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Ensure the Truth of R Expressions in a Data Environment

Source: R/stopifnot.r
stopifnot.with.Rd

Wrapper around stopifnot2 that evaluates R expressions in an environment constructed from data.

Usage

stopifnot.with(data, ..., call. = TRUE)

Arguments

data

data to use for constructing an environment. This may be an environment, a list, a data.frame, or an integer as in sys.call.

...

any number of R expressions, which should each evaluate to (a logical vector of all) TRUE. If named, the names will be used in lieu of the default error message.

call.

call, logical, integer, or environment. logical, indicating if the calling call should become part of the error message with same semantics as stop. integer, specifying how many calls to go 'up' the call stack to extract a call for the error message. A value of 0 will give the call to stop2() itself, 1 will give the call of the caller, and so on. Numeric values are coerced to integer and absolute values are taken. Values outside either boundary of the call stack will be clamped to the nearest boundary. environment, which will be matched against the calling stack and the corresponding call will be shown.

Details

If any of the expressions are not all TRUE, stop is called, producing an error message indicating the first expression which was not (all) true. See stopifnot and stopifnot2 for full details.

Special care must be taken for handlers on the call stack, as they may affect the call displayed in the error or warning message. In such instances, passing an environment to call. may be helpful.

See also

stop2, warning2 and message2 for errors, warnings and messages with call information.

Examples

try(stopifnot.with(data.frame(x = 1, y = 2), x == y))
#> Error in eval(expr, envir) : 
#>   with data.frame(x = 1, y = 2) : x == y is not TRUE
try(stopifnot.with(list(x = 1, y = 2), all.equal(x, y)))
#> Error in eval(expr, envir) : 
#>   with list(x = 1, y = 2) : x and y are not equal:
#>   Mean relative difference: 1

f1 <- function(x, ..., call.) stopifnot.with(x, ..., call. = call.)
f2 <- function(x, ..., call.) f1(x, ..., call. = call.)
f <- function(x, ..., call.) f2(x, ..., call. = call.)

x <- list(a = 1, b = 2)
try(f(x, a == b, call. = FALSE))
#> Error : with x : a == b is not TRUE
try(f(x, a == b, call. = TRUE))
#> Error in f1(x, ..., call. = call.) : with x : a == b is not TRUE

try(f(x, a == 1, b < 1, call. = 0))
#> Error in stopifnot.with(x, ..., call. = call.) : 
#>   with x : b < 1 is not TRUE
try(f(x, b > 3, call. = 1))
#> Error in f1(x, ..., call. = call.) : with x : b > 3 is not TRUE
try(f(x, a != 1, call. = 2))
#> Error in f2(x, ..., call. = call.) : with x : a != 1 is not TRUE

f <- function(x, ...) {
  e <- environment()
  f1(x, ..., call. = e)
}

try(f(x, a == 1, b < 1))
#> Error in f(x, a == 1, b < 1) : with x : b < 1 is not TRUE