Assert that values fall within an interval — assert

Checks that every element of x lies within the interval [lower, upper]. Each end is independently inclusive (closed, the default) or exclusive (open) via lower_inclusive / upper_inclusive, so every interval shape is expressible: [a, b], ]a, b[, ]a, b], [a, b[. Pass NULL for a bound to leave that side unbounded (]-Inf, b], [a, Inf[). Comparisons use only < / >, so this works for any comparable type — numbers, integers, dates, date-times, even strings — and never coerces.

Usage

assert_between(
  x,
  lower = NULL,
  upper = NULL,
  lower_inclusive = TRUE,
  upper_inclusive = TRUE,
  na_ok = FALSE,
  null_ok = FALSE,
  arg = rlang::caller_arg(x),
  call = rlang::caller_env()
)

Arguments

x: Object to check.
lower: Lower bound, or NULL for unbounded below. Must be the same class as x (no coercion is performed); a mismatched class compares silently wrong.
upper: Upper bound, or NULL for unbounded above.
lower_inclusive: Single logical. If TRUE (default) the lower bound is inclusive (x >= lower); if FALSE it is exclusive (x > lower).
upper_inclusive: Single logical. If TRUE (default) the upper bound is inclusive (x <= upper); if FALSE it is exclusive (x < upper).
na_ok: Single logical. If FALSE (default) any NA in x fails the check; if TRUE, NA elements are ignored and only the non-missing values are range-checked. Either way x is returned unchanged (including any NA).
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_between(5, 0, 10) # [0, 10]
assert_between(0.5, 0, 1, lower_inclusive = FALSE) # ]0, 1]
assert_between(c(1, NA, 3), 0, 10, na_ok = TRUE)
assert_between(Sys.time(), lower = as.POSIXct("2000-01-01"))