From: http://www.ietf.org/internet-drafts/draft-legg-xed-asd-07.txt Title: Abstract Syntax Notation X (ASN.X) Reference: IETF Internet Draft Date: December 22, 2006 I-D Tracker: http://ietfreport.isoc.org/idref/draft-legg-xed-asd/ ============================================================================== INTERNET-DRAFT S. Legg draft-legg-xed-asd-07.txt eB2Bcom Intended Category: Standards Track December 22, 2006 Abstract Syntax Notation X (ASN.X) Copyright (C) The IETF Trust (2006). Status of This Memo By submitting this Internet-draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress". The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Technical discussion of this document should take place on the XED developers mailing list . Please send editorial comments directly to the editor . Further information is available on the XED website: www.xmled.info. This Internet-Draft expires on 22 June 2007. Abstract Abstract Syntax Notation X (ASN.X) is a semantically equivalent Extensible Markup Language (XML) representation for Abstract Syntax Notation One (ASN.1) specifications. ASN.X completely avoids the numerous ambiguities inherent in the ASN.1 language, therefore specifications written in ASN.X are much easier to parse and manage than original ASN.1 specifications. ASN.X, together with the Robust Legg Expires 22 June 2007 [Page 1] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 XML Encoding Rules (RXER), constitutes a schema language for XML documents that offers, through other ASN.1 encoding rules, alternative compact binary encodings for XML instance documents. Table of Contents 1. Introduction ....................................................3 2. Conventions .....................................................5 3. General Considerations ..........................................5 3.1. Annotations ................................................7 4. ModuleDefinition Translation ....................................8 5. Translation of Assignments .....................................10 5.1. Referencing Named Constructs ..............................11 5.2. Importing Namespaces ......................................12 5.3. TypeAssignment Translation ................................13 5.4. ValueAssignment and XMLValueAssignment Translation ........14 5.5. ValueSetTypeAssignment Translation ........................14 5.6. ObjectClassAssignment Translation .........................15 5.7. ObjectAssignment Translation ..............................15 5.8. ObjectSetAssignment Translation ...........................16 5.9. ParameterizedAssignment Translation .......................17 6. Translation of Types ...........................................17 6.1. Identifier Replacement ....................................17 6.2. DefinedType Translation ...................................18 6.3. Translation of Built-in Types .............................20 6.4. BitStringType Translation .................................21 6.5. IntegerType Translation ...................................22 6.6. EnumeratedType Translation ................................23 6.7. PrefixedType Translation ..................................25 6.7.1. Short Form TaggedType Translation ..................27 6.7.2. Long Form TaggedType Translation ...................28 6.8. SelectionType Translation .................................29 6.9. InstanceOfType Translation ................................30 6.10. ObjectClassFieldType Translation .........................31 6.11. TypeFromObject and ValueSetFromObjects Translation .......31 6.12. Translation of Combining Types ...........................32 6.12.1. NamedType Translation .............................32 6.12.2. SequenceType Translation ..........................36 6.12.3. SetType Translation ...............................38 6.12.4. ChoiceType Translation ............................38 6.12.5. Translation of UNION Types ........................39 6.12.6. SequenceOfType Translation ........................40 6.12.7. Translation of LIST Types .........................41 6.12.8. SetOfType Translation .............................41 6.12.9. Effect of Insertion Encoding Instructions .........42 6.13. Translation of Constrained Types .........................42 6.13.1. Constraint Translation ............................45 6.13.2. UserDefinedConstraint Translation .................45 Legg Expires 22 June 2007 [Page 2] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.13.3. TableConstraint Translation .......................46 6.13.4. ContentsConstraint Translation ....................48 6.13.5. ExceptionSpec Translation .........................49 7. Translation of Values ..........................................50 7.1. Translation of Literal Values .............................51 7.2. Translation of Notational Values ..........................53 7.2.1. DefinedValue Translation ...........................54 7.2.2. BuiltinValue Translation ...........................55 7.2.3. ValueFromObject Translation ........................59 7.2.4. ObjectClassFieldValue Translation ..................59 8. Translation of Value Sets ......................................60 8.1. ElementSetSpecs Translation ...............................60 8.2. ElementSetSpec Translation ................................61 8.3. SubtypeElements Translation ...............................62 8.3.1. ValueRange Translation .............................63 8.3.2. InnerTypeConstraints Translation ...................64 9. Translation of Object Classes ..................................65 9.1. DefinedObjectClass Translation ............................65 9.2. ObjectClassDefn Translation ...............................66 9.2.1. TypeFieldSpec Translation ..........................66 9.2.2. FixedTypeValueFieldSpec Translation ................67 9.2.3. FixedTypeValueSetFieldSpec Translation .............69 9.2.4. VariableTypeValueFieldSpec Translation .............70 9.2.5. VariableTypeValueSetFieldSpec Translation ..........71 9.2.6. FieldName Translation ..............................73 9.2.7. ObjectFieldSpec Translation ........................73 9.2.8. ObjectSetFieldSpec Translation .....................74 10. Translation of Objects ........................................75 10.1. DefinedObject Translation ................................75 10.2. ObjectDefn Translation ...................................76 10.3. ObjectFromObject Translation .............................78 11. Translation of Object Sets ....................................78 11.1. DefinedObjectSet Translation .............................79 11.2. ObjectSetElements Translation ............................80 11.2.1. ObjectSetFromObjects Translation .................81 12. Translation of Information From Objects .......................81 13. Translation of Parameterized Definitions ......................82 14. EncodingControlSections Translation ...........................91 15. Security Considerations .......................................92 16. Acknowledgements ..............................................92 17. IANA Considerations ...........................................92 18. References ....................................................92 18.1. Normative References .....................................92 18.2. Informative References ...................................94 Appendix A. ASN.1 for ASN.X .......................................95 Appendix B. ASN.X for ASN.X ......................................115 1. Introduction Legg Expires 22 June 2007 [Page 3] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 A full parser for the Abstract Syntax Notation One (ASN.1) language [X.680] is difficult to implement due to numerous ambiguities in the notation. For example, certain notations for a Value are syntactically indistinguishable from notation for a ValueSet, Object, ObjectSet, DummyReference or SimpleTableConstraint. An ObjectClassAssignment, ObjectAssignment or ObjectSetAssignment resembles respectively a TypeAssignment, ValueAssignment or ValueSetTypeAssignment. A FixedTypeValueFieldSpec or FixedTypeValueSetFieldSpec resembles respectively an ObjectFieldSpec or ObjectSetFieldSpec, and an ObjectClassFieldType resembles InformationFromObjects notation. In general, such ambiguities can only be resolved once the entire specification has been parsed. There are other notations that are not mutually ambiguous but still require several lexical tokens to be scanned before they can be distinguished from each other. The difficulty of parsing ASN.1 is an impediment to its wider adoption. This document defines a semantically equivalent Extensible Markup Language (XML) [XML10][XML11] representation for ASN.1 specifications called Abstract Syntax Notation X (ASN.X). An ASN.X module is a well-formed and valid XML document conforming to XML namespaces [XMLNS10][XMLNS11]. ASN.X completely avoids the inherent ambiguities of the ASN.1 language, therefore specifications written in ASN.X are much easier to parse and manage than original ASN.1 specifications. For example, any conformant XML processor forms the basis of an ASN.1 toolkit. ASN.X, together with the Robust XML Encoding Rules (RXER) [RXER], constitutes a schema language for XML documents that offers, through other ASN.1 encoding rules, alternative compact binary encodings for XML instance documents conforming to an ASN.X specification. ASN.X definitions can also incorporate type, element and attribute definitions from XML Schema [XSD1] documents, RELAX NG [RNG] documents or Document Type Definitions (DTDs) [XML10][XML11]. ASN.X is defined in terms of rules for translating from an ASN.1 specification. This does not preclude an ASN.X module being written directly without a pre-existing ASN.1 module, however such an ASN.X module is considered valid if and only if there exists, in principle, an ASN.1 module that when translated would yield the ASN.X module. The format for ASN.X has also been designed so that the content of an ASN.X module conforms to the RXER encoding of an abstract value of an ASN.1 type, the ModuleDefinition type, presented in Appendix A. This means that it is possible to decode an ASN.X module using an RXER decoder and then re-encode the abstract value (for storage or transmission) using any of the other encoding rules for ASN.1. Thus the "X" in ASN.X can be regarded as standing for either XML or RXER, Legg Expires 22 June 2007 [Page 4] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 or more generally, for any set of ASN.1 encoding rules. The ASN.X translation of the ASN.1 module in Appendix A is presented in Appendix B. 2. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED" and "MAY" in this document are to be interpreted as described in BCP 14, RFC 2119 [BCP14]. The key word "OPTIONAL" is exclusively used with its ASN.1 meaning. Throughout this document "type" shall be taken to mean an ASN.1 type, and "value" shall be taken to mean an ASN.1 abstract value. A reference to an ASN.1 production [X.680] (e.g., Type, NamedType) is a reference to the text in an ASN.1 specification corresponding to that production. The description of the translation of an ASN.1 module into an ASN.X module makes use of definitions from the XML Information Set (Infoset) [INFOSET]. In particular, information item property names follow the Infoset convention of being shown in square brackets, e.g., [local name]. Literal values of Infoset properties are enclosed in double quotes, however the double quotes are not part of the property values. In the sections that follow, "information item" will be abbreviated to "item", e.g., "element information item" is abbreviated to "element item". Element items will be referred to by their [local name] in angle brackets, e.g., "the element item" means the element item with the [local name] "type". Attribute items will be referred to by their [local name], e.g., "the type attribute item" means the attribute item with the [local name] "type". This document uses the namespace prefix "asnx:" to stand for the namespace name "urn:ietf:params:xml:ns:asnx", though in practice any valid namespace prefix is permitted in ASN.X. Encoding instructions [X.680-1] referenced by name in this specification are encoding instructions for RXER [RXEREI]. The associated provisions do not apply to encoding instructions for other encoding rules that happen to have the same name. Code points for characters [UNICODE] are expressed using the Unicode convention U+n, where n is four to six hexadecimal digits, e.g., the space character is U+0020. 3. General Considerations Legg Expires 22 June 2007 [Page 5] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 ASN.X is defined in terms of rules for translating an ASN.1 module into a synthetic Infoset. This synthetic Infoset is then serialized into a well-formed and valid XML document (the ASN.X module) in the same manner that the synthetic Infoset for a non-canonical RXER encoding is serialized into an XML document (see Section 6.12 of the specification for RXER [RXER]). Aside: The serialization permits CDATA sections, character references and parsed entity references. However, note that an ASN.X module may be transferred as data in a protocol and that some protocols disallow entity references. Apart from the [document element] of the document item for an ASN.X module, the translation of some ASN.1 construct belongs to the [children] or [attributes] of an enclosing element item. Where the translation of the construct is an element item, it is appended to the [children] of the enclosing element item. Elements MUST be appended to the [children] of the enclosing element item in the order described. Translators MAY add white space character items (i.e., U+0020, U+0009, U+000D and U+000A) to the [children] of any element item (to improve the layout) except element items with the [local name] "literalValue", "fieldName" or "restrictBy". Aside: White space in the [children] of and element items is explicitly covered under their respective descriptions. Where the translation of the construct is an attribute item, it is added to the [attributes] of the enclosing element item. The order of attribute items is not significant. Translators MAY add leading and trailing white space characters to the [normalized value] of any attribute item except an attribute item with the [local name] "literalValue". Aside: An attribute or element item with the [local name] "literalValue" holds an RXER Infoset translation of an abstract value, and white space characters may be significant in that abstract value. In most cases, RXER itself permits optional leading and trailing white space characters in the Infoset translation. Translators MAY add comment and processing instruction (PI) items to the [children] of any element item except an element item with the [local name] "literalValue". Aside: In most cases, RXER itself permits comment and PI items in the [children] of the element items with the [local name] Legg Expires 22 June 2007 [Page 6] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 "literalValue". Aside: Note that an ASN.X module may be transferred as data in a protocol and that some protocols disallow processing instructions. The [in-scope namespaces] and [namespace attributes] for and element items are determined according to Section 6.10 of the specification for RXER [RXER]. The [in-scope namespaces] and [namespace attributes] for other element items in the translation are determined according to Section 6.2.2.1 of the specification for RXER. The [namespace name] of any element item or attribute item generated by the translation from an ASN.1 specification has no value unless specified otherwise. In those cases where the [namespace name] of an element item has a value, the [prefix] of the element item is determined according to Section 6.2.2.2 of the specification for RXER. In those cases where the [namespace name] of an attribute item has a value, the [prefix] of the attribute item is determined according to Section 6.2.3.1 of the specification for RXER. Aside: Non-canonical RXER allows all valid namespace prefixes and all valid placements for their corresponding namespace declaration attributes. Whenever an element item is added to the [children] of an enclosing element item, the enclosing element item becomes the [parent] of the element item. Whenever an attribute item is added to the [attributes] of an element item, the element item becomes the [owner element] of the attribute item. For each attribute item, the [specified] property is set to true, the [attribute type] has no value and the value of the [references] property is set to unknown. 3.1. Annotations In a number of places, as indicated in subsequent sections, the translator is permitted to add an element item with the [local name] "annotation". The [children] and [attributes] of the element item are at the discretion of the translator. Typical uses of the element item would be to hold comments from the ASN.1 specification that are normative in nature, e.g., a comment in a user defined constraint, or to hold directives for an ASN.1 compiler. Free text or XML comments in an element will be Legg Expires 22 June 2007 [Page 7] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 preserved in a Canonical RXER (CRXER) encoding [RXER] (because the corresponding ASN.1 type for the element item is the Markup type [RXER]), while XML comments outside elements will not be preserved. Vendors using the element items to hold ASN.1 compiler directives (as attributes or child elements of the element) SHOULD use element or attribute names that are qualified with a namespace name specific to the vendor. 4. ModuleDefinition Translation The translation of a ModuleDefinition [X.680] (an ASN.1 module) is an element item with the [local name] "module" and the [namespace name] "urn:ietf:params:xml:ns:asnx" (i.e., an element item). The element item is typically the [document element] of a document item. An attribute item with the [local name] "format" and [normalized value] "1.0" MAY be added to the [attributes] of the element item. An ASN.1 module has a schema identity URI if it contains a SCHEMA-IDENTITY encoding instruction, in which case the schema identity URI is the character string specified by the AnyURIValue of the SCHEMA-IDENTITY encoding instruction. If the ASN.1 module being translated has a schema identity URI, then an attribute item with the [local name] "schemaIdentity" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the schema identity URI of the module. If the target namespace [RXEREI] for the ASN.1 module is not absent, then an attribute item with the [local name] "targetNamespace" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the target namespace of the module. Aside: An ASN.1 module has a target namespace if it contains a TARGET-NAMESPACE encoding instruction. If the ASN.1 module contains a TARGET-NAMESPACE encoding instruction that specifies a Prefix, then an attribute item with the [local name] "targetPrefix" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the character string specified by the NCNameValue in the Prefix. Legg Expires 22 June 2007 [Page 8] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 In examples in the remainder of this document the namespace prefix "tns:" is used to stand for the target namespace of the module being translated. An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the modulereference in the ModuleIdentifier in the ModuleDefinition. If the DefinitiveIdentifier in the ModuleIdentifier in the ModuleDefinition is not empty, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the RXER character data translation [RXER] of the DefinitiveIdentifier. If the TagDefault in the ModuleDefinition is empty, then an attribute item with the [local name] "tagDefault" and [normalized value] "explicit" SHALL be added to the [attributes] of the element item. If the TagDefault in the ModuleDefinition is not empty and the first keyword in the TagDefault is not "AUTOMATIC", then an attribute item with the [local name] "tagDefault" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the first keyword in the TagDefault with all letters downcased, i.e., "explicit" or "implicit". If the TagDefault in the ModuleDefinition is not empty and the first keyword in the TagDefault is "AUTOMATIC", then an attribute item with the [local name] "tagDefault" and [normalized value] "automatic" MAY be added to the [attributes] of the element item. If the ExtensionDefault in the ModuleDefinition is not empty, then an attribute item with the [local name] "extensibilityImplied" and [normalized value] "true" or "1" SHALL be added to the [attributes] of the element item. If the ExtensionDefault in the ModuleDefinition is empty, then an attribute item with the [local name] "extensibilityImplied" and [normalized value] "false" or "0" MAY be added to the [attributes] of the element item. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of each Assignment in the AssignmentList in the ModuleBody in the ModuleDefinition of the module being translated Legg Expires 22 June 2007 [Page 9] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 SHALL be appended to the [children] of the element item. If the EncodingControlSections instance in the ModuleDefinition contains an EncodingControlSection for RXER, then the translation of each NamedType in a TopLevelComponent [RXEREI] nested in the EncodingInstructionAssignmentList SHALL be added to the [children] of the element item. The relative order of the top-level components [RXEREI] SHOULD be preserved in the translation, however the translations of the top-level components MAY be interspersed with the translations of the assignments in the AssignmentList. The translation of the EncodingControlSections instance in the ModuleDefinition of the module being translated SHALL be appended to the [children] of the element item. Example MyModule DEFINITIONS IMPLICIT TAGS EXTENSIBILITY IMPLIED ::= BEGIN MyType ::= INTEGER ENCODING-CONTROL RXER SCHEMA-IDENTITY "http://example.com/id/MyModule" TARGET-NAMESPACE "http://example.com/ns/MyModule" COMPONENT myElement INTEGER END 5. Translation of Assignments Legg Expires 22 June 2007 [Page 10] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 5.1. Referencing Named Constructs An Assignment in ASN.1 associates a reference name with a Type, Value, ValueSet, ObjectClass, Object or ObjectSet. For ASN.X, an Assignment is also regarded as associating an expanded name [XMLNS10][XMLNS11] with the Type, Value, ValueSet, ObjectClass, Object or ObjectSet. ASN.X uses these expanded names, rendered as qualified names [XMLNS10][XMLNS11], in place of the references in an ASN.1 specification. In every case, the local name of the expanded name is the typereference, valuereference, objectclassreference, objectreference or objectsetreference in the Assignment (i.e., the [normalized value] of the name attribute item in the translation of the Assignment, ignoring white space characters). If the target namespace of the ASN.1 module in which the Assignment is defined is not absent, then the namespace name of the expanded name is that target namespace, otherwise the namespace name of the expanded name has no value. When the expanded name is rendered as a qualified name, the namespace prefix is determined according to Section 6.7.11.1 of the specification for RXER [RXER]. If an ASN.1 specification contains two or more modules where the target namespace is absent, then there exists the possibility that the expanded names defined by the ASN.X translations of those modules are not distinct. The expanded names are not distinct if: (1) two or more type or value set assignments define the same typereference, or (2) two or more value assignments define the same valuereference, or (3) two or more object class assignments define the same objectclassreference, or (4) two or more object assignments define the same objectreference, or (5) two or more object set assignments define the same objectsetreference, or (6) two or more top-level element components [RXEREI] have the same local name, or (7) two or more top-level attribute components [RXEREI] have the same local name. If the expanded names are not distinct, then an unambiguous Legg Expires 22 June 2007 [Page 11] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 translation into ASN.X does not exist unless each of the modules has a SCHEMA-IDENTITY encoding instruction. Consequently, if two or more modules where the target namespace is absent are being translated into ASN.X and the reference names defined in those modules will not be distinct, then as a local action prior to the translation, a SCHEMA-IDENTITY encoding instruction MUST be added to each of the modules that defines one or more of the indistinct expanded names and that does not already have a SCHEMA-IDENTITY encoding instruction. The character string (a URI) specified by the AnyURIValue of each added SCHEMA-IDENTITY encoding instruction is freely chosen by the translator, subject to the condition that these character strings are distinct [RXEREI]. Aside: Although this means that different translators might produce ASN.X modules that are syntactically different for any given ASN.1 module, those ASN.X modules will be semantically equivalent to each other and to the original ASN.1 module. TARGET-NAMESPACE and SCHEMA-IDENTITY encoding instructions are RECOMMENDED for every ASN.1 module. 5.2. Importing Namespaces An Assignment is referenced from an ASN.X module if its associated expanded name appears as a qualified name in the [normalized value] of an attribute item with the [local name] "type", "value", "class", "object" or "objectSet". These references are categorized as direct references. An Assignment or top-level component is also referenced from an ASN.X module if its expanded name appears as a qualified name in the [normalized value] of an attribute item with the [local name] "ref". This reference is only categorized as direct if the ref attribute is not the result of the translation of a DefinedType subject to a TYPE-REF encoding instruction or a NamedType subject to an ATTRIBUTE-REF or ELEMENT-REF encoding instruction. Aside: In the case of an indirect reference, an attribute item with the [local name] "embedded" and [normalized value] "true" or "1" will also be present. Definition (external module): An external module is any module other than the module being translated and the AdditionalBasicDefinitions module [RXER]. Aside: The AdditionalBasicDefinitions module is always assumed to be imported, as are all the built-in types and object classes of ASN.1. An element item with the [local name] "import" SHALL be added to the Legg Expires 22 June 2007 [Page 12] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [children] of the element item for each external module containing Assignments or top-level components that are directly referenced from the ASN.X module. An element item MAY be added to the [children] of the element item for any other external module. An attribute item with the [local name] "name" SHOULD be added to the [attributes] of the element item. The [normalized value] of this attribute item is the modulereference in the ModuleIdentifier in the ModuleDefinition of the external module. If the DefinitiveIdentifier in the ModuleIdentifier in the ModuleDefinition of the external module is not empty, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the RXER character data translation of the DefinitiveIdentifier. If the external module has a schema identity URI, then an attribute item with the [local name] "schemaIdentity" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the schema identity URI of the external module. If the target namespace of the external module is not absent, then an attribute item with the [local name] "namespace" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the target namespace of the external module. An attribute item with the [local name] "schemaLocation" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is a URI [URI] indicating the physical location of the ASN.X translation of the external module. The element items MUST follow an element item (if present) and MUST precede any other element items in the [children] of the element item. Note that because of the way parameterized references are expanded in ASN.X (see Section 13), the modules in the Imports in the ModuleBody in the ModuleDefinition may not correspond exactly to the element items. 5.3. TypeAssignment Translation The translation of a TypeAssignment is an element item with the Legg Expires 22 June 2007 [Page 13] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [local name] "namedType". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the typereference on the left hand side of the assignment. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of the Type on the right hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. Example MyType ::= INTEGER 5.4. ValueAssignment and XMLValueAssignment Translation The translation of a ValueAssignment is an element item with the [local name] "namedValue". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the valuereference on the left hand side of the assignment. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of the Type on the left hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. The translation of the Value on the right hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. Example myValue INTEGER ::= 10 An XMLValueAssignment is converted into the equivalent ValueAssignment and then translated as a ValueAssignment. Note that the ASN.X representation for a Value is unrelated to XMLTypedValue. 5.5. ValueSetTypeAssignment Translation The translation of a ValueSetTypeAssignment is an element item with the [local name] "namedValueSet". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this Legg Expires 22 June 2007 [Page 14] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 attribute item is the typereference on the left hand side of the assignment. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of the Type on the left hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. The translation of the ValueSet on the right hand side of the assignment SHALL be added to the [children] of the element item. Example MyValueSet INTEGER ::= { 10 } 10 5.6. ObjectClassAssignment Translation The translation of an ObjectClassAssignment is an element item with the [local name] "namedClass". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the objectclassreference on the left hand side of the assignment. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of the ObjectClass on the right hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. Example MY-CLASS ::= TYPE-IDENTIFIER 5.7. ObjectAssignment Translation The translation of an ObjectAssignment is an element item with the [local name] "namedObject". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the Legg Expires 22 June 2007 [Page 15] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 objectreference on the left hand side of the assignment. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of the DefinedObjectClass on the left hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. The translation of the Object on the right hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. Example myObject TYPE-IDENTIFIER ::= { NULL IDENTIFIED BY { 1 3 14 3 2 26 } } 5.8. ObjectSetAssignment Translation The translation of an ObjectSetAssignment is an element item with the [local name] "namedObjectSet". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the objectsetreference on the left hand side of the assignment. An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of the DefinedObjectClass on the left hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. The translation of the ObjectSet on the right hand side of the assignment SHALL be added to the [children] or [attributes] of the element item. Example MyObjectSet TYPE-IDENTIFIER ::= { myObject } Legg Expires 22 June 2007 [Page 16] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 5.9. ParameterizedAssignment Translation The translation of an ASN.1 specification into ASN.X replaces any reference to a parameterized definition [X.683] with the definition expanded in-line. Consequently, there is no direct translation for a ParameterizedAssignment, though its definition may come into play in the translation of references to the parameterized definition (see Section 13). 6. Translation of Types The rules for translating the different varieties of Type are detailed in this section. Note that the notation of ASN.1 is ambiguous where a Type is both prefixed [X.680-1] (e.g., tagged) and constrained. For example, the notation "[0] INTEGER (0..10)" could be interpreted as either a tagged ConstrainedType or a constrained TaggedType. For the purposes of the translation into ASN.X, the constraint is assumed to have higher precedence than the prefix, so the above notation would be taken to be a tagged ConstrainedType. 6.1. Identifier Replacement Various RXER encoding instructions can be used to override an identifier in an ASN.1 specification with an NCName [XMLNS10]. The NCName is given pre-eminence in the ASN.X representation and the identifier is not explicitly given if it is algorithmically related to the NCName. The cases where an NCName overrides an identifier are covered individually in other parts of this specification and make use of the following definition. Definition (reduction): The reduction of an NCName is the string of characters resulting from the following operations performed in order on the NCName: (1) replace each full stop ('.', U+002E) and low line ('_', U+005F) character with a hyphen character ('-', U+002D), (2) remove every character except latin letters (U+0041-U+005A, U+0061-U+007A), decimal digits (U+0030-U+0039) and hyphens (U+002D), (3) remove leading and trailing hyphen characters, (4) replace sequences of two or more hyphen characters with a single hyphen, and Legg Expires 22 June 2007 [Page 17] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 (5) convert the first character to lowercase if it is an uppercase letter. Aside: If the reduction of an NCName is not the same as the identifier that the NCName replaces, then the identifier will be explicitly given in the translation into ASN.X. 6.2. DefinedType Translation If a Type is a DefinedType in a ReferencedType, then the translation of the Type is the translation of the DefinedType. If a DefinedType is not a ParameterizedType, ParameterizedValueSetType or DummyReference and is not subject to a TYPE-REF or REF-AS-TYPE encoding instruction, then the translation of the DefinedType is either the attribute form translation of a type reference, or the element form translation of a type reference. The attribute form translation of a type reference is an attribute item with the [local name] "type". The [normalized value] of this attribute item is a qualified name for the expanded name of the referenced type definition (see Section 5.1). The attribute form translation SHALL NOT be used if this expanded name is not distinct with respect to the current module and the modules referenced by its element items (see Section 5.1). The element form translation of a type reference is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An attribute item with the [local name] "ref" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is a qualified name for the expanded name of the referenced type definition. If this expanded name is not distinct with respect to the current module and the modules referenced by its element items, then an attribute item with the [local name] "context" SHALL be added to the [attributes] of the element item, otherwise if the module containing the referenced type definition has a schema identity URI, then an attribute item with the [local name] "context" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is the schema identity URI of the module containing the type definition referenced by the DefinedType. Aside: If a reference name is not distinct, then the module containing the referenced definition must have a schema identity URI (see Section 5.1). Legg Expires 22 June 2007 [Page 18] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 An attribute item with the [local name] "embedded" and [normalized value] "false" or "0" MAY be added to the [attributes] of the element item. The translation of the DefinedType is the same whether the type definition is referenced by a typereference or an ExternalTypeReference. If a DefinedType is subject to a TYPE-REF encoding instruction, then the translation of the DefinedType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An attribute item with the [local name] "ref" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the RXER character data translation of the QNameValue in the TYPE-REF encoding instruction. If a ContextParameter is present in the RefParameters in the TYPE-REF encoding instruction, then an attribute item with the [local name] "context" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the string value of the AnyURIValue in the ContextParameter. An attribute item with the [local name] "embedded" and [normalized value] "true" or "1" SHALL be added to the [attributes] of the element item. Aside: The embedded attribute item indicates whether a type is directly referenced as a DefinedType or indirectly referenced through a TYPE-REF encoding instruction. An ASN.1 type can be referenced either way. Type definitions in other schema languages cannot be directly referenced. If a DefinedType is subject to a REF-AS-TYPE encoding instruction, then the translation of the DefinedType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An attribute item with the [local name] "elementType" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the RXER character data translation of the NameValue in the REF-AS-TYPE encoding instruction. If a ContextParameter is present in the RefParameters in the REF-AS-TYPE encoding instruction, then an attribute item with the [local name] "context" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the string value of the AnyURIValue in the ContextParameter. Example CHOICE { one Foo, Legg Expires 22 June 2007 [Page 19] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 two [RXER:TYPE-REF { namespace-name "http://www.example.com/PO1", local-name "PurchaseOrderType" }] Markup, three [RXER:REF-AS-TYPE "product" CONTEXT "http://www.example.com/inventory"] Markup } If a DefinedType is a DummyReference, ParameterizedType or ParameterizedValueSetType, then the translation of the Type is the translation of that DummyReference, ParameterizedType or ParameterizedValueSetType (see Section 13). 6.3. Translation of Built-in Types If a Type is a BuiltinType or ReferencedType that is one of the productions in Table 1 in Section 5 of the specification for RXER [RXER], then the translation of the Type is either the attribute form or element form translation of that type. The attribute form translation of a Type that is a BuiltinType or ReferencedType that is one of the productions in Table 1 is an attribute item with the [local name] "type". The [normalized value] of this attribute item is a qualified name for the expanded name of the built-in type (see Section 5 of the specification for RXER [RXER]). The element form translation of a Type that is a BuiltinType or ReferencedType that is one of the productions in Table 1 is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An attribute item with the [local name] "ref" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is a qualified name for the Legg Expires 22 June 2007 [Page 20] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 expanded name of the built-in type. Example BOOLEAN Usually the translator is free to choose either the attribute form or element form translation for a Type, however in some contexts attribute forms for a Type are explicitly disallowed. 6.4. BitStringType Translation The translation of a BitStringType with a NamedBitList is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "namedBitList" SHALL be appended to the [children] of the element item. The translation of each NamedBit in the NamedBitList SHALL be appended to the [children] of the element item. The translation of a NamedBit is an element item with the [local name] "namedBit". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. If the BitStringType is subject to a VALUES encoding instruction, then the [normalized value] of this attribute item is the replacement name [RXEREI] for the identifier in the NamedBit, otherwise it is the identifier in the NamedBit. If the BitStringType is subject to a VALUES encoding instruction and the reduction of the replacement name (see Section 6.1) is not the same as the identifier, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the element item, otherwise an attribute item with the [local name] "identifier" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is the identifier in the NamedBit. An attribute item with the [local name] "bit" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the digit string representation of the integer value of the number or DefinedValue in the NamedBit. Examples BIT STRING { zero(0), one(1), two(2) } Legg Expires 22 June 2007 [Page 21] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [RXER:VALUES ALL CAPITALIZED, wednesday AS "Midweek"] BIT STRING { monday(0), tuesday(1), wednesday(2), thursday(3), friday(4) } 6.5. IntegerType Translation The translation of an IntegerType with a NamedNumberList is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "namedNumberList" SHALL be appended to the [children] of the element item. The translation of each NamedNumber in the NamedNumberList SHALL be appended to the [children] of the element item. The translation of a NamedNumber is an element item with the [local name] "namedNumber". An attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. If the IntegerType is subject to a VALUES encoding instruction, then the [normalized value] of this attribute item is the replacement name [RXEREI] for the identifier in the NamedNumber, otherwise it is the identifier in the NamedNumber. If the IntegerType is subject to a VALUES encoding instruction and the reduction of the replacement name (see Section 6.1) is not the same as the identifier, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the element item, otherwise an attribute item with the [local name] "identifier" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is the Legg Expires 22 June 2007 [Page 22] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 identifier in the NamedNumber. An attribute item with the [local name] "number" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the digit string representation of the integer value of the SignedNumber or DefinedValue in the NamedNumber. Examples INTEGER { nothing(0), a-little(1), a-lot(100) } [RXER:VALUES ALL CAPITALIZED, very-high AS "DANGEROUS"] INTEGER { low(25), medium(50), high(75), very-high(100) } 6.6. EnumeratedType Translation The translation of an EnumeratedType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "enumerated" SHALL be appended to the [children] of the element item. The translation of each EnumerationItem nested in the RootEnumeration in the Enumerations instance in the EnumeratedType SHALL be appended to the [children] of the element item. If an ellipsis ("...") is present in the Enumerations instance, then an element item with the [local name] "extension" SHALL be appended to the [children] of the element item and the translation of the ExceptionSpec (possibly empty) SHALL be added to the [children] of the element item. If an AdditionalEnumeration is present in the Enumerations instance, then Legg Expires 22 June 2007 [Page 23] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 the translation of each EnumerationItem nested in the AdditionalEnumeration SHALL be appended to the [children] of the element item. The translation of an EnumerationItem is an element item with the [local name] "enumeration". If the EnumerationItem is of the "identifier" form, then an attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. If the EnumeratedType is subject to a VALUES encoding instruction, then the [normalized value] of this attribute item is the replacement name [RXEREI] for the identifier, otherwise it is the identifier. If the EnumeratedType is subject to a VALUES encoding instruction and the reduction of the replacement name (see Section 6.1) is not the same as the identifier, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the element item, otherwise an attribute item with the [local name] "identifier" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is the identifier. If the EnumerationItem is of the "NamedNumber" form, then an attribute item with the [local name] "name" SHALL be added to the [attributes] of the element item. If the EnumeratedType is subject to a VALUES encoding instruction, then the [normalized value] of this attribute item is the replacement name [RXEREI] for the identifier in the NamedNumber, otherwise it is the identifier in the NamedNumber. If the EnumeratedType is subject to a VALUES encoding instruction and the reduction of the replacement name is not the same as the identifier, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the element item, otherwise an attribute item with the [local name] "identifier" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is the identifier in the NamedNumber. An attribute item with the [local name] "number" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the digit string representation of the integer value of the SignedNumber or DefinedValue in the NamedNumber. Examples ENUMERATED { red(0), green(1), ..., blue(2) } Legg Expires 22 June 2007 [Page 24] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [RXER:VALUES ALL CAPITALIZED, red AS "Crimson"] ENUMERATED { red, yellow, green, blue } 6.7. PrefixedType Translation The translation of a PrefixedType [X.680-1] that is a TaggedType is either the short form translation (Section 6.7.1) or long form translation (Section 6.7.2) of the TaggedType. Aside: The short form translation is provided because TaggedType notation is heavily used in existing ASN.1 specifications. The long form translation has the same structure as the translation of an EncodingPrefixedType and can be simplified where there is a series of nested PrefixedType instances. If a PrefixedType is an EncodingPrefixedType and the EncodingReference is RXER, or the EncodingReference is empty and the default encoding reference [X.680-1] for the module is RXER, then the translation of the PrefixedType is the translation of the Type in the EncodingPrefixedType. Aside: This is not suggesting that RXER encoding instructions are ignored. Encoding instructions for RXER are not explicitly represented in ASN.X, but rather affect how an ASN.1 module is translated into an ASN.X module (since the content of an ASN.X module is also the RXER encoding of an abstract value of the ModuleDefinition ASN.1 type in Appendix A). The individual effects of RXER encoding instructions on the translation are addressed in other parts of this specification. Encoding instructions for other encoding rules have explicit representations in ASN.X. If a PrefixedType is an EncodingPrefixedType and the Legg Expires 22 June 2007 [Page 25] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 EncodingReference is not RXER, or the EncodingReference is empty and the default encoding reference for the module is not RXER, then the translation of the PrefixedType is an element item with the [local name] "prefixed". The translation of the EncodingPrefix in the EncodingPrefixedType SHALL be added to the [children] of the element item. If the EncodingReference of an EncodingPrefix is not empty, then the translation of the EncodingPrefix is an element item with the encodingreference in the EncodingReference as the [local name]. The translation of the EncodingInstruction in the EncodingPrefix SHALL be added to the [children] of this element item. If the EncodingReference of an EncodingPrefix is empty, then the translation of the EncodingPrefix is an element item with the default encoding reference for the module as the [local name]. The translation of the EncodingInstruction in the EncodingPrefix SHALL be added to the [children] of this element item. The EncodingInstruction notation is different for each set of encoding instructions, and their translations into ASN.X are specified in separate documents [GSEREIT][XEREIT]. At the time of writing, only three sets of encoding instructions have been defined (for RXER [RXEREI], GSER [GSEREI] and EXTENDED-XER [X.693-1]). If the child element item of a element item has no attribute items and has a child element item, then that child element item MAY be replaced by the [children] and [attributes] of the inner element item. Note that the long form translation of a TaggedType is also eligible for this rewriting step. This rewriting step MAY be applied to the result of a previous rewriting step if the necessary condition still holds. Example These three definitions are equivalent. [XER:ATTRIBUTE] [XER:USE-UNION] [GSER:CHOICE-OF-STRINGS] CHOICE { one PrintableString, two UTF8String } Legg Expires 22 June 2007 [Page 26] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.7.1. Short Form TaggedType Translation The short form translation of a TaggedType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "tagged" SHALL be appended to the [children] of the element item. If the Class in the Tag in the TaggedType is not empty, then an attribute item with the [local name] "tagClass" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the Class of the Tag with all letters downcased, i.e., either "universal", "application" or "private". An attribute item with the [local name] "number" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the digit string representation of the integer value of the number or DefinedValue in Legg Expires 22 June 2007 [Page 27] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 the ClassNumber in the Tag. If the Tag is immediately followed by the "IMPLICIT" keyword, then an attribute item with the [local name] "tagging" and [normalized value] "implicit" SHALL be added to the [attributes] of the element item. If the Tag is immediately followed by the "EXPLICIT" keyword, then an attribute item with the [local name] "tagging" and [normalized value] "explicit" SHALL be added to the [attributes] of the element item. The translation of the Type in the TaggedType SHALL be added to the [children] or [attributes] of the element item. Examples [0] INTEGER [APPLICATION 10] IMPLICIT BOOLEAN 6.7.2. Long Form TaggedType Translation The long form translation of a TaggedType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "prefixed" SHALL be appended to the [children] of the element item. The translation of the Tag in the TaggedType SHALL be added to the [children] of the element item. The translation of a Tag is an element item with the [local name] "TAG". If the Class of the Tag is not empty, then an attribute item with the [local name] "tagClass" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the Class of the Tag with all letters downcased, i.e., either "universal", "application" or "private". Legg Expires 22 June 2007 [Page 28] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 An attribute item with the [local name] "number" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the digit string representation of the integer value of the number or DefinedValue in the ClassNumber in the Tag. If the Tag is immediately followed by the "IMPLICIT" keyword, then an attribute item with the [local name] "tagging" and [normalized value] "implicit" SHALL be added to the [attributes] of the element item. If the Tag is immediately followed by the "EXPLICIT" keyword, then an attribute item with the [local name] "tagging" and [normalized value] "explicit" SHALL be added to the [attributes] of the element item. The translation of the Type in the TaggedType SHALL be added to the [children] or [attributes] of the element item. Examples [0] INTEGER [APPLICATION 10] IMPLICIT BOOLEAN 6.8. SelectionType Translation The translation of a SelectionType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "selection" SHALL be appended to the [children] of the element item. The identifier in a SelectionType identifies a NamedType in the definition of the Type in the SelectionType. The translation of that NamedType will be an element item with the [local name] either Legg Expires 22 June 2007 [Page 29] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 "attribute", "element", "component", "group" or "member". An attribute item with the same [local name] as the translation of the NamedType SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is a qualified name for the expanded name of the NamedType [RXEREI]. The translation of the Type in the SelectionType SHALL be added to the [children] or [attributes] of the element item. Examples field1 < MyChoiceType field2 < CHOICE { field2 [RXER:ATTRIBUTE][RXER:NAME AS "field-two"] INTEGER } 6.9. InstanceOfType Translation The translation of an InstanceOfType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "instanceOf" SHALL be appended to the [children] of the element item. The translation of the DefinedObjectClass in the InstanceOfType SHALL be added to the [children] or [attributes] of the element item. Example INSTANCE OF TYPE-IDENTIFIER Legg Expires 22 June 2007 [Page 30] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.10. ObjectClassFieldType Translation The translation of an ObjectClassFieldType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "fromClass" SHALL be appended to the [children] of the element item. The translation of the DefinedObjectClass in the ObjectClassFieldType SHALL be added to the [children] or [attributes] of the element item. The translation of the FieldName (see Section 9.2.6) in the ObjectClassFieldType SHALL be added to the [children] or [attributes] of the element item. Example OPERATION.&Linked.&ArgumentType 6.11. TypeFromObject and ValueSetFromObjects Translation The translation of a TypeFromObject or ValueSetFromObjects is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "fromObjects" SHALL be appended to the [children] of the element item. The translation of the ReferencedObjects instance in the TypeFromObject or ValueSetFromObjects SHALL be added to the [children] or [attributes] of the element item. The translation of the FieldName in the TypeFromObject or ValueSetFromObjects SHALL be added to the [children] or [attributes] of the element item. Example invertMatrix.&Errors.&errorCode 6.12. Translation of Combining Types This section details the translation of the ASN.1 combining types: SET, SEQUENCE, CHOICE, SET OF and SEQUENCE OF. The combining type definitions all make use of the NamedType notation. 6.12.1. NamedType Translation A NamedType is translated in one of three ways depending on the context. These are the normal translation, the member translation and the item translation. These translations are not interchangeable. One of the three will be explicitly invoked as part of the translation of an enclosing combining type. The normal translation of a NamedType is an element item with the [local name] determined as follows: (1) if the NamedType is subject to an ATTRIBUTE or ATTRIBUTE-REF encoding instruction, or subject to a COMPONENT-REF encoding instruction that references a top-level NamedType that is subject to an ATTRIBUTE encoding instruction, then the [local name] is "attribute", (2) otherwise, if the NamedType is subject to a GROUP encoding instruction, then the [local name] is "group", (3) otherwise, if the NamedType is subject to a SIMPLE-CONTENT encoding instruction, then the [local name] is "simpleContent", (4) otherwise, the [local name] is "element" or "component" (translator's choice). Aside: The local names "element" and "component" are synonymous. The "component" alternative is offered for specifying applications that don't use RXER (except for the ASN.X specification itself, of course), where referring to parts of an encoding as elements would seem incongruous. The member translation of a NamedType is an element item with the [local name] "member". The item translation of a NamedType is an element item with the [local name] "item". Aside: A Namedtype for which the member or item translation is Legg Expires 22 June 2007 [Page 32] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 invoked will never be subject to an ATTRIBUTE, ATTRIBUTE-REF, COMPONENT-REF, GROUP, SIMPLE-CONTENT or TYPE-AS-VERSION encoding instruction. These encoding instructions are also mutually exclusive [RXEREI]. An element item with the [local name] "annotation" MAY be added to the [children] of the , , , , , or element item. If a NamedType is subject to a TYPE-AS-VERSION encoding instruction, then an attribute item with the [local name] "typeAsVersion" and [normalized value] "true" or "1" SHALL be added to the or element item. For the normal translation, if a NamedType is not subject to an ATTRIBUTE, ATTRIBUTE-REF, COMPONENT-REF, GROUP, SIMPLE-CONTENT or TYPE-AS-VERSION encoding instruction, then an attribute item with the [local name] "typeAsVersion" and [normalized value] "false" or "0" MAY be added to the or element item. For the normal, member and item translations, if a NamedType is not subject to an ATTRIBUTE-REF, COMPONENT-REF, ELEMENT-REF or REF-AS-ELEMENT encoding instruction, then an attribute item with the [local name] "name" SHALL be added to the [attributes] of the , , , , , or element item. The [normalized value] of this attribute item is the local name of the expanded name of the NamedType [RXEREI]. Aside: If there are no NAME, ATTRIBUTE-REF, COMPONENT_REF, ELEMENT-REF or REF-AS-ELEMENT encoding instructions, then the local name of the expanded name of a NamedType is the same as the identifier in the NamedType. If the reduction of the local name (an NCName) of the expanded name of a NamedType is not the same as the identifier in the NamedType, then an attribute item with the [local name] "identifier" SHALL be added to the [attributes] of the , , , , , or element item, otherwise an attribute item with the [local name] "identifier" MAY be added to the [attributes] of the aforementioned element item. The [normalized value] of this attribute item is the identifier in the NamedType. Aside: The identifier attribute is not contingent on there being a name attribute. That is, an element item can have an identifier attribute item without having a name attribute item. If a NamedType is subject to a COMPONENT-REF encoding instruction, Legg Expires 22 June 2007 [Page 33] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 then an attribute item with the [local name] "ref" SHALL be added to the [attributes] of the , or element item. The [normalized value] of this attribute item is a qualified name for the expanded name of the top-level NamedType referenced by the encoding instruction. If the expanded name is not distinct with respect to the current module and the modules referenced by its element items (see Section 5.1), then an attribute item with the [local name] "context" SHALL be added to the [attributes] of the , or element item, otherwise if the module containing the referenced top-level NamedType has a schema identity URI, then an attribute item with the [local name] "context" MAY be added to the [attributes] of the , or element item. The [normalized value] of this attribute item is the schema identity URI of the module containing the referenced top-level NamedType. Aside: If an expanded name is not distinct, then the module containing the referenced top-level NamedType must have a schema identity URI (see Section 5.1). If a NamedType is subject to a COMPONENT-REF encoding instruction, then an attribute item with the [local name] "embedded" and [normalized value] "false" or "0" MAY be added to the [attributes] of the , or element item. If a NamedType is subject to an ATTRIBUTE-REF or ELEMENT-REF encoding instruction, then an attribute item with the [local name] "ref" SHALL be added to the [attributes] of the , or element item. The [normalized value] of this attribute item is the RXER character data translation of the QNameValue in the encoding instruction. An attribute item with the [local name] "embedded" and [normalized value] "true" or "1" SHALL be added to the [attributes] of the , or element item. If a NamedType is subject to a REF-AS-ELEMENT encoding instruction, then an attribute item with the [local name] "elementType" SHALL be added to the [attributes] of the or element item. The [normalized value] of this attribute item is the RXER character data translation of the NameValue in the REF-AS-ELEMENT encoding instruction. If a Namespace is present in the REF-AS-ELEMENT encoding instruction, then an attribute item with the [local name] "namespace" SHALL be added to the [attributes] of the or element item. The [normalized value] of this attribute item is the string value of the AnyURIValue in the Namespace. If a ContextParameter is present in the RefParameters in the Legg Expires 22 June 2007 [Page 34] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 ATTRIBUTE-REF, ELEMENT-REF or REF-AS-ELEMENT encoding instruction, then an attribute item with the [local name] "context" SHALL be added to the [attributes] of the , or element item. The [normalized value] of this attribute item is the string value of the AnyURIValue in the ContextParameter. If a NamedType is subject to both an ATTRIBUTE encoding instruction and a VERSION-INDICATOR encoding instruction, then an attribute item with the [local name] "versionIndicator" and [normalized value] "true" or "1" SHALL be added to the element item. If a NamedType is subject to an ATTRIBUTE encoding instruction and not subject to a VERSION-INDICATOR encoding instruction, then an attribute item with the [local name] "versionIndicator" and [normalized value] "false" or "0" MAY be added to the element item. If a NamedType is not subject to an ATTRIBUTE-REF, COMPONENT-REF, ELEMENT-REF or REF-AS-ELEMENT encoding instruction, then the translation of the Type in the NamedType SHALL be added to the [children] or [attributes] of the , , , , , or element item. If a NamedType is subject to an ATTRIBUTE-REF, COMPONENT-REF, ELEMENT-REF or REF-AS-ELEMENT encoding instruction, then the translation of each EncodingPrefix (Section 6.7) and Tag (Section 6.7.2) textually within the NamedType SHALL be added in order to the [children] of the , or element item. Example CHOICE { one INTEGER, two [RXER:ATTRIBUTE] BOOLEAN, three [RXER:ATTRIBUTE-REF { namespace-name "http://www.example.com/schema", local-name "foo" }] UTF8String, bar [RXER:ELEMENT-REF { namespace-name "http://www.example.com/schema", local-name "bar" }] Markup, five [0] [RXER:REF-AS-ELEMENT "product" CONTEXT "http://www.example.com/inventory"] Markup, six [RXER:GROUP] MySequence } Legg Expires 22 June 2007 [Page 35] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.12.2. SequenceType Translation The translation of a SequenceType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "sequence" SHALL be appended to the [children] of the element item. The translation of each ComponentType nested in the ComponentTypeList in the initial RootComponentTypeList, if present, SHALL be appended to the [children] of the element item. If an ExtensionAndException is present, then an element item with the [local name] "extension" SHALL be appended to the [children] of the element item. If an ExceptionSpec is present in the ExtensionAndException, then the translation of the ExceptionSpec (possibly empty) SHALL be added to the [children] of the element item. If an ExtensionAdditions instance is present, then the translation of each ExtensionAdditionGroup or ComponentType nested in the ExtensionAdditions (if any) SHALL be appended to the [children] of the element item. If an ExtensionEndMarker is present, then the translation of each ComponentType nested in the ComponentTypeList in the final RootComponentTypeList SHALL be appended to the [children] of the element item. The translation of an ExtensionAdditionGroup is an element item with the [local name] "extensionGroup". If the VersionNumber in the ExtensionAdditionGroup is not empty, then an attribute item with the [local name] "version" SHALL be added to the [attributes] of the element item. The [normalized value] of this Legg Expires 22 June 2007 [Page 36] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 attribute item is the number in the VersionNumber. The translation of each ComponentType nested in the ExtensionAdditionGroup SHALL be appended to the [children] of the element item. The translation of a ComponentType of the "NamedType" form is the normal translation of the NamedType. The translation of a ComponentType of the "NamedType OPTIONAL" form is an element item with the [local name] "optional". The normal translation of the NamedType SHALL be added to the [children] of the element item. The translation of a ComponentType of the "NamedType DEFAULT Value" form is an element item with the [local name] "optional". The normal translation of the NamedType SHALL be added to the [children] of the element item. An element item with the [local name] "default" SHALL be appended to the [children] of the element item. The translation of the Value SHALL be added to the [children] or [attributes] of the element item. The translation of a ComponentType of the "COMPONENTS OF Type" form is an element item with the [local name] "componentsOf". The translation of the Type SHALL be added to the [children] or [attributes] of the element item. Example SEQUENCE { one INTEGER, two [RXER:ATTRIBUTE] BOOLEAN OPTIONAL, ..., [[ 2: four NULL ]], COMPONENTS OF MySequence, ..., three PrintableString DEFAULT "third" } Legg Expires 22 June 2007 [Page 37] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.12.3. SetType Translation The translation of a SetType follows the same procedure as the translation of a SequenceType except that SetType replaces SequenceType, "SET" replaces "SEQUENCE", and the [local name] "set" is used instead of "sequence". 6.12.4. ChoiceType Translation The translation of a ChoiceType that is not subject to a UNION encoding instruction is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "choice" SHALL be appended to the [children] of the element item. The normal translation of each NamedType nested in the AlternativeTypeList in the RootAlternativeTypeList in the AlternativeTypeLists SHALL be appended to the [children] of the element item. If an ExtensionAndException is present in the AlternativeTypeLists, then an element item with the [local name] "extension" SHALL be appended to the [children] of the element item. If an ExceptionSpec is present in the ExtensionAndException, then the translation of the ExceptionSpec (possibly empty) is added to the [children] of the element item. If an ExtensionAdditionAlternatives instance is present in the AlternativeTypeLists, then the translation of each ExtensionAdditionAlternativesGroup or NamedType (if any) nested in the ExtensionAdditionAlternatives SHALL be appended in order to the [children] of the element item. The normal translation of the NamedType is used. The translation of an ExtensionAdditionAlternativesGroup is an element item with the [local name] "extensionGroup". If the VersionNumber in the ExtensionAdditionAlternativesGroup is not empty, then an attribute item with the [local name] "version" SHALL be added to the [attributes] of the element item. The Legg Expires 22 June 2007 [Page 38] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [normalized value] of this attribute item is the number in the VersionNumber. The normal translation of each NamedType nested in the AlternativeTypeList in the ExtensionAdditionAlternativesGroup SHALL be appended to the [children] of the element item. Example CHOICE { one INTEGER, two [RXER:NAME AS "Two"] BOOLEAN, ..., [[ 2: three NULL ]], four PrintableString, ... } 6.12.5. Translation of UNION Types The translation of a ChoiceType that is subject to a UNION encoding instruction follows the same procedure as the translation of a ChoiceType that is not subject to a UNION encoding instruction except that the [local name] "union" is used instead of "choice", and the member translation of each NamedType is used instead of the normal translation. In addition, if the UNION encoding instruction has a PrecedenceList, then an attribute item with the [local name] "precedence" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is the white space separated list of qualified names for the expanded names of the NamedType instances [RXEREI] corresponding to the identifiers in the PrecedenceList. A white space separator is one or more of the white Legg Expires 22 June 2007 [Page 39] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 space characters. Example [RXER:UNION PRECEDENCE utf8 visible] CHOICE { printable PrintableString, teletex TeletexString, visible [RXER:NAME AS "ascii"] VisibleString, ..., utf8 UTF8String } 6.12.6. SequenceOfType Translation The translation of a SequenceOfType that is not subject to a LIST encoding instruction is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "sequenceOf" SHALL be appended to the [children] of the element item. If the SequenceOfType is of the "SEQUENCE OF NamedType" form, then the normal translation of the NamedType SHALL be added to the [children] of the element item. If the SequenceOfType is of the "SEQUENCE OF Type" form, then an element item with the [local name] "element" or "component" (translator's choice) SHALL be added to the [children] of the element item. An attribute item with the [local name] "name" and [normalized value] "item" SHALL be added to the [attributes] of the or element item. An attribute item with the [local name] "identifier" and empty [normalized value] SHALL be added to the [attributes] of the or element item. The translation of the Type SHALL be added to the [children] or [attributes] of the or element item. Legg Expires 22 June 2007 [Page 40] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 Examples SEQUENCE OF INTEGER SEQUENCE OF counter INTEGER 6.12.7. Translation of LIST Types The translation of a SequenceOfType that is subject to a LIST encoding instruction is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "list" SHALL be appended to the [children] of the element item. The item translation of the NamedType in the SequenceOfType SHALL be added to the [children] of the element item. Aside: A SequenceOfType is necessarily of the "SEQUENCE OF NamedType" form for a LIST encoding instruction. Example [RXER:LIST] SEQUENCE OF number INTEGER 6.12.8. SetOfType Translation The translation of a SetOfType follows the same procedure as the translation of a SequenceOfType except that SetOfType replaces SequenceOfType, "SET" replaces "SEQUENCE", and the [local name] "setOf" is used instead of "sequenceOf". Legg Expires 22 June 2007 [Page 41] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.12.9. Effect of Insertion Encoding Instructions If a Type is subject to a NO-INSERTIONS, HOLLOW-INSERTIONS, SINGULAR-INSERTIONS, UNIFORM-INSERTIONS or MULTIFORM-INSERTIONS encoding instruction, then an attribute item with the [local name] "insertions" SHALL be added to the [attributes] of the , or element item in the [children] of the element item resulting from the translation of the Type. The [normalized value] of this attribute item is "none" in the case of a NO-INSERTIONS encoding instruction, "hollow" in the case of a HOLLOW-INSERTIONS encoding instruction, "singular" in the case of a SINGULAR-INSERTIONS encoding instruction, "uniform" in the case of a UNIFORM-INSERTIONS encoding instruction, and "multiform" in the case of a MULTIFORM-INSERTIONS encoding instruction. Example [NO-INSERTIONS] CHOICE { one [RXER:GROUP] [RXER:SINGULAR-INSERTIONS] CHOICE { two INTEGER, ... }, ... } 6.13. Translation of Constrained Types If a ConstrainedType is of the "Type Constraint" form, then the translation of the ConstrainedType is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "constrained" SHALL be appended to the [children] of the element item. The translation of the Type SHALL be added to the [children] or Legg Expires 22 June 2007 [Page 42] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [attributes] of the element item. The translation of the Constraint SHALL be added to the [children] of the element item. The translation of a ContainedType that is a TypeWithConstraint is the translation of the TypeWithConstraint. Definition (simple endpoint): A LowerEndpoint or UpperEndpoint is a simple endpoint if it is closed and its value is "MIN", "MAX" or a SignedNumber in an IntegerValue in a BuiltinValue in the Value of the endpoint. Definition (simple range SizeConstraint): A SizeConstraint is a simple range if the Constraint in the SizeConstraint contains only a ValueRange (i.e., a ValueRange in a SubtypeElements instance in an Elements instance in a lone IntersectionElements instance in a lone Intersections instance in a Unions instance in an ElementSetSpec in a RootElementSetSpec in an ElementSetSpecs instance without an AdditionalElementSetSpec in a SubtypeConstraint in a ConstraintSpec in the Constraint) and both endpoints are simple. Definition (simple range Constraint): A Constraint is a simple range if contains only a SizeConstraint that is a simple range (i.e., a simple range SizeConstraint in a SubtypeElements instance in an Elements instance in a lone IntersectionElements instance in a lone Intersections instance in a Unions instance in an ElementSetSpec in a RootElementSetSpec in an ElementSetSpecs instance without an AdditionalElementSetSpec in a SubtypeConstraint in a ConstraintSpec in the Constraint). If the Constraint or SizeConstraint in a TypeWithConstraint is a simple range, then the compact translation of the TypeWithConstraint MAY be used, otherwise the full translation of the TypeWithConstraint is used. The compact translation of a TypeWithConstraint is initially the translation of its notional parent type. If the value of the lower endpoint is not "MIN" or "0", then an attribute item with the [local name] "minSize" SHALL be added to the [attributes] of the , or element item resulting from the translation of the parent type. The [normalized value] of this attribute item is the value of the lower endpoint. If the value of the lower endpoint is "MIN" or "0", then an attribute item with the [local name] "minSize" and [normalized value] "0" MAY be added to the [attributes] of the , or element item. If the value of the upper endpoint is not "MAX", then an attribute item with the [local name] "maxSize" SHALL be added to the [attributes] of the , or element item. The Legg Expires 22 June 2007 [Page 43] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 [normalized value] of this attribute item is the value of the upper endpoint. The full translation of a TypeWithConstraint is an element item with the [local name] "type". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the [local name] "constrained" SHALL be appended to the [children] of the element item. The translation of the notional parent type of the TypeWithConstraint SHALL be added to the [children] or [attributes] of the element item. The translation of the Constraint or SizeConstraint in the TypeWithConstraint SHALL be added to the [children] of the element item. Examples SEQUENCE (SIZE(1..MAX)) OF number INTEGER SEQUENCE SIZE(0..10) OF number INTEGER SEQUENCE SIZE(1..limit) OF number INTEGER Legg Expires 22 June 2007 [Page 44] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 6.13.1. Constraint Translation The translation of a Constraint is the translation of the ConstraintSpec in the Constraint followed by the translation of the ExceptionSpec (possibly empty) in the Constraint. The translation of a ConstraintSpec is the translation of the SubtypeConstraint or GeneralConstraint in the ConstraintSpec. The translation of a SubtypeConstraint is the translation of the ElementSetSpecs in the SubtypeConstraint. The translation of a GeneralConstraint is the translation of the UserDefinedConstraint, TableConstraint or ContentsConstraint in the GeneralConstraint. 6.13.2. UserDefinedConstraint Translation The translation of a UserDefinedConstraint is an element item with the [local name] "constrainedBy". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. The translation of each UserDefinedConstraintParameter in the UserDefinedConstraint SHALL be appended to the [children] of the element item. The translation of a UserDefinedConstraintParameter of the "Governor : Value" form is an element item with the [local name] "valueParameter". The translation of the Type in the Governor SHALL be added to the [children] or [attributes] of the element item. The translation of the Value SHALL be added to the [children] or [attributes] of the element item. The translation of a UserDefinedConstraintParameter of the "Governor : ValueSet" form is an element item with the [local name] "valueSetParameter". The translation of the Type in the Governor SHALL be added to the [children] or [attributes] of the element item. The translation of the ValueSet SHALL be added to the [children] of the element item. The translation of a UserDefinedConstraintParameter of the "Governor : Object" form is an element item with the [local name] "objectParameter". The translation of the DefinedObjectClass in the Governor SHALL be added to the [children] or [attributes] of the element item. The translation of the Object SHALL be added to the [children] or [attributes] of the Legg Expires 22 June 2007 [Page 45] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 element item. The translation of a UserDefinedConstraintParameter of the "Governor : ObjectSet" form is an element item with the [local name] "objectSetParameter". The translation of the DefinedObjectClass in the Governor SHALL be added to the [children] or [attributes] of the element item. The translation of the ObjectSet SHALL be added to the [children] or [attributes] of the element item. The translation of a UserDefinedConstraintParameter that is a Type is an element item with the [local name] "typeParameter". The translation of the Type SHALL be added to the [children] or [attributes] of the element item. The translation of a UserDefinedConstraintParameter that is a DefinedObjectClass is an element item with the [local name] "classParameter". The translation of the DefinedObjectClass SHALL be added to the [children] or [attributes] of the element item. Example OCTET STRING (CONSTRAINED BY { -- contains the hash of the value -- MyType:myValue }) contains the hash of the value 6.13.3. TableConstraint Translation The translation of a TableConstraint that is a SimpleTableConstraint is an element item with the [local name] "table". The translation of the ObjectSet in the SimpleTableConstraint SHALL be added to the [children] or [attributes] of the element item. The translation of a TableConstraint that is a ComponentRelationConstraint is an element item with the [local name] "table". The translation of the DefinedObjectSet in the ComponentRelationConstraint SHALL be added to the [children] or [attributes] of the
element item. The translation of each Legg Expires 22 June 2007 [Page 46] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 AtNotation in the ComponentRelationConstraint SHALL be appended to the [children] of the
element item. The translation of an AtNotation is an element item with the [local name] "restrictBy". The [children] property of the element item is set to the sequence of character items for the character string formed by the concatenation of zero, one or more "../" strings, one for each Level in the AtNotation (including the empty one), followed by a solidus ('/', U+002F) separated list of qualified names for the expanded names of the NamedType instances [RXEREI] identified by the identifiers in the ComponentIdList in the AtNotation. If a NamedType is subject to an ATTRIBUTE or ATTRIBUTE-REF encoding instruction, or subject to a COMPONENT-REF encoding instruction that references a top-level NamedType that is subject to an ATTRIBUTE encoding instruction, then the qualified name for the expanded name is prefixed with the commercial at character ('@', U+0040). Leading and/or trailing white space character items MAY be added to the [children] of the element item. White space character items MAY be added immediately before and/or after any character item for the solidus character ('/', U+002F). Examples ERROR.&Type({Errors}{@severity,@...errorId})
severity../../../errorId
 SEQUENCE { id-att [RXER:NAME AS "ID"] [RXER:ATTRIBUTE] TYPE-IDENTIFIER.&id({AllTypes}), value TYPE-IDENTIFIER.&Type({AllTypes}{@id-att}) } Legg Expires 22 June 2007 [Page 47] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006
@ID
 The element item is required to be self-contained [RXER]. Aside: An element item is self-contained if all namespace prefixes used by the element item and its contents are declared within the element item. 6.13.4. ContentsConstraint Translation The translation of a ContentsConstraint is an element item with the [local name] "contents". If the ContentsConstraint is of the "CONTAINING Type" form, then an element item with the [local name] "containing" SHALL be added to the [children] of the element item. The translation of the Type SHALL be added to the [children] or [attributes] of the element item. If the ContentsConstraint is of the "ENCODED BY Value" form, then an element item with the [local name] "encodedBy" SHALL be added to the [children] of the element item. The translation of the Value SHALL be added to the [children] or [attributes] of the element item. If the ContentsConstraint is of the "CONTAINING Type ENCODED BY Value" form, then an element item with Legg Expires 22 June 2007 [Page 48] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 the [local name] "containing" and an element item with the [local name] "encodedBy" SHALL be added to the [children] of the element item. The translation of the Type SHALL be added to the [children] or [attributes] of the element item. The translation of the Value SHALL be added to the [children] or [attributes] of the element item. Example OCTET STRING (CONTAINING MyType ENCODED BY { joint-iso-itu-t asn1(1) basic-encoding(1) }) 6.13.5. ExceptionSpec Translation The translation of an empty ExceptionSpec is empty. The translation of a non-empty ExceptionSpec is an element item with the [local name] "exception". If the ExceptionIdentification in a non-empty ExceptionSpec is a SignedNumber, then the translation of a notional INTEGER Type SHALL be added to the [children] or [attributes] of the element item and the translation of a notional Value of the INTEGER type with the SignedNumber as its IntegerValue SHALL be added to the [children] or [attributes] of the element item. If the ExceptionIdentification in a non-empty ExceptionSpec is a DefinedValue, then the translation of a notional INTEGER Type SHALL be added to the [children] or [attributes] of the element item and the translation of the DefinedValue SHALL be added to the [children] or [attributes] of the element item. If the ExceptionIdentification in a non-empty ExceptionSpec is of the "Type : Value" form, then the translation of the Type SHALL be added to the [children] or [attributes] of the element item and the translation of the Value SHALL be added to the [children] or [attributes] of the element item. Legg Expires 22 June 2007 [Page 49] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 Examples !10 !myValue !PrintableString:"failure" 7. Translation of Values A Value in an ASN.1 specification is a mix of literal values (e.g., numbers and character strings) and notations for referencing defined values. Likewise, the ASN.X translation of a Value is a mix of markup for literal values and markup for referencing notations (notational values). A Value is categorized by the following definitions. Definition (literal value): A Value is a literal value if and only if it is not a notational value. Definition (notational value): A Value is a notational value if and only if: (1) the Value is a BuiltinValue, and (a) the BuiltinValue is a TaggedValue and the Value in the TaggedValue is a notational value, or (b) the BuiltinValue is a SequenceValue or SetValue with a ComponentValueList that contains a NamedValue where the Value in the NamedValue is a notational value and the translation of the corresponding NamedType (from the governing type of the outer Value) is not an or element item, or (c) the BuiltinValue is a ChoiceValue where the Value of the ChoiceValue is a notational value and the translation of the NamedType corresponding to the identifier in the ChoiceValue is not an or element item, or (d) the BuiltinValue is a SequenceOfValue or SetOfValue with a NamedValueList that contains a NamedValue where the Value of Legg Expires 22 June 2007 [Page 50] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 the NamedValue is a notational value and the translation of the corresponding NamedType (from the governing type of the outer Value) is not an or element item, or (2) the Value is a ReferencedValue, and (a) the ReferencedValue is a ValueFromObject, or (b) the ReferencedValue is a DefinedValue, and (i) the DefinedValue is a valuereference (not a DummyReference) or an ExternalValueReference, or (ii) the DefinedValue is a DummyReference or ParameterizedValue and the substitute definition for the DummyReference or ParameterizedValue (see Section 13) is a notational value, or (iii) the DefinedValue is a DummyReference or ParameterizedValue where the translation of the DummyReference or ParameterizedValue will use a fully expanded reference (see Section 13), or (3) the Value is an ObjectClassFieldValue, and (a) the ObjectClassFieldValue is an OpenTypeFieldVal, or (b) the ObjectClassFieldValue is a FixedTypeFieldVal, and (i) the FixedTypeFieldVal is a BuiltinValue that satisfies case (1), or (ii) the FixedTypeFieldVal is a ReferencedValue that satisfies case (2). A literal value that is a BuiltinValue that is a SequenceValue, SetValue, ChoiceValue, SequenceOfValue or SetOfValue MAY be translated as a notational value. Definition (directly nested): A notational value is directly nested (within a literal value) if the innermost enclosing Value is a literal value. 7.1. Translation of Literal Values The translation of a literal value is either the attribute form translation of a literal value, or the element form translation of a Legg Expires 22 June 2007 [Page 51] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 literal value. The attribute form translation of a literal value is an attribute item with the [local name] "literalValue". The [normalized value] of this attribute item is the RXER character data translation [RXER] of the literal value. The attribute form translation of a literal value SHALL NOT be used if: (1) the RXER Infoset translation of the literal value is not a character data translation [RXER] or is a character data translation that contains qualified names [XMLNS10][XMLNS11], or (2) attribute form translations of Value have been explicitly disallowed in the context where the literal value appears, or (3) the literal value has a nested notational value. The element form translation of a literal value is an element item with the [local name] "literalValue". The [children] and [attributes] of the element item are set to the RXER Infoset translation of the literal value, except that a value of the EXTERNAL type (or a subtype thereof) is translated according to the associated type defined in Clause 34.5 of X.680 [X.680]. In addition, where the [children] and [attributes] of an element item in the translation correspond to a directly nested notational value, the translation specified in Section 7.2 MUST be used for the [children] and [attributes] of that element item, and an attribute item with the [local name] "literal", [namespace name] "urn:ietf:params:xml:ns:asnx" and [normalized value] "false" or "0" (i.e., asnx:literal="false") MUST be added to the [attributes] of that element item. Each outermost element item is required to be self-contained [RXER]. Aside: An element item is self-contained if all namespace prefixes used by the element item and its contents are declared within the element item. Aside: A element item nested within another element item is not required to be self-contained. An attribute item with the [local name] "literal", [namespace name] "urn:ietf:params:xml:ns:asnx" and [normalized value] "true" or "1" (i.e., asnx:literal="true") MAY be added to the [attributes] of the element item and/or any nested element item with Legg Expires 22 June 2007 [Page 52] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 content and attributes that correspond to a literal value. Aside: The asnx:literal attribute operates as a switch that indicates whether the content and other attributes of the element containing the attribute are interpreted as ASN.X notation (a notational value) or as an RXER encoding (a literal value). Example zero INTEGER ::= 0 OR 0 From the perspective of an ASN.X module as the RXER encoding of an ASN.1 value (an abstract value of the ModuleDefinition type in Appendix A), the type of the element is the unconstrained Markup type [RXER], not the governing type of the Value according to the ASN.1 specification. This means that the Infoset representation of the element must be preserved in re-encodings of the ASN.X module. Similarly, the type of the literalValue attribute is a UTF8String, not the governing type of the Value according to the ASN.1 specification. This means that the exact characters of the [normalized value] of the attribute must be preserved in re-encodings of the ASN.X module. 7.2. Translation of Notational Values The translation of a notational value is the translation of the BuiltinValue, ReferencedValue or ObjectClassFieldValue in the notational value. The translation of a ReferencedValue is the translation of the DefinedValue or ValueFromObject in the ReferencedValue. The translation for each of these cases is described as creating an element item with the [local name] "value", which is appropriate for a notational value that stands on its own. However, a notational value may also be directly nested within a literal value, in which case the [local name] will be determined according to RXER and the governing ASN.1 type of the enclosing literal value. Legg Expires 22 June 2007 [Page 53] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 Aside: In the latter case, the element item will also have a literal attribute item with the [normalized value] "false" or "0". A notational value that is not directly nested within a literal value MAY instead have the [local name] "literalValue" provided an attribute item with the [local name] "literal", [namespace name] "urn:ietf:params:xml:ns:asnx" and [normalized value] "false" or "0" is added to the [attributes] of the element item. Examples nothing INTEGER ::= zero OR OR integerList SEQUENCE OF number INTEGER ::= { zero, 3, 7 } 3 7 7.2.1. DefinedValue Translation Legg Expires 22 June 2007 [Page 54] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 If a DefinedValue is a valuereference (not a DummyReference) or an ExternalValueReference, then the translation of the DefinedValue is either the attribute form translation of a value reference, or the element form translation of a value reference. The attribute form translation of a value reference is an attribute item with the [local name] "value". The [normalized value] of this attribute item is a qualified name for the expanded name of the referenced value definition (see Section 5.1). The attribute form translation SHALL NOT be used if this expanded name is not distinct with respect to the current module and the modules referenced by its element items (see Section 5.1). The element form translation of a value reference is an element item with the [local name] "value". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An attribute item with the [local name] "ref" SHALL be added to the [attributes] of the element item. The [normalized value] of this attribute item is a qualified name for the expanded name of the referenced value definition. If this expanded name is not distinct with respect to the current module and the modules referenced by its element items, then an attribute item with the [local name] "context" SHALL be added to the [attributes] of the element item, otherwise if the module containing the referenced value definition has a schema identity URI, then an attribute item with the [local name] "context" MAY be added to the [attributes] of the element item. The [normalized value] of this attribute item is the schema identity URI of the module containing the value definition referenced by the DefinedValue. Aside: If a reference name is not distinct, then the module containing the referenced definition must have a schema identity URI (see Section 5.1). Usually the translator is free to choose either an attribute form or element form translation for a DefinedValue, however in some contexts attribute forms of Value are explicitly disallowed. In particular, the attribute form translation SHALL NOT be used for a DefinedValue in a ReferencedValue in a Value that is directly nested in a literal value. If a DefinedValue is a DummyReference or ParameterizedValue, then the translation of the DefinedValue is the translation of that DummyReference or ParameterizedValue (see Section 13). 7.2.2. BuiltinValue Translation Legg Expires 22 June 2007 [Page 55] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 The translation of a BuiltinValue is the translation of the ChoiceValue, SequenceValue, SetValue, SequenceOfValue, SetOfValue or TaggedValue in the BuiltinValue. Aside: There are other possibilities for a BuiltinValue, but these will all be literal values. This section applies to a BuiltinValue that is a notational value. The translation of a TaggedValue is the translation of the Value in the TaggedValue (which is necessarily a notational value). The translation of a ChoiceValue is an element item with the [local name] "value". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. An element item with the same [local name] (i.e., "attribute", "element", "component", "group" or "member") as the translation of the NamedType corresponding to the identifier in the ChoiceValue SHALL be appended to the [children] of the element item. An attribute item with the [local name] "name" SHALL be added to the [attributes] of the , , , or element item. The [normalized value] of this attribute item is a qualified name for the expanded name of the NamedType. The translation of the Value in the ChoiceValue SHALL be added to the [children] or [attributes] of the , , , or element item. The translation of a SequenceValue or SetValue is an element item with the [local name] "value". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. If the SequenceValue or SetValue has a ComponentValueList, then the translation of each NamedValue nested in the ComponentValueList SHALL be appended to the [children] of the element item in the order in which their corresponding NamedType instances appear in the definition of the governing type. The translation of a SequenceOfValue or SetOfValue is an element item with the [local name] "value". An element item with the [local name] "annotation" MAY be added to the [children] of the element item. If the SequenceOfValue or SetOfValue has a NamedValueList, then the translation of each NamedValue nested in the NamedValueList SHALL be appended to the [children] of the element item. If the SequenceOfValue or SetOfValue has a ValueList, then an element item with the same [local name] (i.e., "element" or "component") as the element item in the [children] of the or element item in the translation of the governing type SHALL be Legg Expires 22 June 2007 [Page 56] INTERNET-DRAFT Abstract Syntax Notation X December 22, 2006 appended to the [children] of the element item for each Value nested in the ValueList. An attribute item with the [local name] "name" and [normalized value] "item" SHALL be added to the [attributes] of the or element item. The translation of the Value (from the ValueList) SHALL be added to the [children] or [attributes] of the or element item. The translation of a NamedValue is an element item with the same [local name] as the translation of the corresponding NamedType, i.e., "attribute", "element", "component", "group", "item" or "simpleContent". An attribute item with the [local name] "name" SHALL be