^<- ^{Charles F. Goldfarb} ^-> The HyTime Technical Corrigendum - Part I

(C)Copyright 1996 Charles F. Goldfarb. All rights reserved.

Primary Objectives

Correct several known minor problems
^{HyTime Architecture} Distinguish general rules for defining architectures from their use in defining HyTime architecture
Eliminate ambiguities in property sets, parsing context and their impact on location addressing
Correct flaw in sbento design

Additional Objectives

^<- ^DSSSL ^-> Alignment with DSSSL
- Query Language (HyQ -> SDQL)
- Expression language (HyOP + HyFunk -> DSSSL)
- ^<- ^Grove ^-> Model of parsed SGML (Groves)
Integrated 2nd edition
Test ISO/CS SGML publishing system

^<- ^{Extended Facilities} ^-> ^<- ^{SGML Extended Facilities} ^-> SGML Extended Facilities

General applicability to SGML
HyTime architecture is not required
Definition requirements for
^{General Facilities Architecture} General Facilities Architecture
Modular conformance : use any or all

^<- ^AFDR ^-> ^<- ^{Architectural Form Definition Requirements} ^-> Architectural Form Definition Requirements (AFDR)

^Architecture Define "enabling architectures" for SGML documents
^<- ^Element ^-> Element type, attribute and notation forms
Permits common processing tools across multiple document types
Documents are "derived" from architectures.
Multiple derivation levels and/or bases

^{Architectural Form} History of Architectural Forms

^Music 1984: SGML music standard proposed to ANSI
^<- ^{Steven R. Newcomb} ^-> ^<- ^SMDL ^-> 7/86: SMDL work begins (Goldfarb meets Newcomb)
^<- ^SMDL ^-> 6/89: HyTime split from SMDL
- ^<- ^DTD ^-> ^{Parameter Entity} Two DTDs connected by scores of parameter entities
6/90: Goldfarb proposes architectural forms
1990: HyTime becomes an architecture

^<- ^AFDR ^-> Key AFDR Concepts

^<- ^Meta-DTD ^-> Client document is "derived" from one or more "base" architectures (meta-DTDs)
Client identifies its base architectures via "architecture support declarations"
^{SGML Parser} ^<- ^Meta-DTD ^-> Any DTD can be a meta-DTD (even a derived DTD).
An SGML parser can recognize "architectural instances" (as well as normal document instance)

^<- ^Meta-DTD ^-> Meta-DTD Syntax

Conventional Comments
- Reftype
- Lextype
^<- ^Attribute ^-> ATTLIST Declaration Extensions
- Multiple ATTLIST declarations permitted for same element type
- Single ATTLIST declaration can apply to all element types
Planned for ISO 8879 revision

^<- ^AFDR ^-> Other AFDR Features

^<- ^Notation ^-> Notation Set Architecture
- Allow data attributes on start tags
- Notation text in content or attributes
Processing link architectures
- Association via link rules

^<- ^Architecture ^-> Architecture Status

Usable today for information modeling
- HyTime is an architecture
- Provides OOPS-like features for data
- Transparent to normal SGML parsing
^{SP Parser} Initial implementation in James Clark's SP
- Parses architectural instances
- Many markup minimization features
- ^<- ^DTD ^-> ^<- ^HTML ^-> Use with existing DTDs (e.g. HTML)

^<- ^Meta-DTD ^-> Famous AFDR Quotation

"I never meta-DTD I didn't like" -- Norm Scharpf, 11/20/96