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Method for Implementing Bidirectional Datastream Transforms

IP.com Disclosure Number: IPCOM000100702D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 4 page(s) / 141K

Publishing Venue

IBM

Related People

Bolan, RJ: AUTHOR [+7]

Abstract

A method is described which relates to the field of text processing and, more specifically, datastream transforms. The method is used to bidirectionally transform documents at the revisable level without loss of information. The format of both the source and target datastreams is externally specified which allows complete customization of the conversion processes and selection at invocation time of a variety of conversion applications.

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This is the abbreviated version, containing approximately 48% of the total text.

Method for Implementing Bidirectional Datastream Transforms

       A method is described which relates to the field of text
processing and, more specifically, datastream transforms. The method
is used to bidirectionally transform documents at the revisable level
without loss of information.  The format of both the source and
target datastreams is externally specified which allows complete
customization of the conversion processes and selection at invocation
time of a variety of conversion applications.

      This method is used to implement a pair of programs which
convert from the layout-based RFTDCA (Revisable-Form-Text Document
Content Architecture) datastream to a tag-based GML (Generalized
Markup Language) datastream and vice versa.  A Parser program
converts RFTDCA documents to GML documents, while a Deparser program
converts GML or non-RFTDCA documents into RFTDCA documents.

      Fig. 1 is an example of a RFTDCA control converted to a GML
tag.  The elements of the GML tag are:
      PIP is the tagname of this GML tag.
      What follows are attributes of this GML tag:
           The first attribute has an attribute name of
           pagewid, with an attribute value of 12240.
           The last attribute has an attribute name of
           lastbtl, with an attribute value of 14400.
      The period ends the PIP tag.

      RFTDCA defines a comprehensive set of these controls, each
possessing a different format, or semantics, as defined by the
architecture.

      At the heart of the programs is the following method for
achieving bidirectional transforms with full customization
capabilities:
           A common Map File is used to specify both the format of
the input datastream (e.g., RFTDCA) and the format of the output
datastream (e.g., GML).  By parsing this Map File first, the task of
converting to either GML or RFTDCA becomes greatly simplified and
very efficient from a software development point of view.

      The map File "maps" RFTDCA controls to GML tags and vice versa.
 The Parser uses the map file to "map" an RFTDCA control to a GML tag
with attributes, as required.  The Deparser also uses the map file to
"map" a GML tag with attributes to an RFTDCA control.  Each such
mapping in the map file is called a map file entry .  It is also
the map file which directs the Parser and Deparser on how to
interpret or create the RFTDCA controls or GML tags.  Fig. 2 shows
the map file entry for the PIP control conversion example in Fig. 1.
      The entry for Fig. 2 is interpreted as follows:
           The first line indicates that the RFTDCA control
identified by the E50700 hexadecimal bytes, with minimum length 19
and maximum length 24, is to be converted to the "PIP" tag.
           Anything enclosed within "/*" and "*/" are comments, and
can be ignored.
           The second line indicates the nex...