Joins need to check that y is a data.table

[hadley]

Moved from tidyverse/dplyr#1217, by @Helix123

library(dplyr)
library(dplyr)

dt <- data.table::data.table(x = 1:3, y = 3:1)
df <- data.frame(x = 3:1, z = 1:3)

anti_join(dt, df)
left_join(dt, df)

[krlmlr]

The error message is not nice, but the following works as expected:

anti_join(dt, df, copy = TRUE)
left_join(dt, df, copy = TRUE)

Low prio.

[hadley]

Probably need some special case like:

auto_copy_dt <- function(x, y) {
  if (is.data.frame(y)) {
    as.data.table(y)
  } else {
    dplyr::auto_copy(x, y, copy = copy)
  }
}

Latest reprex:

library(dtplyr)
library(dplyr, warn.conflicts = FALSE)

dt <- data.table::data.table(x = 1:3, y = 3:1)
df <- data.frame(x = 3:1, z = 1:3)

anti_join(dt, df)
#> Joining, by = "x"
#> Error in `[.data.frame`(y, , by$y, with = FALSE): unused argument (with = FALSE)
left_join(dt, df)
#> Joining, by = "x"
#> Source: local data table [3 x 3]
#> 
#> # A tibble: 3 x 3
#>       x     y     z
#>   <int> <int> <int>
#> 1     1     3     3
#> 2     2     2     2
#> 3     3     1     1

^{Created on 2019-06-13 by the reprex package (v0.2.1.9000)}

[hadley]

Resolved with lazy_dt methods:

library(dplyr, warn.conflicts = FALSE)
library(dtplyr)

dt <- lazy_dt(data.table::data.table(x = 1:3, y = 3:1))
df <- data.frame(x = 3:1, z = 1:3)

anti_join(dt, df)
#> Joining, by = "x"
#> Source: local data table [?? x 2]
#> Call:   `_DT1`[!`_DT2`, on = .(x)]
#> 
#> # … with 2 variables: x <int>, y <int>
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results
left_join(dt, df)
#> Joining, by = "x"
#> Source: local data table [?? x 2]
#> Call:   merge(`_DT1`, `_DT3`, all.x = TRUE, all.y = FALSE, by = "x")
#> 
#>       x     y     z
#>   <int> <int> <int>
#> 1     1     3     3
#> 2     2     2     2
#> 3     3     1     1
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results

^{Created on 2019-06-27 by the reprex package (v0.2.1.9000)}