<?xml version="1.0" encoding="utf-8" ?>

<!--
  Copyright (c) 1997-2021
  Ewgenij Gawrilow, Michael Joswig, and the polymake team
  Technische Universität Berlin, Germany
  https://polymake.org

  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version: http://www.gnu.org/licenses/gpl.txt.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
===============================================================================

  Relax-NG Schema for polymake v3 data file

  XML-based data format was used in releases 2.9 up to 3.6.

  This schema is preserved mainly for historical reasons, if someone needs to validate
  data files left behind old polymake releases.

  Please note that polymake automatically converts XML data files into JSON format
  but does not validate them against the schema.
-->

<grammar xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes"
         xmlns:note="http://www.math.tu-berlin.de/polymake/note"
         ns="http://www.math.tu-berlin.de/polymake/#3">

  <start>
    <choice>
      <ref name="TopObject" />
      <ref name="LooseData" />
    </choice>
  </start>

  <define name="TopObject">
    <element name="object">
      <ref name="TopAttribs" />
      <ref name="ObjectContent" />
    </element>
  </define>

  <define name="TopAttribs">
    <note:a> type prefixed by an application name </note:a>
    <attribute name="type">
      <data type="string">
        <param name="pattern">[a-zA-Z][a-zA-Z_0-9]*::.*</param>
      </data>
    </attribute>

    <note:a>
      version refers to the polymake implementation which has
      created this data instance.
    </note:a>
    <optional>
      <attribute name="version">
        <data type="string">
          <param name="pattern">\d+(\.\d+)*</param>
        </data>
      </attribute>
    </optional>
  </define>

  <define name="LooseData">
    <element name="data">
      <ref name="TopAttribs" />
      <ref name="Extensions" />
      <optional>
        <element name="description">
          <text/>
        </element>
      </optional>
      <ref name="PropertyData" />
    </element>
  </define>

  <define name="SubObject">
    <element name="object">
      <optional>
        <note:a> The type defaults to the declared property type </note:a>
        <attribute name="type" />
      </optional>
      <ref name="ObjectContent" />
    </element>
  </define>

  <define name="SimpleName">
    <attribute name="name">
      <data type="string">
        <param name="pattern">[a-zA-Z][a-zA-Z_0-9]*</param>
      </data>
    </attribute>
  </define>

  <define name="PropertyName">
    <attribute name="name">
      <note:a>
        Must be prefixed by the name of the application where this property is introduced
        if that is different from the application where the owning object is defined
        (aka property injection).
      </note:a>
      <data type="string">
        <param name="pattern">([a-zA-Z][a-zA-Z_0-9]*::)?[a-zA-Z][a-zA-Z_0-9]*</param>
      </data>
    </attribute>
  </define>

  <define name="Extensions">
    <optional>
      <attribute name="ext">
        <note:a>
          The first reference to any extension in the document order must consist
          of the ordinal number and the URI; all subsequent references are solely numbers.
        </note:a>
        <data type="string">
          <param name="pattern">( *\d+(=[^\s#]+(#\d+)?)?)+ *</param>
        </data>
      </attribute>
    </optional>
  </define>

  <define name="ObjectTextDescriptions">
    <optional>
      <attribute name="name" />
    </optional>
    <optional>
      <element name="description">
        <text/>
      </element>
    </optional>
    <zeroOrMore>
      <element name="credit">
        <attribute name="product" />
        <text/>
      </element>
    </zeroOrMore>
  </define>

  <define name="ObjectContent">
    <ref name="Extensions" />
    <ref name="ObjectTextDescriptions" />
    <interleave>
      <zeroOrMore>
        <ref name="Property" />
      </zeroOrMore>
      <zeroOrMore>
        <ref name="Attachment" />
      </zeroOrMore>
    </interleave>
  </define>

  <define name="Property">
    <element name="property">
      <ref name="PropertyName" />
      <ref name="Extensions" />
      <choice>
        <group>
          <note:a>
            undefined value is signaled by the special attribute
          </note:a>
          <attribute name="undef"><value>true</value></attribute>
          <empty/>
        </group>

        <group>
 	  <note:a>
            type defaults to the declared property type
          </note:a>
          <optional>
            <attribute name="type" />
          </optional>
          <ref name="PropertyData" />
        </group>

        <ref name="Text" />

        <oneOrMore>
	  <ref name="SubObject" />
        </oneOrMore>
      </choice>
    </element>
  </define>

  <define name="Attachment">
    <element name="attachment">
      <ref name="SimpleName" />
      <ref name="Extensions" />
      <ref name="AttachmentData" />
    </element>
  </define>

  <define name="PropertyData">
    <choice>
      <note:a>
        Scalar property values may be stored in the value attribute,
	saving space and improving legibility.
      </note:a>
      <group>
        <attribute name="value" />
        <empty/>
      </group>

      <ref name="Complex" />

      <note:a> Array of (sub-)objects. </note:a>
      <element name="m">
        <oneOrMore>
	  <ref name="SubObject" />
        </oneOrMore>
      </element>
    </choice>
  </define>

  <define name="AttachmentData">
    <choice>
      <note:a>
        Scalar property values may be stored in the value attribute,
	saving space and improving legibility.
	Default type is String.
      </note:a>
      <group>
        <optional>
          <attribute name="type" />
        </optional>
        <attribute name="value" />
        <empty/>
      </group>

      <group>
        <attribute name="type" />
        <optional>
          <note:a>
            Property path in dotted notation, referring to the enclosing object.
            The property is passed to the constructor of the data stored in this attachment.
          </note:a>
          <attribute name="construct" />
        </optional>
        <ref name="Complex" />
      </group>

      <ref name="Text" />
    </choice>
  </define>

  <define name="Text">
    <note:a>
      Unstructured text must be declared explicitly by the type attribute.
      The contents are expected to be enclosed in CDATA brackets to preserve line breaks etc.
    </note:a>
    <attribute name="type"><value>text</value></attribute>
    <text/>
  </define>

  <define name="Complex">
    <choice>
      <ref name="Vector" />
      <ref name="Matrix" />
      <ref name="Tuple" />
    </choice>
  </define>

  <define name="VectorContents">
    <choice>
      <note:a> A dense vector with simple scalar elements </note:a>
      <list>
        <oneOrMore>
          <data type="string" />
        </oneOrMore>
      </list>
      <note:a> A dense vector with complex elements </note:a>
      <oneOrMore>
        <ref name="Tuple" />
      </oneOrMore>
      <note:a> A sparse vector </note:a>
      <group>
        <note:a>
          Vector dimension; if omitted, the cols attribute of the enclosing matrix has to be taken.
        </note:a>
        <optional>
          <ref name="SparseContainerDim" />
        </optional>
        <choice>
          <note:a> simple scalar elements; this choice matches an empty vector as well </note:a>
          <zeroOrMore>
            <element name="e">
              <ref name="ElementIndex" />
              <data type="string" />
            </element>
          </zeroOrMore>
          <note:a> complex elements </note:a>
          <oneOrMore>
            <element name="t">
              <ref name="ElementIndex" />
              <ref name="TupleContents" />
            </element>
          </oneOrMore>
        </choice>
      </group>
    </choice>
  </define>

  <note:a> index of an element in a sparse container </note:a>
  <define name="ElementIndex">
    <attribute name="i">
      <data type="nonNegativeInteger" />
    </attribute>
  </define>

  <note:a> dimension of a sparse container </note:a>
  <define name="SparseContainerDim">
     <attribute name="dim">
      <data type="nonNegativeInteger" />
    </attribute>
  </define>

  <note:a> number of columns in a matrix </note:a>
  <define name="NumberColumns">
     <attribute name="cols">
      <data type="nonNegativeInteger" />
    </attribute>
  </define>

  <note:a> data instance referred to from other places in the document </note:a>
  <define name="IdAttribute">
    <attribute name="id">
      <data type="nonNegativeInteger" />
    </attribute>
  </define>

  <define name="Vector">
    <element name="v">
      <ref name="VectorContents" />
    </element>
  </define>

  <define name="MatrixContents">
    <note:a> a matrix or a list of complex elements </note:a>
    <choice>
      <group>
        <note:a> cols attribute applies to sparse matrices </note:a>
        <optional>
          <ref name="NumberColumns" />
        </optional>
        <zeroOrMore>
          <ref name="Vector" />
        </zeroOrMore>
      </group>
      <group>
        <note:a>
          sparse container of complex elements, like graph with gaps left over from deleted nodes
        </note:a>
        <ref name="SparseContainerDim" />
        <optional>
          <ref name="NumberColumns" />
        </optional>
        <zeroOrMore>
          <element name="v">
            <ref name="ElementIndex" />
            <ref name="VectorContents" />
          </element>
        </zeroOrMore>
      </group>
      <oneOrMore>
        <ref name="Matrix" />
      </oneOrMore>
      <oneOrMore>
        <ref name="Tuple" />
      </oneOrMore>
    </choice>
  </define>

  <define name="Matrix">
    <element name="m">
      <ref name="MatrixContents" />
    </element>
  </define>

  <define name="TupleContents">
    <note:a> a heterogeneous ordered list </note:a>
    <choice>
      <note:a> all elements are simple acalars </note:a>
      <list>
        <oneOrMore>
          <data type="string" />
        </oneOrMore>
      </list>
      <note:a> at least one complex element </note:a>
      <oneOrMore>
        <choice>
          <ref name="Vector" />
          <ref name="Matrix" />
          <ref name="Tuple" />
          <element name="e">
            <data type="string" />
          </element>
        </choice>
      </oneOrMore>
    </choice>
  </define>

  <define name="Tuple">
    <element name="t">
      <ref name="TupleContents" />
    </element>
  </define>

</grammar>
