Abs,
Inline.
On Thu, Mar 28, 2019 at 8:10 PM Abs Spurdle wrote:
> I know I said that I had no further comments on object oriented semantics.
> However, I found a contradiction in the R documentation.
>
>
> Gabriel Becker wrote:
> > So, there are implicit classes, but *only when the data object
I know I said that I had no further comments on object oriented semantics.
However, I found a contradiction in the R documentation.
Gabriel Becker wrote:
> So, there are implicit classes, but *only when the data object is NOT an
"R object"
In the R Language Definition:
> The R specific function
On Wed, Mar 27, 2019 at 6:27 PM Abs Spurdle wrote:
>
> > the prison made by ancient design choices
>
> That prison of ancient design choices isn't so bad.
>
> I have no further comments on object oriented semantics.
> However, I'm planning to follow the following design pattern.
>
> If I set the c
> Abs Spurdle
> on Thu, 28 Mar 2019 12:26:36 +1300 writes:
>> the prison made by ancient design choices
> That prison of ancient design choices isn't so bad.
> I have no further comments on object oriented semantics.
> However, I'm planning to follow the following des
> the prison made by ancient design choices
That prison of ancient design choices isn't so bad.
I have no further comments on object oriented semantics.
However, I'm planning to follow the following design pattern.
If I set the class of an object, I will append the new class to the
existing clas
I would recommend reading https://adv-r.hadley.nz/base-types.html and
https://adv-r.hadley.nz/s3.html. Understanding the distinction between
base types and S3 classes is very important to make this sort of
question precise, and in my experience, you'll find R easier to
understand if you carefully d
Abs et al,
Ok, so I have just gone and re-read the docs again. My language was a more
absolute than it should have been; *however*, I was still correct for the
cases under discussion.
>From ?UseMethod (emphasis mine)
An R object is a data object which has a ‘class’ attribute (and
this can
> you had seemed to be presenting it as something new in 3.5.3. I would be
surprised if the behavior doesn't go all the way back to whenever
head.function was added.
My bad.
I'm just surprised I've never noticed these problems before.
> S3 classes have no formal definitions at all
> I'm not sure
I think this goes back to SV4 (c. late 1990's). The is. functions
are much older (c. mid 1970's) , from before any class system was in S.
is() and inherits() were introduced with the S4 class system and were meant
to escape from the prison made by ancient design choices.
Bill Dunlap
TIBCO Softwa
Hi Abs,
Lets try to remain civil even when disagreeing about major design
philosophies, ok?
On Tue, Mar 26, 2019 at 2:08 PM Abs Spurdle wrote:
> If I can merge this thread with the one I started yesterday...
>
> > "If the object does not have a class attribute, it has an implicit
> class..."
>
If I can merge this thread with the one I started yesterday...
> "If the object does not have a class attribute, it has an implicit
class..."
> which I take to mean that if an object does have a class attribute it
does not also have an implicit class.
> I think this is reasonable behavior. Conside
Hello,
Here is another example.
df1 <- data.frame(a = 1:3, b = 4:6)
inherits(df1, "data.frame")
#[1] TRUE
class(df1)
#[1] "data.frame"
inherits(df1, "list")
#[1] FALSE
This is documented behavior, the help page ?inherits says
The function class prints the vector of names of classes an objec
In the case of inherits (at least) this seems intended.
The help page says:
"If the object does not have a class attribute, it has an implicit class..."
which I take to mean that if an object does have a class attribute it does not
also have an implicit class.
The behavior you noted below will
> I have noticed a discrepancy between is.list() and is(x, “list”)
There's a similar problem with inherits().
On R 3.5.3:
> f = function () 1
> class (f) = "f"
> is.function (f)
[1] TRUE
> inherits (f, "function")
[1] FALSE
I didn't check what happens with:
> class (f) = c ("f", "function")
H
Hi R-devel,
I have noticed a discrepancy between is.list() and is(x, “list”), which I
previously believed to be synonymous. On R version 3.5.2 (2018-12-20):
data(iris)
is.list(iris)# TRUE
is(iris, “list”) # FALSE
Is this discrepancy intentional?
Kind regards,
Shian Su
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