This data needs to be taken into account in the language description as appropriate.
In particular the area about extensible selects needs examination.
Also, the discussion about alt maps appears suspicious.
============
`1.1 Impact of extension of select data types
The capability to define extensible select data types was added in edition 2 of the EXPRESS language.
Extension of a select data type may add alternate types. These may lead to different mappings for the application object with the select data type attribute, for the assertions that refer to the select data type, or both. The extension of a select data type requires also that the mapping specifications of those application objects are reconsidered that are referred in any assertion that involves the extended select data type.
The mapping specification of an application object with an extensible select data type attribute shall, therefore, be introduced with the following words:
This section specifies the mapping of the entity onto the resource entity . Depending on the extensions of the Select type <name(s) of the one or several select data type(s) of attributes of the current entity>, this mapping may be superseded in the application modules that define these extensions.
If, for an application element, the extension has no impact and if a general mapping and reference path has been defined (see 9.4.2), there is no need to provide a mapping specification for the extended select type.
In other cases, a mapping specification shall be provided:
¾ for the application object with the select data type attribute;
¾ for the assertions that refer to the extensible select data type, for all the data types added in the extension (that is, after the keyword WITH).
If the source object of an assertion whose target is a member of the select data type extension is not defined in the same schema, the following text shall introduce the mapping specification:
The application object and its mapping are defined in ISO 10303-. This mapping subclause extends the mapping of to include assertions defined in this part of ISO 10303.
NOTE 2 Documentation of the reference path of an attribute that refers to an extensible select type is specified in 9.4.2 .`
SELECT Extension Chain Semantics (moved from #7)
The *> and <* operators are defined but:
- Behavior with multi-level BASED_ON chains not specified
- Transitivity rules not specified
- Interaction between ARM and MIM extension hierarchies not specified
This data needs to be taken into account in the language description as appropriate.
In particular the area about extensible selects needs examination.
Also, the discussion about alt maps appears suspicious.
============
`1.1 Impact of extension of select data types
The capability to define extensible select data types was added in edition 2 of the EXPRESS language.
Extension of a select data type may add alternate types. These may lead to different mappings for the application object with the select data type attribute, for the assertions that refer to the select data type, or both. The extension of a select data type requires also that the mapping specifications of those application objects are reconsidered that are referred in any assertion that involves the extended select data type.
The mapping specification of an application object with an extensible select data type attribute shall, therefore, be introduced with the following words:
This section specifies the mapping of the entity onto the resource entity . Depending on the extensions of the Select type <name(s) of the one or several select data type(s) of attributes of the current entity>, this mapping may be superseded in the application modules that define these extensions.
If, for an application element, the extension has no impact and if a general mapping and reference path has been defined (see 9.4.2), there is no need to provide a mapping specification for the extended select type.
In other cases, a mapping specification shall be provided:
¾ for the application object with the select data type attribute;
¾ for the assertions that refer to the extensible select data type, for all the data types added in the extension (that is, after the keyword WITH).
If the source object of an assertion whose target is a member of the select data type extension is not defined in the same schema, the following text shall introduce the mapping specification:
The application object and its mapping are defined in ISO 10303-. This mapping subclause extends the mapping of to include assertions defined in this part of ISO 10303.
NOTE 2 Documentation of the reference path of an attribute that refers to an extensible select type is specified in 9.4.2 .`
SELECT Extension Chain Semantics (moved from #7)
The
*>and<*operators are defined but: