The type of an R object

TYPEOF is a function-like macro that determines the type of an SEXPREC object.

Arguments

x	an SEXP pointer.

Value

A SEXPTYPE value.

Declaration

#define TYPEOF(x) ((x)->sxpinfo.type)

In Rinternals.h.

See also

typeof

Examples

# Determine R objects' SEXPTYPEs
sexptype <- inline::cfunction(c(x = "ANY"),
 ' SEXP type_value;
   type_value = PROTECT(Rf_ScalarInteger(TYPEOF(x)));
   UNPROTECT(1);
   return type_value;
 ' SEXP type_value;
   type_value = PROTECT(Rf_ScalarInteger(TYPEOF(x)));
   UNPROTECT(1);
   return type_value;
 ')

# NULL, returns 0
sexptype(NULL)
#> [1] 0
# an empty pairlist also returns 0
sexptype(pairlist())
#> [1] 0

# symbol, returns 1
sexptype(as.symbol('a'))
#> [1] 1

# dotted pair list, returns 2
sexptype(pairlist(a = 1))
#> [1] 2

# closure, returns 3
sexptype(function(x) {x + 1})
#> [1] 3

# environment, returns 4
sexptype(.GlobalEnv)
#> [1] 4

# promises, returns 5
# But how to get one?

# language (call and formulae), returns 6
sexptype(call("sin", pi))
#> [1] 6
sexptype(~ x + 2)
#> [1] 6

# special forms, returns 7
sexptype(.Internal)
#> [1] 7

# builtin non-special forms, returns 8
sexptype(.Primitive("sqrt"))
#> [1] 8

# "scalar" string type (internal only), would return 9
# No way of getting hold of one of this in R land

# logical vectors, returns 10
sexptype(TRUE)
#> [1] 10
sexptype(FALSE)
#> [1] 10
sexptype(NA)
#> [1] 10

# codes 12 and 13 are no longer in use
# used to be for factors and ordered factors in the 1990s

# integer vectors, returns 13
sexptype(1L)
#> [1] 13
sexptype(factor('as')) # still an integer vector
#> [1] 13

# real vectors, returns 14
sexptype(1)
#> [1] 14
sexptype(pi)
#> [1] 14
sexptype(double(1))
#> [1] 14
sexptype(numeric(1))
#> [1] 14

# complex vectors, returns 15
sexptype(1i)
#> [1] 15
sexptype(0i)
#> [1] 15
sexptype(0 + 1i)
#> [1] 15
sexptype(NA_complex_)
#> [1] 15

# string vectors , returns 16
sexptype("alice in wonderland")
#> [1] 16

# TODO: dot-dot-dot object, returns 17

# TODO: "any" args, returns 18

# generic vectors, i.e., lists, returns 19
sexptype(list())
#> [1] 19

# expression, returns 20
sexptype(expression(x + 2))
#> [1] 20

# TODO: byte code, returns 21

# TODO: external pointer, returns 22

# TODO: weak reference, returns 23

# raw bytes, returns 24
sexptype(raw(2))
#> [1] 24

# TODO: S4, non-vector, returns 25

# TODO: fresh node created in new page, returns 30

# TODO: node released by GC, returns 31

# TODO: Closure or Builtin or Special, returns 99