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Ensure the Truth of R Expressions with Call Information

Source: R/stopifnot.r
stopifnot2.Rd

Wrapper around stopifnot that leaves only the ... argument and adds a call. argument that shows a call in the error message that is derived from the call stack. warningifnot() implements the same functionality but produces a warning instead of an error.

Usage

stopifnot2(..., call. = TRUE)

warningifnot(..., warn.all = FALSE, call. = TRUE)

Arguments

...

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.

warn.all

logical, indicating if all failed expressions should produce warnings, or only the first failed expression. Default is FALSE, which means only the first failed expression will produce a warning.

Value

Called for side effects only.

Details

If any of the expressions are not all TRUE, stop or warning is called, producing an error/warning message indicating the first (or all, if warn.all = TRUE for warningifnot()) expression which was not (all) true. See stopifnot 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

stopifnot.with for a data-masked version of this function.

Examples

f1 <- function(call.) stopifnot2(1 == 2, call. = call.)
f2 <- function(call.) f1(call. = call.)
f <- function(call.) f2(call. = call.)

try(f(call. = FALSE))
#> Error : 1 == 2 is not TRUE
try(f(call. = TRUE))
#> Error in f1(call. = call.) : 1 == 2 is not TRUE

try(f(call. = 0))
#> Error in stopifnot2(1 == 2, call. = call.) : 1 == 2 is not TRUE
try(f(call. = 1))
#> Error in f1(call. = call.) : 1 == 2 is not TRUE
try(f(call. = 2))
#> Error in f2(call. = call.) : 1 == 2 is not TRUE

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

try(f())
#> Error in f() : 1 == 2 is not TRUE

try(stopifnot2(all.equal(1, 2)))
#> Error in eval(expr, envir) : 1 and 2 are not equal:
#>   Mean relative difference: 1

warningifnot(1 == 2, 2 == 3)
#> Warning: 1 == 2 is not TRUE
warningifnot(1 == 2, 2 == 3, warn.all = TRUE)
#> Warning: 1 == 2 is not TRUE
#> Warning: 2 == 3 is not TRUE