Add XSD to check generated XML compliancy

src/xml_marshaller/doc/xml_marshaller.xsd

+<?xml version="1.0" encoding="utf-8"?>
+<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="unqualified"
+           attributeFormDefault="unqualified">
+
+
+  <!-- SimpleType Declarations -->
+
+  <xs:simpleType name="Complex">
+    <xs:annotation>
+      <xs:documentation>
+        Two float with space as separator
+      </xs:documentation>
+    </xs:annotation>
+    <xs:restriction base="xs:string">
+      <xs:pattern value="\d+\.\d*\s\d+\.\d*"/>
+    </xs:restriction>
+  </xs:simpleType>
+
+  <xs:simpleType name="None">
+    <xs:annotation>
+      <xs:documentation>
+        Empty element
+      </xs:documentation>
+    </xs:annotation>
+    <xs:restriction base="xs:string">
+      <xs:maxLength value="0"/>
+    </xs:restriction>
+  </xs:simpleType>
+
+  <!-- ComplexType declarations -->
+
+  <xs:complexType name="Reference">
+    <xs:annotation>
+      <xs:documentation>
+        Its attribute id should refer to foreign key
+      </xs:documentation>
+    </xs:annotation>
+    <xs:attribute name="id" type="xs:string"/>
+  </xs:complexType>
+
+  <xs:complexType name="Object">
+    <xs:annotation>
+      <xs:documentation>
+      This element contains one tuple (__getinitargs__),
+      and one dictionary (__dict__).
+      Its attributes are id, module and class
+      </xs:documentation>
+    </xs:annotation>
+    <xs:sequence>
+      <xs:element name="tuple" type="AllTypeList"/>
+      <xs:element name="dictionary" type="Dictionary"/>
+    </xs:sequence>
+    <xs:attribute name="id" type="xs:string" use="required"/>
+    <xs:attribute name="module" type="xs:string" use="required"/>
+    <xs:attribute name="class" type="xs:string" use="required"/>
+  </xs:complexType>
+
+  <xs:complexType name="List">
+    <xs:annotation>
+      <xs:documentation>
+      Extension of AllTypeList with id attribute
+      </xs:documentation>
+    </xs:annotation>
+    <xs:complexContent>
+      <xs:extension base="AllTypeList">
+        <xs:attribute name="id" type="xs:string" use="required"/>
+      </xs:extension>
+    </xs:complexContent>
+  </xs:complexType>
+
+  <xs:complexType name="Set">
+    <xs:annotation>
+      <xs:documentation>
+      Extension of AllTypeList with id attribute
+      </xs:documentation>
+    </xs:annotation>
+    <xs:complexContent>
+      <xs:extension base="AllTypeList">
+        <xs:attribute name="id" type="xs:string" use="required"/>
+      </xs:extension>
+    </xs:complexContent>
+  </xs:complexType>
+
+
+  <xs:complexType name="Dictionary">
+    <xs:annotation>
+      <xs:documentation>
+      Extension of AllTypeList with id attribute
+      Contains even occurences of AllTypeList
+      XXX can not be asserted with XSD
+      </xs:documentation>
+    </xs:annotation>
+    <xs:complexContent>
+      <xs:extension base="AllTypeList">
+        <xs:attribute name="id" type="xs:string" use="required"/>
+      </xs:extension>
+    </xs:complexContent>
+  </xs:complexType>
+
+  <xs:simpleType name="Boolean">
+    <xs:annotation>
+      <xs:documentation>
+        0 or 1
+      </xs:documentation>
+    </xs:annotation>
+    <xs:restriction base="xs:integer">
+      <xs:minInclusive value="0"/>
+      <xs:maxInclusive value="1"/>
+    </xs:restriction>
+  </xs:simpleType>
+
+  <xs:complexType name="AllTypeList">
+    <xs:choice minOccurs="0" maxOccurs="unbounded">
+      <xs:element name="tuple" type="AllTypeList"/>
+      <xs:element name="list" type="List"/>
+      <xs:element name="set" type="Set"/>
+      <xs:element name="dictionary" type="Dictionary"/>
+      <xs:element name="int" type="xs:integer"/>
+      <xs:element name="float" type="xs:float"/>
+      <xs:element name="long" type="xs:double"/>
+      <xs:element name="complex" type="Complex"/>
+      <xs:element name="string" type="xs:string"/>
+      <xs:element name="unicode" type="xs:string"/>
+      <xs:element name="object" type="Object"/>
+      <xs:element name="reference" type="Reference"/>
+      <xs:element name="code" type="xs:string"/>
+      <xs:element name="none" type="None"/>
+      <xs:element name="bool" type="Boolean"/>
+    </xs:choice>
+  </xs:complexType>
+
+  <!-- root Element -->
+
+  <xs:element name="marshal" type="AllTypeList">
+    <xs:annotation>
+      <xs:documentation>
+      Extension of AllTypeList.
+      Assert that all id attributes are unique
+      </xs:documentation>
+    </xs:annotation>
+    <xs:unique name="attribute_id">
+      <xs:selector xpath=".//object|.//list|.//dictionary"/>
+      <xs:field xpath="@id"/>
+    </xs:unique>
+    <xs:key name="id_list">
+      <xs:selector xpath=".//object|.//list|.//dictionary"/>
+      <xs:field xpath="@id"/>
+    </xs:key>
+    <xs:keyref  name="id_list_reference" refer="id_list">
+      <xs:selector xpath=".//reference"/>
+      <xs:field xpath="@id"/>
+    </xs:keyref> 
+  </xs:element>
+
+</xs:schema>
+
+