SAG-DM-02 Type hierarchies

The correct place for a diagrammatic representation of the type hierarchy
used in the data model would appear to be in the data model book; other
specifications such as F&O should refer to it rather than repeating it.

There is no good overview of the type hierarchy anywhere, the information is
completely scattered. In particular, there is no explanation of the fact
that there are actually two independent but related type hierarchies, one
for "values" (of expressions) and one for "content" (of nodes). The fact
that we refer to both these overlapping spaces as having types means we need
to make it much clearer that there are two different spaces, and to show how
they are related to each other.

Michael Kay
Software AG

Received on Tuesday, 10 June 2003 11:49:46 UTC