On Thursday, October 13, 2016 at 12:16:36 PM UTC-7, John Cremona wrote:
> Kwankyu's point is also a good one.  It really is not acceptable (from 
> a user's point of view) to ask if there any coercions, be told there 
> are none, and then be prevented from defining one! 

It's a necessity for sanity, though: These parents are global objects, so 
they should be immutable in their behaviour. Once it has been decided there 
is no coercion to some existing object, it cannot happen that later on, 
such a coercion is available. That's observably mutated behaviour. It can 
also cause inconsistencies in the coercion discovery: the fact that a 
coercion was NOT found can have forced the construction and caching of a 
coercion elsewhere. This could be inconsistent with later discoveries if 
there is now a coercion found.

You received this message because you are subscribed to the Google Groups 
"sage-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to sage-devel+unsubscr...@googlegroups.com.
To post to this group, send email to sage-devel@googlegroups.com.
Visit this group at https://groups.google.com/group/sage-devel.
For more options, visit https://groups.google.com/d/optout.

Reply via email to