<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

<!--
  Brian A. Malloy,
  Department of Computer Science, Clemson University
-->

  <xsd:annotation>
    <xsd:documentation xml:lang="en">
     Class Diagram schema for Assignment #4.
    </xsd:documentation>
  </xsd:annotation>

  <xsd:element name="ClassDiagram" type="ClassDiagramType"/>

  <xsd:complexType name="ClassDiagramType">
    <xsd:sequence>
      <xsd:element name="entry" 
                   minOccurs="0" maxOccurs="unbounded"
                   type="Entry"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:complexType name="Entry">
    <xsd:sequence>
      <xsd:element name="classname" type="xsd:string"/>
      <xsd:element name="edge" 
                   minOccurs="0" maxOccurs="unbounded"
                   type="Edge"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:complexType name="Edge">
    <xsd:sequence>
      <xsd:element name="type" type="EdgeType"/>
      <xsd:element name="from" type="xsd:string"/>
      <xsd:element name="to"   type="xsd:string"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:simpleType name="EdgeType">
    <xsd:restriction base="xsd:string">
      <xsd:enumeration value="Inheritance"/>
      <xsd:enumeration value="Association"/>
      <xsd:enumeration value="Composition"/>
      <xsd:enumeration value="Dependence"/>
    </xsd:restriction>
  </xsd:simpleType>

</xsd:schema>