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Assert that an object has an exact length

Source: R/length.R
assert_length.Rd

Assert that an object has an exact length

Usage

assert_length(
  x,
  expected_length,
  null_ok = FALSE,
  arg = rlang::caller_arg(x),
  call = rlang::caller_env()
)

Arguments

x

Object to check.

expected_length

Single non-negative whole number: the required length.

null_ok

Single logical. If TRUE, a NULL value passes the check without error. Use this for optional arguments that default to NULL. Defaults to FALSE, so NULL is rejected unless you opt in.

arg

Name used to refer to x in error messages. Defaults to the name of the expression passed as x.

call

Environment used as the error's call context. Defaults to the calling function, so errors point at the user's code.

Value

The input x, invisibly.

Examples

assert_length(1:3, 3)