DEDSL PVL Implementation

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• DEDSL PVL Implementation
• - Major Changes -
• - Open Points -
• Corina Boer (Corina.Boer_at_cisi.cnes.fr)
• CS-SI

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DEDSL PVL Major Changes

• History
• At Vilspa in November 1999, the focus was on the
  Abstract Syntax document.
• Most of the comments came from John Garret and
  were taken into account after the meeting.
• During the telecons after Vilspa, the discussions
  led to a restructuring of the document and a set
  of open points.

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DEDSL PVL Major Changes

• Restructuring
• The ASN.1 specification has been suppressed.
• The presentation of the descriptors and
  attributes restated a lot of the DEDSL Abstract
  Syntax Recommendation.
• Therefore, a shorter presentation in tabular form
  has been agreed and is now in the document.
• The following point of view has been agreed
• The reader is familiar with the Abstract Syntax
  Recommendation and the PVL Recommendation.

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DEDSL PVL Major Changes

• A table has been added presenting the
  correspondence between the DEDSL Types and PVL
  Types.
• It has led to the use of the GROUP
  construction for an attribute defined as being a
  list or a choice with a variable number of
  elements due to their optional characteristic.
• The figures representing the different
  attributes for a dictionary or a data entity and
  the different descriptors for an attribute have
  been suppressed due to the increase of
  construction possibilities.

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DEDSL PVL Major Changes
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DEDSL PVL Major Changes

• The presentation of an elementary attribute has
  become more succinct.
• Example DICTIONARY_NAME
• DEFINITION Human readable name for the Data
  Entity Dictionary.
• PVL TYPE Unquoted String
• EXAMPLE VALUE DICTIONARY_NAME
  CDPP_Plasma_Dictionary
• The presentation of a composite attribute of type
  List or Choice has changed as previously
  mentioned.
• Example COMPONENT
• Its Abstract Syntax definition is Identifier(a
  .. b).

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DEDSL PVL Major Changes
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DEDSL PVL Major Changes
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DEDSL PVL Open Points

• A certain number of points are still open and
  are
• the presentation of a complete DEDSL dictionary
  as a set of higher-level blocks with selected
  names,
• the location of the USER_DEFINED_ATTRIBUTES
  block,
• the presentation of the different necessary
  examples,
• the contents of some examples,
• the explanations about the inheritance examples,
• the introduction lines for the different
  sections,
• and any other point raising up during the meeting
  ...