Check Argument's Type

Check if an argument has valid type, and if not, generate an error message.

check_type(
  x,
  valid,
  name = NULL,
  general = NULL,
  specific = NULL,
  supplement = NULL,
  ...
)

Arguments

x: The argument to check, which can be any object.
valid: A character vector which contains the valid types.
name: A single character which gives the argument's name. The name is used in the error message. By default, the name of the argument passed to argument x is captured automatically.
general: Optional. A single character which is used to give a general statement of the error incurred. By default, this is generated automatically.
specific: Optional. A single character which gives a detailed description of the error. glue::glue() syntax can be used, see "Examples" section. By default, this is generated automatically.
supplement: Optional. A (named) character vector which gives some additional information about the error. The names are used to create bullets, see throw(). By default, this is left empty.
...: Optional. Additional arguments which can be retrieved with tryCatch().

Value

returns an invisible NULL if the argument is valid, or generates an error message.

Examples

# argument to check
arg <- 10

# returns silently if the argument has valid type
check_type(arg, "double")

if (FALSE) {
check_type(arg, "character")

# specify argument's name
check_type(arg, "character", name = "x")

# specify argument `specific` with `glue::glue()` syntax
specific <- "`{name}`'s type is {feature}, which is wrong."
check_type(arg, "character", specific = specific)

# specify argument `supplement`
supplement <- c("You're wrong.", i = "Check your code.")
check_type(arg, "character", supplement = supplement)

# turn off `specific`
check_type(arg, "character", specific = character())
}

# add and retrieve additional argument
tryCatch(
  {check_type(arg, "character", your_arg = "your data")},
  error = function(e) e$your_arg
)
#> [1] "your data"

Arguments

Value

See also

Examples