[cellml-discussion] Include_in_CellML_1.2 requested: [TrackerItem153] Allow multiple connections between the same pair of components

[Jonathan Cooper]

* David Nickerson <david.nickerson at nus.edu.sg> [2007-08-29 04:21]:
> Andrew Miller wrote:
> >>>   * Implementation experience suggests that it is no harder to allow multiple
> >>> connections between the same pair of components when writing simulation
> >>> software, but the extra constraint imposes more work on developers when writing
> >>> tools which try to validate the model.
> >>>     
> >> This seems to be a good reason to keep the rule as it is. Given there is 
> >> already a sever lack of CellML validation tools it seems a bad idea to 
> >> be making it more difficult for people to write such tools.
> >>   
> > I don't follow. Removing the constraint should make life easier for 
> > validation tools - it is one less thing they have to check.
> 
> ok - guess I misinterpreted your comment. However, given the only tools 
> close to CellML validators currently available already implement this 
> check, it would appear that its not too much work to do so.

Indeed - it's a single assertion in Schematron, for instance, and I
wouldn't think it'd be much harder in any other framework.

Overall, I don't have a strong opinion either way on this issue.  Just
removing the assertion should allow my software to still work with the
change.  I do recall however that COR used to (and maybe still does)
restrict models to having only one group element for a given relationship
type, for ease of implementation.  So there could be concerns in some
quarters.

Jonathan.

-- 
Jonathan Cooper      MSN: msn at jonc.me.uk      www: jonc.me.uk/

Our library has so many books they had to put it in a multi-story building.