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

formula

Code
  fml1 <- formula(lhs ~ rhs, .GlobalEnv)
  construct(fml1)
Output
  lhs ~ rhs
Code
  construct(fml1, opts_formula(constructor = "formula"))
Output
  formula(lhs ~ rhs)
Code
  construct(fml1, opts_formula(constructor = "new_formula"))
Output
  rlang::new_formula(quote(lhs), quote(rhs))
Code
  construct(fml1, opts_formula(environment = TRUE))
Output
  lhs ~ rhs
Code
  construct(fml1, opts_formula(constructor = "formula", environment = FALSE))
Output
  formula(lhs ~ rhs)
Code
  construct(fml1, opts_formula(constructor = "new_formula", environment = FALSE))
Output
  rlang::new_formula(quote(lhs), quote(rhs))
Code
  fml2 <- formula(~rhs, .GlobalEnv)
  construct(fml2)
Output
  ~rhs
Code
  construct(fml2, opts_formula(constructor = "formula"))
Output
  formula(~rhs)
Code
  construct(fml2, opts_formula(constructor = "new_formula"))
Output
  rlang::new_formula(NULL, quote(rhs))
Code
  construct(fml2, opts_formula(environment = TRUE))
Output
  ~rhs
Code
  construct(fml2, opts_formula(constructor = "formula", environment = FALSE))
Output
  formula(~rhs)
Code
  construct(fml2, opts_formula(constructor = "new_formula", environment = FALSE))
Output
  rlang::new_formula(NULL, quote(rhs))
Code
  fml3 <- fml1
  attr(fml3, "foo") <- "bar"
  construct(fml3)
Output
  (lhs ~ rhs) |>
    structure(foo = "bar")
Code
  construct(fml3, opts_formula(environment = TRUE))
Output
  (lhs ~ rhs) |>
    structure(foo = "bar")
Code
  fml4 <- fml1
  class(fml4) <- "foo"
  construct(fml4)
Output
  quote(lhs ~ rhs) |>
    structure(class = "foo", .Environment = .GlobalEnv)
Code
  fml5 <- fml1
  class(fml5) <- NULL
  construct(fml4)
Output
  quote(lhs ~ rhs) |>
    structure(class = "foo", .Environment = .GlobalEnv)
Code
  fml6 <- quote(lhs ~ rhs)
  construct(quote(lhs ~ rhs))
Output
  quote(lhs ~ rhs)
Code
  construct(fml1, opts_formula("next"))
Output
  quote(lhs ~ rhs) |>
    structure(class = "formula", .Environment = .GlobalEnv)