Check Function — chk_function • chk

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

Other chk_is: chk_array(), chk_atomic(), chk_data(), chk_is(), chk_matrix(), chk_numeric(), chk_s3_class(), chk_s4_class(), chk_vector(), chk_whole_numeric()

Examples

# chk_function
chk_function(mean)
try(chk_function(1))
#> Error in eval(expr, envir, enclos) : `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