Added notes for call with Harish to better understand the Typesystem

typesystem/doc/notes.MD

+## Call with Harish on the initial typesystem naming conventions and intentions
+
+### Structs are like C structs - they don't have an identity
+- no independent lifecycle
+- like a bag of properties
+- like in hive, also
+
+### Classes are classes
+- like any OO class
+- have identity
+- can have inheritence
+- can contain structs
+- don't necessarily need to use a struct inside the class to define props
+- can also define props using AttributeDefinition using the basic data types
+- classes are immutable once created
+
+### On search interface:
+- can search for all instances of a class
+- classes could become tables in a relational system, for instance
+	- also databases, columns, etc.
+
+### Traits is similar to scala - traits more like decorators (?)
+- traits get applied to instances - not classes
+	- this satisfies the classification mechanism (ish)
+- can have a class instance have any number of traits
+- e.g. security clearance - any Person class could have it; so we add it as a mixin to the Person class
+	- security clearance trait has a level attribute
+	- traits are labels
+	- each label can have its own attribute
+- reason for doing this is:
+	- modeled security clearance trait
+	- want to prescribe it to other things, too
+	- can now search for anything that has security clearance level = 1, for instance
+
+### On Instances:
+- class, trait, struct all have bags of attributes
+- can get name of type associated with attribute
+- can get or set the attribute in that bag for each instance
+
+### On Classification:
+- create column as a class
+- create a trait to classify as "PHI"
+- would create the instance of the column with the PHI trait
+- apply traits to instances
+- CAN'T apply traits to class
+
+### Other useful information
+
+HierarchicalClassType - base type for ClassType and TraitType
+Instances created from Definitions
+
+Every instance is referenceable - i.e. something can point to it in the graph db
+MetadataService may not be used longterm - it is currently used for bootstrapping the repo & type system
+
+Id class - represents the Id of an instance
+
+When the web service receives an object graph, the ObjectGraphWalker is used to update things
+	- DiscoverInstances is used to discover the instances in the object graph received by the web service
+	
+MapIds assigns new ids to the discovered instances in the object graph
+
+Anything under the storage package is not part of the public interface
\ No newline at end of file