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Check Function

Source: R/chk-function.R
chk_function.Rd

Checks if is a function using

is.function(x) && (is.null(formals) || length(formals(x)) == formals)

Usage

chk_function(x, formals = NULL, x_name = NULL)

vld_function(x, formals = NULL)

Arguments

x

The object to check.

formals

A count of the number of formal arguments.

x_name

A string of the name of object x or NULL.

Value

The chk_ function throws an informative error if the test fails or returns the original object if successful so it can used in pipes.

The vld_ function returns a flag indicating whether the test was met.

Functions

  • vld_function(): Validate Function

See also

is.function() formals()

For more details about the use of this function, please read the article vignette("chk-families").

Other missing_checkers: chk_missing(), chk_not_missing()

Examples

# chk_function
chk_function(mean)
try(chk_function(1))
#> Error in eval(expr, envir) : `1` must be a function.
# vld_function
vld_function(mean)
#> [1] TRUE
vld_function(function(x) x)
#> [1] TRUE
vld_function(1)
#> [1] FALSE
vld_function(list(1))
#> [1] FALSE