On Friday, February 5, 2016 at 12:46:54 PM UTC-8, Nathann Cohen wrote: > > > Well, the call syntax for polynomials and symbolic expressions really > > benefits from arbitrary keywords. > > Yeah, I guess there is nothing wrong with > "an_expression.subs(whatever=4)" returning nothing even though > 'whatever' is not a variable appearing in an_expression. >
It returning nothing would probably be quite bad, and I don't think that's what happens. Whether an error or just an_expression unchanged is more appropriate depends on the context. In any case, whether "whatever" is a valid keyword can only be decided at runtime, so you're stuck with "**kwargs". And indeed, in the symbolic ring it's problematic on whether an error should be raised. You do want f = x g = x^2 f(x=1)^2-g(x=1) to work, but you would probably expect that h = f^2-g h(x=1) to work too (and in the latter, no x occurs, of course). However, sage: f=QQ['x'].0 sage: f(y=0) x would probably be better off ending in an error. -- 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.
