Hi,
On 03/22/2013 01:31 AM, peter dalgaard wrote:
On Mar 22, 2013, at 05:57 , Hervé Pagès wrote:
Hi,
Maybe a compromise would be to just issue a warning without
deprecating? That way people who want to do anova(fit1)$P can
still do it. When working interactively, it's certainly convenient
(serious code however should probably stay away from partial matching).
That's what it does. Issuing a warning when users do X is pretty much
equivalent to deprecating X.
For now yes. But you won't keep it deprecated forever right?
And so you keep the semantic consistent with lists because yes,
consistency is important. data.frame inherits from list so any
operation that works on a list is expected to work on a data.frame,
preferably the same way (otherwise it will always be a BIG surprise
to the user/programmer). For example if I have to maintain someone
else code and see something like:
bar <- x$bar
and I know that 'x' is a list that contains atomic vectors of the
same length, I could have some good reasons to want to use a
data.frame instead of a list. And I would assume it's safe to
modify the code by adding the following line earlier in it:
x <- as.data.frame(x)
But with the proposed change to $.data.frame, I cannot make this
kind of assumption anymore...
No, but it's only a real problem if the component is not actually called "bar".
You could make the same point for environments, but they never allowed partial matching:
A data.fame is a list, not an environment. It would be silly for
me as a programmer to assume that replacing environment 'x' by
data.frame 'x' won't break the code.
H.
e <- as.environment(list(barbaric=666))
e$bar
NULL
e$barbaric
[1] 666
--
Hervé Pagès
Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M1-B514
P.O. Box 19024
Seattle, WA 98109-1024
E-mail: hpa...@fhcrc.org
Phone: (206) 667-5791
Fax: (206) 667-1319
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
