step-call-pivot_longer.md
In dtplyr: Data Table Back-End for 'dplyr'

can pivot to multiple measure cols

Code
  show_query(step)
Output
  melt(DT, measure.vars = list(c("x1", "x2", "x3", "x4"), c("y1", 
  "y2", "y3", "y4")), variable.name = "set", value.name = c("x", 
  "y"), variable.factor = FALSE)[, `:=`(set = c("1", "1", "2", 
  "2", "3", "3", "4", "4"))]

errors on unbalanced datasets

Code
  pivot_longer(dt, everything(), names_to = c(".value", "id"), names_sep = "_")
Condition
  Error in `pivot_longer()`:
  ! `data.table::melt()` doesn't currently support melting of unbalanced datasets.

informative errors on unsupported features

Code
  dt %>% pivot_longer(names_ptypes = list())
Condition
  Error in `pivot_longer()`:
  ! `names_ptypes` is not supported by dtplyr
Code
  dt %>% pivot_longer(names_transform = list())
Condition
  Error in `pivot_longer()`:
  ! `names_transform` is not supported by dtplyr
Code
  dt %>% pivot_longer(values_ptypes = list())
Condition
  Error in `pivot_longer()`:
  ! `values_ptypes` is not supported by dtplyr
Code
  dt %>% pivot_longer(values_transform = list())
Condition
  Error in `pivot_longer()`:
  ! `values_transform` is not supported by dtplyr