The Semantic Analyzer.
Abstract
Once a document is marked up using an SGML-defined markup language, an SGML parser can validate the document against a specified Document Type Definition (DTD). This process ensures that the document's tags conform to the structure imposed by the DTD. An SGML parser is a powerful tool for one class of markup problems, namely SGML syntactical errors. However, in the markup of CALS documents, many errors are still made, and go unchallenged, for lack of a similar tool for detecting them. Within the confines of its structural check, an SGML parser is powerless to examine the semantics of a document -- in other words, the parser cannot assess the relevance of a given piece of text inside a particular element. Besides SGML-related markup rules, each DTD entails certain application-specific syntactic requirements -- in the case of CALS, requirements that go beyond those specified in the MIL-M-28001 DTD. For instance, no SGML requirements are violated when a CALS paragraph is left empty, but this condition is still syntactically wrong for a CALS application. This syntactic problem is a symptom of an underlying semantic problem -- an empty paragraph is meaningless. The Semantic Analyzer enables more powerful document analysis, combining the power of an SGML parser with the comprehensive pattern-matching capabilities of Exoterica's XGML Translator. A specification language is provided for the Semantic Analyzer, in order to allow development of customized analysis programs for specialized SGML applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1991
- Accession Number
- ADA312762