Hi Robert, On 1 Apr., 10:25, Robert Bradshaw <rober...@math.washington.edu> wrote: > A conversion is like a cast, which tries to make the object if it > makes sense at all. This is useful, for example, during construction. > E.g. there's a conversion QQ -> ZZ, list -> QQ[x], or even str -> ZZ. > They are invoked with __call__. Coercions are the set of conversions > that happen automatically and implicitly, e.g. during arithmetic. We > don't want to support str + ZZ, and ZZ coerces to QQ but not the other > way around.
OK. So, say, the map from the base ring into a polynomial ring or matrix algebra or [etc pp] should be registered as a coercion, not as a conversion, right? If I am not mistaken, one can register a conversion even if a conversion has been registered before (in contrast to the attempt to register another coercion). Is that intended? > No, I don't think there's anything like that yet. OK, done. This will be on #9138. Cheers, Simon -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
