R devel - Nov 2019 - Inappropriate class(o)[!inherits(o,"AsIs")] in get_all_vars

SVN?revision?77401?changes
????????x[isM]?<-?lapply(x[isM],?function(o)?`class<-`(o,?class(o)[class(o)?!=?"AsIs"]))
to
????????x[isM]?<-?lapply(x[isM],?function(o)?`class<-`(o,?class(o)[!inherits(o,"AsIs")]))
in?function?'get_all_vars'?in?src/library/stats/R/models.R?in?R?devel.

The?change?is?inappropriate.

class(o)[class(o)?!=?"AsIs"]?removes?"AsIs"?from?class(o),?giving?class(o)?without?"AsIs".

On?the?other?hand,?inherits(o,"AsIs")?is?just?a?single?logical?value.?If?"AsIs"?is?in
class(o),?inherits(o,"AsIs")?is?TRUE. In that
case,?by?recycling?of?logical?index,?class(o)[!inherits(o,"AsIs")]?removes?all?elements?of?class(o),?giving?character(0).

>>>>> suharto anggono--- via R-devel 
>>>>>     on Sun, 17 Nov 2019 10:34:31 +0000 writes:
    > SVN revision 77401 changes
    >         x[isM] <- lapply(x[isM], function(o) `class<-`(o,
class(o)[class(o) != "AsIs"]))
    > to
    >         x[isM] <- lapply(x[isM], function(o) `class<-`(o,
class(o)[!inherits(o,"AsIs")]))
    > in function 'get_all_vars' in src/library/stats/R/models.R in R
devel.

    > The change is inappropriate.

    > class(o)[class(o) != "AsIs"] removes "AsIs" from
class(o), giving class(o) without "AsIs".

    > On the other hand, inherits(o,"AsIs") is just a single
logical value. If "AsIs" is in class(o), inherits(o,"AsIs")
is TRUE. In that case, by recycling of logical index,
class(o)[!inherits(o,"AsIs")] removes all elements of class(o), giving
character(0).

Thank you, Suharto !

You are obviously right,  and I'm a bit embarrassed by my
overzealousness to follow my own recommendations in the  R Blog

  http://bit.ly/R_blog_class_think_2x

{*wrongly*: The recommendation was to "think again" ...}

It's a "shame" that the wrong code did not trigger any checks,
so if anybody has time... I'd be grateful for such a regression
check.

Martin

>>>>> Martin Maechler 
>>>>>     on Mon, 18 Nov 2019 12:15:38 +0100 writes:
>>>>> suharto anggono--- via R-devel 
>>>>>     on Sun, 17 Nov 2019 10:34:31 +0000 writes:
    >> SVN revision 77401 changes
    >> x[isM] <- lapply(x[isM], function(o) `class<-`(o,
class(o)[class(o) != "AsIs"]))
    >> to
    >> x[isM] <- lapply(x[isM], function(o) `class<-`(o,
class(o)[!inherits(o,"AsIs")]))
    >> in function 'get_all_vars' in src/library/stats/R/models.R
in R devel.

    >> The change is inappropriate.

    >> class(o)[class(o) != "AsIs"] removes "AsIs"
from class(o), giving class(o) without "AsIs".

    >> On the other hand, inherits(o,"AsIs") is just a single
logical value. If "AsIs" is in class(o), inherits(o,"AsIs")
is TRUE. In that case, by recycling of logical index,
class(o)[!inherits(o,"AsIs")] removes all elements of class(o), giving
character(0).

    > Thank you, Suharto !

    > You are obviously right,  and I'm a bit embarrassed by my
    > overzealousness to follow my own recommendations in the  R Blog

    > http://bit.ly/R_blog_class_think_2x

    > {*wrongly*: The recommendation was to "think again" ...}

    > It's a "shame" that the wrong code did not trigger any
checks,
    > so if anybody has time... I'd be grateful for such a regression
    > check.

Once I started thinking, it was easy to modify the previous
reg.check  to trigger in the case of the erronous r77401.

Fixed now in 77435.
Martin