mirai_map requires explicitly naming all columns?

[D3SL]

I've been trying to make more use of mirai_map() with dataframes but it seems like it requires explicitly naming every column in a dataframe. I may be failing to understand the documentation but it seems to me there's no real explanation of this behavior. How is mirai_map() intended to be used with dataframes? And is programmatic use without explicitly naming every column in the function possible?

For example the below throws an error about unused arguments for each column not passed to the anonymous function's arguments:

library(mirai)
daemons(6)
output<-mirai_map(
  mtcars,
  function(mpg,cyl){
    paste0(mpg,cyl)
  }
)
output[]
daemons(0)

$`Mazda RX4`
'miraiError' chr Error in (function (mpg, cyl) : unused arguments (disp = base::quote(160), hp = base::quote(110), drat = base::quote(3.9), wt = base::quote(2.62), qsec = base::quote(16.46), vs = base::quote(0), am = base::quote(1), gear = base::quote(4), carb = base::quote(4))
$`Mazda RX4 Wag`
'miraiError' chr Error in (function (mpg, cyl) : unused arguments (disp = base::quote(160), hp = base::quote(110), drat = base::quote(3.9), wt = base::quote(2.875), qsec = base::quote(17.02), vs = base::quote(0), am = base::quote(1), gear = base::quote(4), carb = base::quote(4))

Using ... avoids this, but causes other unintuitive behavior:

library(mirai)
daemons(6)
output<-mirai_map(
  mtcars,
  function(...){
    paste0(mpg,cyl)
  }
)
output[]
daemons(0)

$`Mazda RX4`
'miraiError' chr Error in (function (...) : object 'mpg' not found
$`Mazda RX4 Wag`
'miraiError' chr Error in (function (...) : object 'mpg' not found

I am not sure if this is the intended behavior, or I'm outside of the intended use case here.

[shikokuchuo]

I think you understand what multiple map does with a dataframe.

Your second example comes close, but you don't define mpg and cyl in your anonymous function so there's no way for paste0() to find those variables.

Below is the simplest solution:

library(mirai)
daemons(6)
mirai_map(
  mtcars,
  function(mpg, cyl, ...) {
    paste0(mpg, cyl)
  }
)[]
daemons(0)

If your function just takes ..., then you'd need to convert what's passed in by e.g. list(...) and going from there.

This is just how R behaves and isn't something introduced by mirai.