check_input_class: Check the class of an function input to a parent function
In edwardlavender/prettyGraphics: Pretty Graphics with R

check_input_class

R Documentation

Check the class of an function input to a parent function

Description

This function checks that the class of an input to a parent function is appropriate. If not, the function either produces a helpful error message or returns a warning.

Usage

check_input_class(
  arg,
  input,
  if_class = NULL,
  to_class,
  type = "stop",
  coerce_input
)

Arguments

`arg`	A character string which defines the argument of the parent function.
`input`	The input to an argument of a parent function.
`if_class`	(optional) A character vector of classes of object. If supplied, the function will only proceed to check the class of the object if the `class(input)` is one of `if_class`. This is useful if `check_input_class()` is implemented in a loop.
`to_class`	The required class of the input.
`type`	A character which specifies whether to return an error (`"stop"`) or a warning ("warning").
`coerce_input`	A function used to coerce `input` to the correct object type, if `type = "warning"`.

Value

The function checks the class of the input. If the class is not the same as required by the parent function (i.e., as specified by class), the function returns a helpful error message, or a warning and an object whose class has been coerced to the correct class.