On Sunday, July 14, 2013 4:49:36 AM UTC-4, vdelecroix wrote: > As Volker Braun mentioned, the main problem is that it is possible to > write p(i) in Sage! I suggest that we remove the __call__ attribute of > permutations (it does not exists in GAP but I do not know for other > softwares). If we consider permutations as a function on a finite set, then > it should definitely be a left action (this is because of Python). One > caveheat of this removal is that we may want to access to p as a list and > for list we have the notation l[i] which is as bad as a left action. > Perhaps we should also remove the __getitem__ attribute.
But the call syntax is just very handy. How about we show a warning the first time the call syntax is used with a right-action-permutation but not with the yet-to-be-written left-action-permutation. Proper right actions could be implemented in a multiplicative notation via __rmul__. The warning could be avoided with a special right_action() method or with an optional keyword argument p(i, right=True). -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
