Page created by Arjan Loeffen, last revision dd. 06/27/95 10:36:02

Statements on objects in SGML based document design

In the following overview I do not go into the object-oriented model on which the document design is based. The 'system' is assumed to be built out of objects only, following a SmallTalk or Actor approach. For instance, EXPRESSIONs and BLOCKs are objects themselves, and can be created and saved as any other object.

In the design I have avoided constructs that defy some essential object-oriented principles:

The objects described here model the following characteristics of the structural model of SGML, as extracted from the standard. The structural model can be said to adhere to the element structure information set (ESIS, WG8, N1035), as described in the SGML Handbook by C. Goldfarb (1988).


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The preceding image shows the type relations in the TBMS.

Nodes in a free tree

Units in document content

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The preceding image shows how units make up a document tree. Left the document, middle the units, right the associated text portions.

Special markers


SGML attributes

Content model

Character data