s3-data.table.md
In constructive: Display Idiomatic Code to Construct Most R Objects

data.table

Code
  dt1 <- data.table::data.table(head(cars, 2))
  construct(dt1)
Output
  data.table::data.table(speed = 4, dist = c(2, 10))
Code
  construct(dt1, opts_data.table(selfref = TRUE))
Output
  data.table::data.table(speed = 4, dist = c(2, 10)) |>
    structure(.internal.selfref = constructive::.xptr("0x123456789"))
Code
  construct(dt1, opts_data.table("next"))
Output
  data.frame(speed = 4, dist = c(2, 10)) |>
    structure(
      class = c("data.table", "data.frame"),
      .internal.selfref = constructive::.xptr("0x123456789")
    )
Code
  construct(dt1, opts_data.table("list"))
Output
  list(speed = c(4, 4), dist = c(2, 10)) |>
    structure(
      row.names = c(NA, -2L),
      class = c("data.table", "data.frame"),
      .internal.selfref = constructive::.xptr("0x123456789")
    )
Code
  dt2 <- data.table::data.table(dt1, key = "speed")
  construct(dt2)
Output
  data.table::data.table(speed = 4, dist = c(2, 10), key = "speed")

recycle in data tables

Code
  construct(data.table::data.table(a = 1:2, b = c(1, 1)))
Output
  data.table::data.table(a = 1:2, b = 1)
Code
  construct(data.table::data.table(a = c(1, 1), b = c(1, 1)))
Output
  data.table::data.table(a = c(1, 1), b = 1)
Code
  construct(data.table::data.table(a = 1:2, b = factor(c("a", "a"))))
Output
  data.table::data.table(a = 1:2, b = factor("a"))
Code
  construct(data.table::data.table(a = 1:2, b = as.Date(c("2000-01-01",
    "2000-01-01"))))
Output
  data.table::data.table(a = 1:2, b = as.Date("2000-01-01"))

duplicate names in data tables

Code
  construct(data.table::data.table(a = 1, a = 2))
Output
  data.table::data.table(a = 1, a = 2)

non standard names in data tables

Code
  construct(structure(data.table::data.table(1), names = NULL), check = FALSE)
Output
  list(1) |>
    structure(
      row.names = c(NA, -1L),
      class = c("data.table", "data.frame"),
      .internal.selfref = constructive::.xptr("0x123456789")
    )
Code
  construct(structure(data.table::data.table(1), names = ""))
Output
  data.table::data.table(1) |>
    structure(names = "")
Code
  construct(structure(data.table::data.table(1), names = NA))
Output
  data.table::data.table(1) |>
    structure(names = NA_character_)
Code
  construct(structure(data.table::data.table(1), names = "keep.rownames"))
Output
  data.table::data.table(1) |>
    structure(names = "keep.rownames")
Code
  construct(structure(data.table::data.table(1), names = "check.names"))
Output
  data.table::data.table(1) |>
    structure(names = "check.names")
Code
  construct(structure(data.table::data.table(1), names = "key"))
Output
  data.table::data.table(1) |>
    structure(names = "key")
Code
  construct(structure(data.table::data.table(1), names = "stringsAsFactors"))
Output
  data.table::data.table(1) |>
    structure(names = "stringsAsFactors")
Code
  construct(structure(data.table::data.table(1, 2), names = c("a", "")))
Output
  data.table::data.table(a = 1, 2) |>
    structure(names = c("a", ""))
Code
  construct(structure(data.table::data.table(1, 2), names = c("a", NA)))
Output
  data.table::data.table(a = 1, 2) |>
    structure(names = c("a", NA))
Code
  construct(structure(data.table::data.table(1, 2), names = c("a",
    "keep.rownames")))
Output
  data.table::data.table(a = 1, 2) |>
    structure(names = c("a", "keep.rownames"))
Code
  construct(structure(data.table::data.table(1, 2), names = c("a", "check.names")))
Output
  data.table::data.table(a = 1, 2) |>
    structure(names = c("a", "check.names"))
Code
  construct(structure(data.table::data.table(1, 2), names = c("a", "key")))
Output
  data.table::data.table(a = 1, 2) |>
    structure(names = c("a", "key"))
Code
  construct(structure(data.table::data.table(1, 2), names = c("a",
    "stringsAsFactors")))
Output
  data.table::data.table(a = 1, 2) |>
    structure(names = c("a", "stringsAsFactors"))