Built-in simple datatypes

Schemas have a number of built-in simple datatypes:

• Numerical: integer (also positive or negative), double, float, ...
• Logical: boolean
• Time: duration, time instant, date, month,...
• String
• XML datatypes: ID, IDREFS, Notations
• URI-s

eg, we could have said:

  <element name="Room" type="positiveInteger"/>