# source file: yin.rng

default namespace = "urn:ietf:params:xml:ns:yang:yin:1"
namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"
namespace dc = "http://purl.org/dc/terms"

dc:title [ "RELAX NG Schema for YIN" ]
dc:creator [ "Ladislav Lhotka" ]
dc:date [ "2009-03-03" ]
dc:subject [ "YIN, XML syntax for YANG" ]
dc:identifier [ "urn:ietf:params:xml:ns:yang:yin:1" ]
dc:description [
  "RELAX NG schema defines grammar for data models\x{a}" ~
  "  expressed in YIN, an XML syntax equivalent to YANG."
]

## The document element may be either "module" or "submodule.
start = module-stmt | submodule-stmt
module-stmt =
  element module {
    attribute name { identifier },
    module-header-stmts,
    linkage-stmts,
    meta-stmts,
    revision-stmts,
    body-stmts
  }
submodule-stmt =
  element submodule {
    attribute name { identifier },
    submodule-header-stmts,
    linkage-stmts,
    meta-stmts,
    revision-stmts,
    body-stmts
  }
module-header-stmts = yang-version-stmt? & namespace-stmt & prefix-stmt
submodule-header-stmts = yang-version-stmt? & belongs-to-stmt
meta-stmts =
  organization-stmt?
  & contact-stmt?
  & description-stmt?
  & reference-stmt?
linkage-stmts = (import-stmt | include-stmt)*
revision-stmts = revision-stmt*
body-stmts =
  (feature-stmt
   | identity-stmt
   | extension-stmt
   | typedef-stmt
   | grouping-stmt
   | data-def-stmt
   | rpc-stmt
   | notification-stmt)*
feature-stmt =
  element feature {
    attribute name { identifier },
    if-feature-stmt*,
    status-stmt?,
    description-stmt?,
    reference-stmt?
  }
if-feature-stmt =
  element if-feature {
    attribute name { identifier }
  }
identity-stmt =
  element identity {
    attribute name { identifier },
    base-stmt?
  }
base-stmt =
  element base {
    attribute name { identifier-ref }
  }
data-def-stmt =
  container-stmt
  | leaf-stmt
  | leaf-list-stmt
  | list-stmt
  | choice-stmt
  | anyxml-stmt
  | uses-stmt
  | augment-stmt
case-data-def-stmt =
  container-stmt
  | leaf-stmt
  | leaf-list-stmt
  | list-stmt
  | anyxml-stmt
  | uses-stmt
  | augment-stmt
yang-version-stmt =
  element yang-version {
    attribute value { "1" }
  }
import-stmt =
  element import {
    attribute module { identifier },
    prefix-stmt
  }
include-stmt =
  element include {
    attribute module { identifier }
  }
namespace-stmt =
  element namespace {
    attribute uri { xsd:anyURI }
  }
prefix-stmt =
  element prefix {
    attribute value { identifier }
  }
belongs-to-stmt =
  element belongs-to {
    attribute module { identifier },
    prefix-stmt
  }
organization-stmt =
  element organization {
    element info { text }
  }
contact-stmt =
  element contact {
    element info { text }
  }
description-stmt =
  element description {
    element text { text }
  }
reference-stmt =
  element reference {
    attribute info { xsd:string }
  }
units-stmt =
  element units {
    attribute name { xsd:string }
  }
revision-stmt =
  element revision {
    attribute date { xsd:date },
    description-stmt?
  }
extension-stmt =
  element extension {
    attribute name { identifier },
    argument-stmt?,
    status-stmt?,
    description-stmt?,
    reference-stmt?
  }
argument-stmt =
  element argument {
    attribute name { identifier },
    yin-element-stmt?
  }
yin-element-stmt =
  element yin-element {
    attribute value { xsd:boolean }
  }
typedef-stmt =
  element typedef {
    attribute name { identifier },
    (type-stmt
     & units-stmt?
     & default-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?)
  }
type-stmt =
  element type {
    (attribute name { identifier-ref },
     (range-stmt | (length-stmt & pattern-stmts)))
    | numeric-type
    | string-type
    | enumeration-type
    | bits-type
    | binary-type
    | leafref-type
    | identityref-type
    | union-type
    | instance-identifier-type
  }
numeric-type =
  attribute name {
    "int8"
    | "int16"
    | "int32"
    | "int64"
    | "uint8"
    | "uint16"
    | "uint32"
    | "uint64"
    | "float32"
    | "float64"
  },
  range-stmt
range-stmt =
  element range {
    attribute value { range-expr },
    (error-message-stmt?
     & error-app-tag-stmt?
     & description-stmt?
     & reference-stmt?)
  }?
string-type =
  attribute name { "string" },
  (length-stmt & pattern-stmts)
length-stmt =
  element length {
    attribute value { length-expr },
    (error-message-stmt?
     & error-app-tag-stmt?
     & description-stmt?
     & reference-stmt?)
  }?
pattern-stmts =
  element pattern {
    attribute value { xsd:string },
    (error-message-stmt?
     & error-app-tag-stmt?
     & description-stmt?
     & reference-stmt?)
  }*
default-stmt =
  element default {
    attribute value { xsd:string }
  }
enumeration-type =
  attribute name { "enumeration" },
  enum-stmt+
enum-stmt =
  element enum {
    attribute name { identifier },
    (value-stmt? & status-stmt? & description-stmt? & reference-stmt?)
  }
bits-type =
  attribute name { "bits" },
  bit-stmt+
bit-stmt =
  element bit {
    attribute name { identifier },
    (position-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?)
  }
position-stmt =
  element position {
    attribute value { xsd:nonNegativeInteger }
  }
binary-type =
  attribute name { "binary" },
  length-stmt?
leafref-type =
  attribute name { "leafref" },
  (element path {
     attribute value { path-arg }
   }
   & require-instance-element?)
require-instance-element = element require-instance { xsd:boolean }
identityref-type =
  attribute name { "identityref" },
  base-stmt
union-type =
  attribute name { "union" },
  type-stmt+
instance-identifier-type =
  attribute name { "instance-identifier" },
  require-instance-element?
status-stmt =
  element status {
    attribute value { status-arg }
  }
status-arg = "current" | "obsolete" | "deprecated"
config-stmt =
  element config {
    attribute value { xsd:boolean }
  }
mandatory-stmt =
  element mandatory {
    attribute value { xsd:boolean }
  }
presence-stmt =
  element presence {
    attribute value { xsd:string }
  }
ordered-by-stmt =
  element ordered-by {
    attribute value { ordered-by-arg }
  }
ordered-by-arg = "user" | "system"
must-stmt =
  element must {
    attribute condition { xsd:string },
    (error-message-stmt?
     & error-app-tag-stmt?
     & description-stmt?
     & reference-stmt?)
  }
error-message-stmt =
  element error-message {
    element value { text }
  }
error-app-tag-stmt =
  element error-app-tag {
    attribute value { xsd:string }
  }
min-elements-stmt =
  element min-elements {
    attribute value { xsd:nonNegativeInteger }
  }
max-elements-stmt =
  element max-elements {
    attribute value { "unbounded" | xsd:positiveInteger }
  }
value-stmt =
  element value {
    attribute value { xsd:integer }
  }
grouping-stmt =
  element grouping {
    attribute name { identifier },
    (status-stmt?
     & description-stmt?
     & reference-stmt?
     & (typedef-stmt | grouping-stmt | data-def-stmt)*)
  }
container-stmt =
  element container {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & must-stmt*
     & presence-stmt?
     & config-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (typedef-stmt | grouping-stmt | data-def-stmt)*)
  }
leaf-stmt =
  element leaf {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & type-stmt
     & units-stmt?
     & must-stmt*
     & default-stmt?
     & config-stmt?
     & mandatory-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?)
  }
leaf-list-stmt =
  element leaf-list {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & type-stmt
     & units-stmt?
     & must-stmt*
     & config-stmt?
     & min-elements-stmt?
     & max-elements-stmt?
     & ordered-by-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?)
  }
list-stmt =
  element list {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & must-stmt*
     & key-stmt?
     & unique-stmt*
     & config-stmt?
     & min-elements-stmt?
     & max-elements-stmt?
     & ordered-by-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (typedef-stmt | grouping-stmt)*
     & data-def-stmt+)
  }
key-stmt =
  element key {
    attribute value {
      list { identifier+ }
    }
  }
unique-stmt =
  element unique {
    attribute tag {
      list { descendant-schema-nodeid+ }
    }
  }
choice-stmt =
  element choice {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & default-stmt?
     & config-stmt?
     & mandatory-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (short-case-stmt | case-stmt)*)
  }
short-case-stmt =
  container-stmt | leaf-stmt | leaf-list-stmt | list-stmt | anyxml-stmt
case-stmt =
  element case {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & case-data-def-stmt*)
  }
anyxml-stmt =
  element anyxml {
    attribute name { identifier },
    (when-stmt?
     & if-feature-stmt*
     & must-stmt*
     & config-stmt?
     & mandatory-stmt?
     & status-stmt?
     & description-stmt?
     & reference-stmt?)
  }
uses-stmt =
  element uses {
    attribute name { identifier-ref },
    (when-stmt?
     & if-feature-stmt*
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & refine-stmt*
     & uses-augment-stmt*)
  }
refine-stmt =
  element refine {
    attribute target-node { descendant-schema-nodeid },
    (refine-container-stmts
     | refine-leaf-stmts
     | refine-leaf-list-stmts
     | refine-list-stmts
     | refine-choice-stmts
     | refine-case-stmts
     | refine-anyxml-stmts)
  }
refine-container-stmts =
  must-stmt*
  & presence-stmt?
  & config-stmt?
  & description-stmt?
  & reference-stmt?
refine-leaf-stmts =
  must-stmt*
  & default-stmt?
  & config-stmt?
  & mandatory-stmt?
  & description-stmt?
  & reference-stmt?
refine-leaf-list-stmts =
  must-stmt*
  & config-stmt?
  & min-elements-stmt?
  & max-elements-stmt?
  & description-stmt?
  & reference-stmt?
refine-list-stmts =
  must-stmt*
  & config-stmt?
  & min-elements-stmt?
  & max-elements-stmt?
  & description-stmt?
  & reference-stmt?
refine-choice-stmts =
  default-stmt?
  & config-stmt?
  & mandatory-stmt?
  & description-stmt?
  & reference-stmt?
refine-case-stmts = description-stmt? & reference-stmt?
refine-anyxml-stmts =
  config-stmt? & mandatory-stmt? & description-stmt? & reference-stmt?
uses-augment-stmt =
  element augment {
    attribute target-node { descendant-schema-nodeid },
    (when-stmt?
     & if-feature-stmt*
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (data-def-stmt | case-stmt)+)
  }
augment-stmt =
  element augment {
    attribute target-node { absolute-schema-nodeid },
    (when-stmt?
     & if-feature-stmt*
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (data-def-stmt | case-stmt)+)
  }
when-stmt =
  element when {
    attribute condition { xsd:string }
  }
rpc-stmt =
  element rpc {
    attribute name { identifier },
    (if-feature-stmt*
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (typedef-stmt | grouping-stmt)*),
    input-stmt?,
    output-stmt?
  }
input-stmt =
  element input { (typedef-stmt | grouping-stmt)* & data-def-stmt+ }
output-stmt =
  element output { (typedef-stmt | grouping-stmt)* & data-def-stmt+ }
notification-stmt =
  element notification {
    attribute name { identifier },
    (if-feature-stmt*
     & status-stmt?
     & description-stmt?
     & reference-stmt?
     & (typedef-stmt | grouping-stmt | data-def-stmt)*)
  }
# Regular expressions for lexical terms
identifier = xsd:NCName { pattern = "[_A-Za-z][_\-A-Za-z0-9.]*" }
identifier-ref =
  xsd:Name {
    pattern = "([_A-Za-z][_\-A-Za-z0-9.]*:)?[_A-Za-z][_\-A-Za-z0-9.]*"
  }
range-expr =
  xsd:string {
    pattern =
      "\s*(-INF|INF|min|max|\-?(0|[1-9][0-9]*)(\.[0-9]+(E[\-+]?[0-9]+)?)?)(\s*\.\.\s*(-INF|INF|min|max|\-?(0|[1-9][0-9]*)(\.[0-9]+(E[\-+]?[0-9]+)?)?))?(\s*\|\s*(-INF|INF|min|max|\-?(0|[1-9][0-9]*)(\.[0-9]+(E[\-+]?[0-9]+)?)?)(\s*\.\.\s*(-INF|INF|min|max|\-?(0|[1-9][0-9]*)(\.[0-9]+(E[\-+]?[0-9]+)?)?))?)*\s*"
  }
length-expr =
  xsd:string {
    pattern =
      "\s*(min|max|(0|[1-9][0-9]*))(\s*\.\.\s*(min|max|(0|[1-9][0-9]*)))?(\s*\|\s*(min|max|(0|[1-9][0-9]*))(\s*\.\.\s*(min|max|(0|[1-9][0-9]*)))?)*\s*"
  }
path-arg =
  xsd:string {
    pattern =
      "((/([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*(\[\s*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*\s*=\s*([$]this/(\.\./)+(([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*/)*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*)\s*\])*)+|(\.\./)*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*(\[\s*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*\s*=\s*([$]this/(\.\./)+(([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*/)*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*)\s*\])?(/([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*(\[\s*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*\s*=\s*([$]this/(\.\./)+(([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*/)*([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*)\s*\])*)+)"
  }
absolute-schema-nodeid =
  xsd:string {
    pattern =
      "(/([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*)+"
  }
descendant-schema-nodeid =
  xsd:string {
    pattern =
      "([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*(/([_A-Za-z][._\-A-Za-z0-9]*:)?[_A-Za-z][._\-A-Za-z0-9]*)*"
  }