`semi_join` does not coerce `y` to `lazy_dt`

[dakvid]

Version 1.2.0 has some great new features, but has broken semi_join (or all my uses of it anyway 😀) as the second argument is no longer coerced from a data.table to a lazy_dt. The error message didn't make any sense until I came across #278 but that helped me deduce what was happening.

library(dplyr, warn.conflicts = FALSE)      # 1.0.7
library(data.table, warn.conflicts = FALSE) # 1.14.2
library(dtplyr, warn.conflicts = FALSE)     # 1.2.0

x <- data.table(a = 1:4, b = c(1:2, 1:2))
y <- data.table(b = 2L)

inner_join(x, y)
#> Joining, by = "b"
#> Source: local data table [2 x 2]
#> Call:   `_DT1`[`_DT2`, on = .(b), nomatch = NULL, allow.cartesian = TRUE]
#> 
#>       a     b
#>   <int> <int>
#> 1     2     2
#> 2     4     2
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results
full_join(x, y)
#> Joining, by = "b"
#> Source: local data table [4 x 2]
#> Call:   setcolorder(merge(`_DT3`, `_DT4`, all = TRUE, by.x = "b", by.y = "b", 
#>     allow.cartesian = TRUE), 2:1)
#> 
#>       a     b
#>   <int> <int>
#> 1     1     1
#> 2     3     1
#> 3     2     2
#> 4     4     2
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results
anti_join(x, y)
#> Joining, by = "b"
#> Source: local data table [2 x 2]
#> Call:   `_DT5`[!`_DT6`, on = .(b)]
#> 
#>       a     b
#>   <int> <int>
#> 1     1     1
#> 2     3     1
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results
semi_join(x, y)
#> Error in step_join(x, y, on = by, style = "semi"): is_step(y) is not TRUE
semi_join(x, y %>% lazy_dt())
#> Joining, by = "b"
#> Source: local data table [2 x 2]
#> Call:   `_DT8`[unique(`_DT8`[`_DT9`, which = TRUE, nomatch = NULL, on = .(b)])]
#> 
#>       a     b
#>   <int> <int>
#> 1     2     2
#> 2     4     2
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results

[dakvid]

Thank you! 🙏

[mgirlich]

You're welcome 😄