BULK Simple XML namespace
draft-thierry-bulk-xml-00

Abstract

This specification describes a BULK serialization of XML data.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on February 07, 2014.

Copyright Notice

Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 1.1. Conventions and Terminology
• 2. BULK XML namespace
• 2.1. XML 1.0 entity
• 2.2. XML 1.1 entity
• 2.3. Processing instruction
• 2.4. Comment
• 2.5. Element
• 2.6. Attribute
• 2.7. xml: namespace
• 2.8. xmlns: namespace
• 2.9. space preservation
• 3. References
• 3.1. Normative References
• 3.2. Informative references
• Appendix A. Shorthand examples
• Author's Address

1. Introduction

1.1. Conventions and Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

Literal numerical values are provided in decimal or hexadecimal as appropriate. Hexadecimal literals are prefixed with 0x to distinguish them from decimal literals.

BULK bytes sequences and expressions are described with the same conventions than used in the BULK 1.0 specification [BULK1]

2. BULK XML namespace

The Simple XML namespace is an official namespace identified by the UUID urn:uuid:8e9fbe9c-2b0c-5307-bb81-edb1a7727563 (BULK, http://www.w3.org/XML/Core/).

It is a simplistic notation for the XML data available after parsing an XML document is complete. As such, it doesn't provide a way to serialize some components of an XML document, such as the contents of the DTD or unparsed entities. In particular, the encoding declaration of the XML prolog is not serialized, as BULK sreams already carry encoding information. As for any other BULK data, everywhere within an Simple XML form, a stringenc form can appear.

An application writing Simple XML data SHOULD use rdf:prefix to denote element and attribute prefixed names and arrays for unprefixed names. The semantics of the rdf:prefix form are application-dependent; an application could choose to evaluate it without changing its value beforehand, thus using expanded names (cf. [XML-NAMES10] and [XML-NAMES11]), or follow the XML Infoset [XML-INFOSET] principle of keeping the namespace and local part of the name separate.

Note that Simple XML cannot store the original prefix associated with a namespace. The goal is to be able to serialize just enough data from a parsed XML document that an equivalent XML document can be unserialized. By equivalent, we mean that it would have the same semantics as the original XML document for applications using this XML format (but defining this latter equivalence in a remotely decent way is outside the scope of this specification).

Character data (corresponding to CDATA sections and #PCDATA in XML) SHOULD be serialized as arrays.

Note: authors of BULK XML namespaces are encouraged to define names in such a way that frequently-used expressions can be serialized as compactly as possible, using rdf:prefix, define, subst or any similar constructs. This is particularly straightforward and useful for enumerated attributes (but could be used for more complex structures).

2.1. XML 1.0 entity

name

0x1 (mnemonic: xml1.0 )

shape

( xml1.0 {content} )

This form denotes an entity (document entity or external entity) whose XML version is 1.0.

Type: Entity

2.2. XML 1.1 entity

name

0x2 (mnemonic: xml1.1 )

shape

( xml1.1 {content} )

This form denotes an entity (document entity or external entity) whose XML version is 1.1.

Type: Entity

2.3. Processing instruction

name

0x3 (mnemonic: pi )

shape

( pi {target} {content} )

Type: PI

2.4. Comment

name

0x4 (mnemonic: comment )

shape

( comment {content} )

Type: Comment

2.5. Element

name

0x5 (mnemonic: element )

shape

( element {name} {content} )

Type: Element

2.6. Attribute

name

0x6 (mnemonic: attribute )

shape

( attribute {name} {value} )

Type: Attribute

2.7. xml: namespace

name

0x7 (mnemonic: xml: )

value

( prefix "http://www.w3.org/XML/1998/namespace" )

2.8. xmlns: namespace

name

0x8 (mnemonic: xmlns: )

value

( prefix "http://www.w3.org/2000/xmlns/" )

2.9. space preservation

name

0x9 (mnemonic: preserve )

value

( attribute ( xml: "space" ) "preserve" )

3. References

3.1. Normative References

3.2. Informative references

Appendix A. Shorthand examples

Here are a couple of examples of the kind of definitions that can be used to increase compactness in an XML serialization.

First, this specification defines general forms for XML data. But namespaces can be dedicated to XML formats, with names for each element, attribute or PI:

• ( define ?rfc ( subst ( pi "rfc" ( rest 0 ) ) ) )
• ( define t ( subst ( element "t" ( rest 0 ) ) ) )

Secondly, recurring patterns can be abbreviated:

• ( define thang ( subst ( t ( attribute "hangText" ( arg 0 ) ) ( rest 1 )
• ( define verb ( subst ( spanx ( attribute "verb" ) ( rest 0 ) ) ) )

Author's Address