case, patterns

[Filip Konvička]

>> Well, F:V might match against any feature-value pair. 
> ... unless...
>> you impose the standard arity order there, but I cannot really see 
>> why you
>> would want that. 
> In fact, there is a difference between l(f:V) and l(F:v) in that there 
> is no requirement on the uniqueness of values in a record, and in this 
> sense the pattern l(F:v ...) would be nondeterministic, provided no 
> requirement on sorting the features.  But I don't see why the question 
> 'does it contain the feature f?' would have to be, in general, more 
> interesting than 'does it contain a feature with the value v?'
Features and values are not equal. Look at the RecordC constraints, and 
think of your proposals in terms of incremental record specification.

Cheers,
Filip