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4.2.14 COMMENT Objects

The COMMENT object is a mechanism for encoding arbitrary data within an OOGL object. It can be used to keep track of data or pass data back and forth between external modules.


     COMMENT                 # key word
     name type   # individual name and type specifier
     { ... }             # arbitrary data

The data, which must be enclosed by curly braces, can include anything except unbalanced curly braces. The type field can be used to identify data of interest to a particular program through naming conventions.

COMMENT objects are intended to be associated with other objects through inclusion in a LIST object. (See LIST.) The "#" OOGL comment syntax does not suffice for data exchange since these comments are stripped when an OOGL object is read in to Geomview. The COMMENT object is preserved when loaded into Geomview and is written out intact.

Here is an example associating a WorldWide Web URL with a piece of geometry:

     { LIST
      { < Tetrahedron}
      {COMMENT GCHomepage HREF { }}

A binary COMMENT format is accepted. Its format is not consistent with the other OOGL binary formats. See Binary format. The name and type are followed by

     N Byte1 Byte2 ... ByteN

instead of data enclosed in curly braces.