components {valaddin}

Decompose a firmly applied function

Description

Decompose a firmly applied function (i.e., a function created by firmly):

• firm_core extracts the underlying “core” function—the function that is called when all arguments are valid.

• firm_checks extracts the checks.

• firm_error extracts the subclass of the error condition that is signaled when an input validation error occurs.

• firm_args extracts the names of arguments whose presence is to be checked, i.e., those specified by the .warn_missing switch of firmly.

Usage

firm_core(x)

firm_checks(x)

firm_error(x)

firm_args(x)

Arguments

x

Object to decompose.

Value

If x is a firmly applied function:

• firm_core returns a function.

• firm_checks returns a data frame with components expr (language), env (environment), string (character), msg (character).

• firm_error returns a character vector.

• firm_args returns a character vector.

In the absence of the component to be extracted, these functions return NULL.

See Also

firmly

Examples

f <- function(x, y, ...) NULL
f_fm <- firmly(f, ~is.numeric, list(~x, ~y - x) ~ {. > 0})

identical(firm_core(f_fm), f)                  # [1] TRUE
firm_checks(f_fm)                              # 4 x 4 data frame
firm_error(f_fm)                               # [1] "simpleError"
firm_args(f_fm)                                # NULL
firm_args(firmly(f_fm, .warn_missing = "y"))   # [1] "y"