are groves? peter newcomb
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Metastructures 1999 TechnoTeacher, Inc.
What are
GROVES?
Peter Newcomb
Metastructures 1999 TechnoTeacher, Inc.
What is a GROVE?
• A “grove” represents a structured collection of information objects.– a document– a database– a graphic– ...
Metastructures 1999 TechnoTeacher, Inc.
What is a GROVE made of?
• A grove consists of a set of nodes.
• Each “node” represents an addressable information object.
Metastructures 1999 TechnoTeacher, Inc.
What’s in a NODE?
• A node consists of a set of named values.
• Each named value is called a “property assignment”.
Metastructures 1999 TechnoTeacher, Inc.
What’s a PROPERTY?
• A “property” is a named characteristic of an information object.
• Each property has a specific datatype.
Metastructures 1999 TechnoTeacher, Inc.
What DATATYPES canproperties have?
• Primitive datatypes:– character, string, integer, …– string list, integer list, …
• Nodal datatypes:– node, node list, named node list
Metastructures 1999 TechnoTeacher, Inc.
What’s a NODAL DATATYPE?
• The value assigned to a “nodal property” is a node or list of nodes.
• Nodal properties represent relationships between information objects.
Metastructures 1999 TechnoTeacher, Inc.
What kinds of NODAL RELATIONSHIPS are there?
• Subordinate (SUBNODE)– forms hierarchies (trees) of nodes– each grove is a single SUBNODE tree
Metastructures 1999 TechnoTeacher, Inc.
What kinds of NODAL RELATIONSHIPS are there?
• Internal reference (IREFNODE)– creates cross-references within a
single grove
Metastructures 1999 TechnoTeacher, Inc.
What kinds of NODAL RELATIONSHIPS are there?
• Unrestricted reference (UREFNODE)– creates cross-references within or
between groves– a set of UREFNODE-connected groves
is called a “hypergrove”.
Metastructures 1999 TechnoTeacher, Inc.
How do I know what PROPERTIES a node will have?
• Each node is an instance of a named class of nodes.
• A “node class” defines a set of properties.
Metastructures 1999 TechnoTeacher, Inc.
How do I know what NODE CLASSES a grove will have?
• The set of node classes that may be found in a grove is defined by the grove’s “property set”.
• A property set is a schema for groves.
Metastructures 1999 TechnoTeacher, Inc.
What does a PROPERTY SET represent?
• A property set represents an abstract data model for a specific type of structured information.
• A property set is expressed as an SGML or XML document.
Metastructures 1999 TechnoTeacher, Inc.
What is the GROVE model not?
• A programming interface (API)
• A data format, binary or otherwise
Metastructures 1999 TechnoTeacher, Inc.
What is the GROVE model?
• An abstract generic data model
• A mechanism for defining specific data models
Metastructures 1999 TechnoTeacher, Inc.
How do I use the GROVE model?
• Define an API to the generic data model– How do I build a grove?
– How do I get the value of a property?
– How do I access list values?
– …
Metastructures 1999 TechnoTeacher, Inc.
How do I use the GROVE model?
• Define an API to a specific grove type– Balise
– XML DOM
Metastructures 1999 TechnoTeacher, Inc.
How do I use the GROVE model?
• Implement the API– generically, for any grove type
• GroveMinder
– specifically, for one grove type• Jade (James Clark’s DSSSL engine)
• Any XML DOM implementation