On 30/06/2015 1:57 PM, Hadley Wickham wrote:
> A slightly simpler formulation of the problem is:
>
> show <- function(...) stop("My show!")
> methods::setClass("Person", slots = list(name = "character"))
> methods::new("Person", name = "Tom")
> #> Error in (function (...) : My show!
Just to be clear: the complaint is that the auto-called show() is not
methods::show? I.e. after
x <- methods::new("Person", name = "Tom")
you would expect
show(x)
to give the error, but not
x
??
Duncan Murdoch
>
> Hadley
>
> On Tue, Jun 30, 2015 at 9:02 AM, Dean Attali <[email protected]> wrote:
>> Hi r-devel
>>
>> If you define a function named `show` or attach a package with an exported
>> `show` function, then printing/vieweing S4 objects breaks. This is probably
>> because the `print` function calls `show`, which is now masked.
>>
>> Example:
>>
>> show <- function() {}
>>> setClass("Person", slots = list(name = "character"))
>>> tom <- new("Person", name = "Tom")
>>> tom # error
>>> methods::show(tom) # works
>>
>>
>> The error was a surprise to me because I was under the assumption that
>> `show` would be namespaced and therefore should not break.
>> I'm wondering if this is intended behaviour, or if this is a problem. My
>> intuition, and Hadley agreed on Twitter, is that defining a `show` method
>> should not have such a grave effect on printing S4 objects.
>>
>> Thanks
>>
>> ---
>> http://deanattali.com
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> [email protected] mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>
>
>
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
