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Interdoc MeetingJanuary 21, 1982

Interdoc Concepts and Principles

Jim Mitchell:

The interchange format as a language

Transcription and rendition

Layers of the standard

Content, form, value, and structure

Jim Horning:

Features of the base language

Jim Mitchell:

Transcription and rendition fidelity

The interchange format as a language

An Interdoc script is a program in the Interdoc language

Transcription:
editor representation —> interchange
(document —> script)

Every script is transcribed before being editable

Rendition:
interchange —> editor representation
(script —> document)

Layers of the standard

Layer 0: The syntax of scripts

Layer 1: The semantics of the base language

Layer 2: The semantics of generally shared properties and attributes

Layer 3: The semantics of properties and attributes to be shared by groups of communicating editors

Content, form, value, and structure

Content: "What" is in the document

Form: "How" it is to be viewed

Structure: Intended relations among values

Issues in Transcription

Fidelity: R(T(document)) = document

Process in left-to-right, depth-first order—to transmit without first storing

Standard external environment: units, definitions, abbreviations, . . .

T(R(T(document))) need not necessarily be the same as T(document) — extra hints are okay

Standard versus editor-specific transcription

Issues in Regeneration

S1 ← T1( D1) D2 ← R2(S1) S2 ← T2(D2)
S1 = S2?D1 = R1(S2)?

S1 ← T1( D1) D’2 ← Edit(R2(S1)) S’2 ← T2(D’2)
What relation is there between S1 and S’2?

Determining which nodes have been altered directly or indirectly

Regenerating structure when relevant parts of the environment and contents have not changed since rendering

Can it be done as simply as normal transcription?

Requirements and Exclusions

An interchange standard must:

Use a universal character set
(graphic subset of ISO 646/ASCII)

Provide an acceptably efficient encoding

Be open-ended

Preserve document structure

Preserve document form

Provide faithful transcriptions

Simplify limited-fidelity rendition

Enable regeneration of scripts after editing with unaffected portions faithfully transcribed

Interdoc is not:

A file format

A standard for editing

A mechanism for combining documents

A substitute for other corporate standards

STANDARD DISCLAIMERS

1.WE ARE DESIGNING A STANDARD FOR INTERCHANGE, NOT EDITING.

2.EVERY SCRIPT IS RENDERED (parsed) BEFORE BEING EDITABLE.

3.STANDARDIZE CONCEPTS, NOT NAMES

4.COMBINING DOCUMENTS IS AN EDITOR, NOT AN INTERCHANGE TASK (corollary of 1).

5.GENSYM IS AN EDITOR FUNCTION (corollary of 1).

6.CHARACTER-SET AND LEXICAL ISSUES CAN BE RESOLVED AT THE END.

7.GET THE TECHNICAL BASIS RIGHT BEFORE WORRYING ABOUT THE POLITICAL ISSUES.