ldf.xsd

<xsd:schema
     xmlns:xsd="http://www.w3.org/2001/XMLSchema"
     xmlns:ldf="http://planet-sl.org/ldf"
     xmlns:bgf="http://planet-sl.org/bgf"
     xmlns:xhtml="http://www.w3.org/1999/xhtml/datatypes/"
     targetNamespace="http://planet-sl.org/ldf">

  <xsd:import namespace="http://planet-sl.org/bgf" schemaLocation="bgf.xsd"/>

  <!-- info -->
  <xsd:annotation>
    <xsd:documentation>
      Language Document Format
    </xsd:documentation>
    <xsd:documentation>
      This is basically a metamodel for language documents or documentations.

      Sample program tags:
      - External reference (with XPath-like subprogram selection)
      - Verbatim text + claim about corresponding grammar and nontermninal (and perhaps version)
      - Generation request for given grammar and nontermninal (and perhaps version, more control)
      - Sample suite extraction request (what are the constraints on the requested sample?)
    </xsd:documentation>
  </xsd:annotation>

  <!-- elements -->

  <xsd:element name="document">
    <xsd:annotation>
      <xsd:documentation>
        A document is essentially a sequence of several parts, such as title page, front matter,
        lexical and syntax sections, placeholders for generated content and various lists.
      </xsd:documentation>
    </xsd:annotation>
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="titlePage" type="ldf:titlePage"/>
        <xsd:element name="placeholder" type="ldf:generated" minOccurs="0" maxOccurs="unbounded"/>
        <xsd:element name="frontMatter">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:group ref="ldf:frontSection" maxOccurs="unbounded"/>
            </xsd:sequence>
          </xsd:complexType>
        </xsd:element>
        <xsd:element name="lists" minOccurs="0">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:group ref="ldf:frontList" maxOccurs="unbounded"/>
            </xsd:sequence>
          </xsd:complexType>
        </xsd:element>
        <xsd:element name="lexicalPart" minOccurs="0">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:group ref="ldf:lexicalSection" maxOccurs="unbounded"/>
            </xsd:sequence>
          </xsd:complexType>
        </xsd:element>
        <xsd:element name="core" type="ldf:structuredSection" maxOccurs="unbounded"/>
        <xsd:element name="annex" type="ldf:structuredSection" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>

  <xsd:complexType name="titlePage">
    <xsd:annotation>
      <xsd:documentation>
        The `title page' can in reality be rendered as several pages, but it contains the basic
        information that helps to identify this particular language definition and to distinguish
        it from similar documents. From our experience, language standards are either marked as
        organisation-created or person-authored ones. In the former case, the document must contain
        the name of the organisation and the standard reference number within it (e.g, ISO 10279).
        In the latter case, one or more authors are specified. It is also possible to mark some sections
        as having been authored by a specific set of authors, but the ones defined here are the principal
        authors that identify the specific standard.
      </xsd:documentation>
      <xsd:documentation>
        The `topic' of the language document is its pure textual title without the reference number
        and status: e.g., `Programming Language REXX',
        `Information technology --- Programming languages --- Full BASIC', etc. Either version or edition
        follows.
      </xsd:documentation>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:choice>
        <xsd:sequence>
          <xsd:element name="body" type="ldf:body"/>
          <xsd:element name="number" type="xsd:int"/>
        </xsd:sequence>
        <xsd:sequence>
          <xsd:element name="author" type="xsd:string" maxOccurs="unbounded"/>
        </xsd:sequence>
      </xsd:choice>
      <xsd:element name="topic" type="xsd:string"/>
      <xsd:choice>
        <xsd:element name="version" type="xsd:string" default="1.0"/>
        <xsd:element name="edition" type="xsd:string"/>
      </xsd:choice>
      <xsd:element name="status" type="ldf:status"/>
      <xsd:element name="date" type="xsd:string"/>
      <!-- xsd:date -->
    </xsd:sequence>
  </xsd:complexType>

  <xsd:simpleType name="body">
    <xsd:restriction base="xsd:token">
      <xsd:enumeration value="ansi"/>
      <xsd:enumeration value="ecma"/>
      <xsd:enumeration value="ieee"/>
      <xsd:enumeration value="iec"/>
      <xsd:enumeration value="iso"/>
      <xsd:enumeration value="iso/iet"/>
      <xsd:enumeration value="itu"/>
      <xsd:enumeration value="ietf"/>
      <xsd:enumeration value="iec"/>
      <xsd:enumeration value="oasis"/>
      <xsd:enumeration value="wsa"/>
      <xsd:enumeration value="w3c"/>
    </xsd:restriction>
  </xsd:simpleType>

  <xsd:simpleType name="status">
    <xsd:restriction base="xsd:token">
      <xsd:enumeration value="unknown"/>
      <xsd:enumeration value="draft"/>
      <xsd:enumeration value="committee draft"/>
      <xsd:enumeration value="recommendation"/>
      <xsd:enumeration value="international standard"/>
    </xsd:restriction>
  </xsd:simpleType>




  <!-- types of content -->
  <xsd:complexType name="listOfTerms">
    <xsd:sequence>
      <xsd:element name="title" type="xsd:string" minOccurs="0"/>
      <xsd:sequence>
        <xsd:element name="author" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:element name="term" maxOccurs="unbounded">
        <xsd:complexType>
          <xsd:sequence>
            <xsd:element name="name" type="xsd:string"/>
            <xsd:element name="definition" type="ldf:simpleText"/>
          </xsd:sequence>
        </xsd:complexType>
      </xsd:element>
    </xsd:sequence>
    <xsd:attribute name="id" type="xsd:ID" use="optional"/>
  </xsd:complexType>

  <xsd:complexType name="listOfInternalLinks">
    <xsd:sequence>
      <xsd:element name="link" maxOccurs="unbounded">
        <xsd:complexType>
          <xsd:sequence>
            <xsd:element name="text" type="xsd:string"/>
            <xsd:element name="linkText" type="xsd:string" minOccurs="0"/>
            <xsd:element name="reference" type="xsd:IDREF"/>
          </xsd:sequence>
        </xsd:complexType>
      </xsd:element>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:complexType name="simpleList">
    <xsd:sequence>
      <xsd:element name="item" type="ldf:mixedType" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:complexType name="simpleText">
    <xsd:sequence>
      <xsd:group ref="ldf:simpleTextElement" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:complexType name="tableRow">
    <xsd:sequence>
      <xsd:element name="cell" maxOccurs="unbounded" type="ldf:simpleText"/>
    </xsd:sequence>
  </xsd:complexType>
  
  <xsd:complexType name="simpleTable">
    <xsd:sequence>
      <xsd:element name="header" type="ldf:tableRow" minOccurs="0" maxOccurs="unbounded"/>
      <xsd:element name="row" type="ldf:tableRow" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:group name="simpleTextElement">
    <xsd:choice>
      <xsd:element name="empty" nillable="true">
        <xsd:complexType/>
      </xsd:element>
      <xsd:element name="text" type="ldf:mixedType"/>
      <xsd:element name="figure" type="ldf:simpleFigure"/>
      <xsd:element name="table" type="ldf:simpleTable"/>
      <xsd:element name="list" type="ldf:simpleList"/>
      <xsd:element name="formula" type="xsd:string"/>
      <xsd:element name="sample" type="xsd:string"/>
      <xsd:element ref="bgf:production"/>
      <!-- 	later redo with MathML -->
      <!--<xsd:element ref="mml:math"/>-->
    </xsd:choice>  
  </xsd:group>

  <xsd:complexType name="simpleFigure">
    <xsd:sequence>
      <xsd:element name="caption" type="xsd:string"/>
      <xsd:element name="type" type="xsd:string"/>
      <xsd:element name="file" type="xsd:string"/>
    </xsd:sequence>
    <xsd:attribute name="id" type="xsd:ID" use="optional"/>
  </xsd:complexType>

  <xsd:complexType name="simpleSection">
    <xsd:sequence>
      <xsd:element name="title" type="xsd:string" minOccurs="0"/>
      <xsd:sequence>
        <xsd:element name="author" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:element name="content" type="ldf:simpleText"/>
    </xsd:sequence>
    <xsd:attribute name="id" type="xsd:ID" use="optional"/>
  </xsd:complexType>

  <xsd:complexType name="structuredSection">
    <xsd:sequence>
      <xsd:element name="title" type="xsd:string"/>
      <xsd:sequence>
        <xsd:element name="author" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>
      </xsd:sequence>
      <xsd:group ref="ldf:structuredSectionElement" maxOccurs="unbounded" />
    </xsd:sequence>
    <xsd:attribute name="id" type="xsd:ID" use="optional"/>
  </xsd:complexType>

  <xsd:group name="structuredSectionElement">
    <xsd:choice>
      <xsd:element name="placeholder" type="ldf:generated"/>
      <xsd:group ref="ldf:normative"/>
      <xsd:group ref="ldf:informative"/>
      <xsd:element ref="bgf:production"/>
      <xsd:element name="relationship" type="ldf:listOfInternalLinks"/>
      <!-- <xsd:group ref="ldf:top-section"/> -->
      <xsd:element name="subtopic" type="ldf:structuredSection"/>
    </xsd:choice>
  </xsd:group>
  
  <!-- tokens -->

  <xsd:group name="normative">
    <xsd:choice>
      <xsd:element name="purpose" type="ldf:simpleSection"/>
      <xsd:element name="description" type="ldf:simpleSection"/>
      <xsd:element name="location" type="ldf:simpleSection"/>
      <xsd:element name="considerations" type="ldf:simpleSection"/>
      <xsd:element name="defaults" type="ldf:simpleSection"/>
      <!-- none of the above -->
      <xsd:element name="normative" type="ldf:simpleSection"/>
    </xsd:choice>
  </xsd:group>

  <xsd:group name="informative">
    <xsd:choice>
      <xsd:element name="note" type="ldf:simpleSection"/>
      <xsd:element name="example" type="ldf:simpleSection"/>
      <!-- none of the above -->
      <xsd:element name="informative" type="ldf:simpleSection"/>
    </xsd:choice>
  </xsd:group>

  <xsd:group name="lexicalSection">
    <xsd:annotation>
      <xsd:documentation>
        Sections describing lexical structure tend to be shorter, less structured inside,
        and very limited in scope: there is usually one on whitespace, one on tokens,
        one on literals, one on comments, etc.
      </xsd:documentation>
    </xsd:annotation>
    <xsd:choice>
      <xsd:element name="lineContinuations" type="ldf:simpleSection"/>
      <xsd:element name="whitespace" type="ldf:simpleSection"/>
      <xsd:element name="tokens" type="ldf:simpleSection"/>
      <xsd:element name="preprocessor" type="ldf:simpleSection"/>
      <xsd:element name="literals" type="ldf:simpleSection"/>
      <!-- none of the above -->
      <xsd:element name="lexical" type="ldf:simpleSection"/>
    </xsd:choice>
  </xsd:group>

   <xsd:simpleType name="generated">
    <xsd:restriction base="xsd:token">
      <xsd:enumeration value="index"/>
      <xsd:enumeration value="fullgrammar"/>
      <xsd:enumeration value="listoftables"/>
      <xsd:enumeration value="listofauthors"/>
      <xsd:enumeration value="listofcontents"/>
      <xsd:enumeration value="listofreferences"/>
    </xsd:restriction>
  </xsd:simpleType>



 <xsd:group name="frontSection">
    <xsd:choice>
      <xsd:element name="foreword" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            Whatever the authors deem to be important enough to be put on one of the first
            pages. For example, in C\# specifications Foreword is about the differences brought
            to the language by the current standard, while in the Scheme specification
            Foreword discusses programming languages design and demonstrates its principles
            applied to the forthcoming document.
          </xsd:documentation>
          <xsd:documentation>
            Technically speaking, Foreword is not a part of the specification. Instead, it
            precedes the specification and introduces it by putting in the proper context.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="designGoals" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            The goals of language design are sometimes encounted being explicitly
            stated in the language document in one of the informative sections
            of the front matter part.
          </xsd:documentation>
          <xsd:documentation>
            For example:
            "C\# is intended to be a simple, modern, general-purpose, object-oriented
            programming language."
            (from ECMA 334 3rd edition, page xvii)
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="scope" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            Scope section explains the context for the language document.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="conformance" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            Conformance section defines several levels of compliance by
            explaining what is a conforming program and a conforming
            implementation with respect to this standard.
          </xsd:documentation>
          <xsd:documentation>
            Definitions for meta-terms like "shall" and "should"
            and their relation to the compliance issue explained above.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="compliance" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            Same as conformance
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="compatibility" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            While conformance/compliance define how external artifacts should
            conform to this standard, this section defines how this standard
            complies with previously existing ones.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="notation" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            Notation section defines grammar definition formalism used in the document:
            mostly it is about the EBNF dialect.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="normativeReferences" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            Formally lined up references to all other standards that are used or referenced to
            from within the document.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="documentStructure" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            This section informally describes how the document is organised, divided
            into parts and chapters. Sometimes it explicitly states which sections are
            normative and which are informative.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="whatsnew" type="ldf:simpleSection">
        <xsd:annotation>
          <xsd:documentation>
            A list of changes brought to the language by the current specification
            replacing the previous one.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="clause" type="ldf:simpleSection"/>
      <xsd:element name="field" type="ldf:simpleSection"/>
      <!-- none of the above 
      <xsd:element name="core" type="ldf:simpleSection"/>
      -->
    </xsd:choice>
  </xsd:group>

  <xsd:group name="frontList">
    <xsd:choice>
      <xsd:element name="definitions" type="ldf:listOfTerms">
        <xsd:annotation>
          <xsd:documentation>
            This is a list of definitions for all basic terms needed to understand the document,
            but not especially introduced in it. Typical examples include explaining what is
            a "program", what is a "namespace", what is a "library", what is "behaviour".
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="abbreviations" type="ldf:listOfTerms">
        <xsd:annotation>
          <xsd:documentation>
            Acronyms like IEEE, ISO or like CLI, BCL are frequently defined here in a separate definition list.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="languageOverview" type="ldf:listOfTerms">
        <xsd:annotation>
          <xsd:documentation>
            Such an informal introduction to the language is not present in all standards.
            However, some specifications contain a not claimed to be complete list of
            language concepts with their definitions and perhaps even some examples.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
    </xsd:choice>
  </xsd:group>

    <!--xsd:complexType name="contentType">
    <xsd:annotation>
      <xsd:documentation>
        A sections content is a list of different kinds of portions.
        Text is one kind of portion.
        A grammar fragment is another kind of portion.
        A sample is yet another kind of portion.
      </xsd:documentation>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:choice minOccurs="0" maxOccurs="unbounded">
        <xsd:element name="text" type="ldf:mixedType"/>
        <xsd:element name="grammar">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:any namespace="http://planet-sl.org/bgf" maxOccurs="unbounded"/>
            </xsd:sequence>
            <xsd:attribute name="language" type="xsd:anyURI" use="required"/>
            <xsd:attribute name="version" type="xsd:token" use="optional"/>
          </xsd:complexType>
        </xsd:element>
        <xsd:element name="sample" type="ldf:informative"/>
        <xsd:element name="runnable" type="ldf:runnableType"/>
      </xsd:choice>
      <xsd:element name="section" type="ldf:section" minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
  </xsd:complexType-->

  <xsd:complexType name="runnableType">
    <xsd:annotation>
      <xsd:documentation>
        Related to the sample, this element shows a way to run a sample.
        In FL, it is always just a name of one of the functions and the list of its parameters.
        Generally, while keeping the internal structure of this element as such,
        one might want to represent it in the resulting language document differently
        (i.e. "java Test a b c" instead of "main(a,b,c);" ).
      </xsd:documentation>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:element name="context" type="xsd:IDREF">
        <xsd:annotation>
          <xsd:documentation>
            The reference to another sample that must be used
            as a context while evaluating this one
            The means to refer to this particular sample later in the same document.
            For example, this sample introduces a function that is used in one of the next samples.
            It can also be a full text of a program that is run with different set of attributes later.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="main" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            The main function that is applied to the arguments.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="argument" type="xsd:string" minOccurs="0" maxOccurs="unbounded">
        <xsd:annotation>
          <xsd:documentation>
            These arguments are passed to the function during execution.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
      <xsd:element name="yields" type="xsd:string">
        <xsd:annotation>
          <xsd:documentation>
            The value that the sample should yield if parsed and
            evalutated in the specified language.
          </xsd:documentation>
        </xsd:annotation>
      </xsd:element>
    </xsd:sequence>
    <xsd:attribute name="language" type="xsd:anyURI" use="required"/>
    <xsd:attribute name="version" type="xsd:token" use="optional"/>
    <xsd:attribute name="id" type="xsd:ID" use="optional">
      <xsd:annotation>
        <xsd:documentation>
          The means to refer to this particular sample later in the same document.
          For example, this sample introduces a function that is used in one of the next samples.
          It can also be a full text of a program that is run with different set of attributes later.
        </xsd:documentation>
      </xsd:annotation>
    </xsd:attribute>
  </xsd:complexType>

  <!--xsd:complexType name="sectionTypeodl">
    <xsd:annotation>
      <xsd:documentation>
        A section has a title, some content, and possibly a list of subsections.
      </xsd:documentation>
    </xsd:annotation>
    <xsd:sequence>
      <xsd:element name="title" type="xsd:string"/>
      <xsd:element name="content" type="ldf:contentType"/>
    </xsd:sequence>
  </xsd:complexType-->

  <xsd:complexType name="mixedType" mixed="true">
    <xsd:sequence minOccurs="0" maxOccurs="unbounded">
      <xsd:any namespace="http://planet-sl.org/ldf" processContents="lax"/>
    </xsd:sequence>
    <!--<xsd:anyAttribute namespace="##other" processContents="lax"/>-->
  </xsd:complexType>

  <xsd:element name="keyword" type="xsd:string">
    <xsd:annotation>
      <xsd:documentation>
        Keywords are usually printed in bolder font weight.
      </xsd:documentation>
    </xsd:annotation>
  </xsd:element>

</xsd:schema>