map_dtc renames col names

[mlr-org]

map_dtc renames col names

[mllg]

I think that this should throw an error. The elements to bind should be vectors, not data.tables.

[mllg]

OTOH, purrr allows this.

I see no obvious or easy solution for this. Sometimes you want the "inner" names, sometimes the "outer" names.

Unnaming xs would break this:

xs = list(a = 1, b = 2)
d = map_dtc(xs, identity)

[berndbischl]

OTOH, purrr allows this.

i find it pretty handy when f return datatables. and if purrr allows it, we should stay consistent.

Unnaming xs would break this:

xs = list(a = 1, b = 2)
d = map_dtc(xs, identity)

oops, totally correct. i guess we should only unname in case of datatables?
i think you are alreay committing this?

[berndbischl]

you solved it in this commit 3 days ago.
i added a further test to make sure

[berndbischl]

actually you didnt, an my test does test my issue.
if the list is named, we still have the same problem

[berndbischl]

i want this solved, I will now at least compare what purrr does

[berndbischl]

purrr works, as I want it
in both cases here, colnames "a" and "b" are created

library(purrr)

x1 = list(data.table(a = 1), data.table(b = 2))
x2 = list(foo = data.table(a = 1), bar = data.table(b = 2))

d1 = purrr::map_dfc(x1, identity)
print(d1)
d2 = purrr::map_dfc(x2, identity)
print(d1)

[berndbischl]

fixed NOW and added a test
I had to add a mini.map, in map_dtc, that slows the call down A BIT
but at least it works now

[mllg]

I did not fix because I was unsure about what behavior is wanted. Apparently we now just discard the "outer" names. I don't find it very intuitiv, but can live with it.

I've fixed your commit so that everything with a dimension works (i.e., data.frames and matrices).

[berndbischl]

I did not fix because I was unsure about what behavior is wanted. Apparently we now just discard the "outer" names. I don't find it very intuitiv,

well in the OP I suggested exactly that. you never said you want something else
(you said you wanted it to work with vectors, i then immediately agreed)

also: we are now 100% in alignment with purrr.
(that I posted today)
i thought we wanted exactly that?