# ===========================================================================
#
# XML Topic Maps 2.0
#
# This is the normative RELAX-NG schema for the XTM 2.0 syntax, as
# defined in ISO 13250-3.
#
# See http://www.isotopicmaps.org/sam/sam-xtm/
#
# ===========================================================================

# --- Common declarations

default namespace = "http://www.topicmaps.org/xtm/"
namespace xtm = "http://www.topicmaps.org/xtm/"

datatypes xsd = "http://www.w3.org/2001/XMLSchema-datatypes"

start = topicMap

reifiable = attribute reifier { xsd:anyURI }?, itemIdentity*
href = attribute href { xsd:anyURI }

any-markup = (text | element * - xtm:* { attribute * { text }*, any-markup* })*


# --- The schema

topicMap = element topicMap { reifiable, version, mergeMap*,
                              (topic | association)* }

version = attribute version { "2.0" }

topic = element topic { id, 
                        (itemIdentity | subjectLocator | subjectIdentifier)*,
                        instanceOf?, (name | occurrence)* }
id = attribute id { xsd:ID }

name = element name { reifiable, type?, scope?, value, variant* }

value = element value { text }

variant = element variant { reifiable, scope, (resourceRef | resourceData) }

scope = element scope { topicRef+ }

instanceOf = element instanceOf { topicRef+ }

type = element type { topicRef }

occurrence = element occurrence { reifiable,
  type, scope?, ( resourceRef | resourceData ) }

datatype = attribute datatype { xsd:anyURI }

resourceData = element resourceData { datatype?, any-markup }

association = element association { reifiable, type, scope?, role+ }

role = element role { reifiable, type, topicRef }

topicRef = element topicRef { href }
resourceRef = element resourceRef { href }
subjectLocator = element subjectLocator { href }
subjectIdentifier = element subjectIdentifier { href }
itemIdentity = element itemIdentity { href }

mergeMap = element mergeMap { href }

# --- End of schema