Summary: CZ-0001 thru CZ-0012

[MURATA Makoto (FAMILY Given)]

Dear colleagues,

This mail is intended to provide a summary of the discussion 
about CZ-0001  thru CZ-0012 for the Part1 FPDAM1.

Czech is against the union of a SINGLE type.  An example in the 
strict version of dml-main.xsd  is:

  <xsd:simpleType name="ST_TextBulletSize">
    <xsd:union memberTypes="ST_TextBulletSizePercent"/>
  </xsd:simpleType>

Meanwhile, in the transitional version, this becomes the union 
of TWO types.

  <xsd:simpleType name="ST_TextBulletSize">
    <xsd:union memberTypes="ST_TextBulletSizePercent ST_TextBulletSizeDecimal"/>
  </xsd:simpleType>

Thus, the strict version requires the percent symbol, while the
transitional version allows integers without the percent symbol as well.

1) Keep the union (me)

The use of union minimizes the differences between transitional 
schemas and strict schemas.

Suppose that we decide to "merged" schemas by merging S and T 
and automatically generate S and T from such merged schemas.  Then, 
the use of union simplifies the merged schemas and the program for 
such automatic generation.

FYI: Prototypical "merged" schemas are already available. See
http://mailman.vse.cz/pipermail/sc34wg4/2010-January/001062.html

2) Drop the union (Jirka)

Using union of single type adds excessive complexity to the schema, 
and makes OOXML object model more complex in databinding tools.

Dropping union from strict schemas does not block "merged" schemas or 
automatic generation of strict schemas and transitional ones.  
We only have to add one simple additional step to turn singleton unions
into xs:restriction.


Cheers,
Makoto