This is equivalent to base::typeof()
with a few differences that
make dispatching easier:
The type of one-sided formulas is "quote".
The type of character vectors of length 1 is "string".
The type of special and builtin functions is "primitive".
type_of(x)
x | An R object. |
---|
type_of()
is an experimental function. Expect API changes.
type_of(10L) #> Warning: `type_of()` is deprecated as of rlang 0.4.0. #> Please use `typeof()` or your own version instead. #> This warning is displayed once per session. #> [1] "integer" # Quosures are treated as a new base type but not formulas: type_of(quo(10L)) #> [1] "formula" type_of(~10L) #> [1] "formula" # Compare to base::typeof(): typeof(quo(10L)) #> [1] "language" # Strings are treated as a new base type: type_of(letters) #> [1] "character" type_of(letters[[1]]) #> [1] "string" # This is a bit inconsistent with the core language tenet that data # types are vectors. However, treating strings as a different # scalar type is quite helpful for switching on function inputs # since so many arguments expect strings: switch_type("foo", character = abort("vector!"), string = "result") #> [1] "result" # Special and builtin primitives are both treated as primitives. # That's because it is often irrelevant which type of primitive an # input is: typeof(list) #> [1] "builtin" typeof(`$`) #> [1] "special" type_of(list) #> [1] "primitive" type_of(`$`) #> [1] "primitive"