R: Check for a function argument.

checkArg {BBmisc} | R Documentation

## Check for a function argument.

### Description

Throws exception if checks are not passed. Note that argument is evaluated when checked.

This function is superseded by the package checkmate and might get deprecated in the future. Please

### Usage

    checkArg(x, cl, s4 = FALSE, len, min.len, max.len, choices, subset,
      lower = NA, upper = NA, na.ok = TRUE, formals)

### Arguments

`x` | [any] Argument.
`cl` | [`character`] Class that argument must “inherit” from. If multiple classes are given, `x` must “inherit” from at least one of these. See also argument `s4`.
`s4` | [`logical(1)`] If `TRUE`, use `is` for checking class `cl`, otherwise use `inherits`, which implies that only S3 classes are correctly checked. This is done for speed reasons as calling `is` is pretty slow. Default is `FALSE`.
`len` | [`integer(1)`] Length that argument must have. Not checked if not passed, which is the default.
`min.len` | [`integer(1)`] Minimal length that argument must have. Not checked if not passed, which is the default.
`max.len` | [`integer(1)`] Maximal length that argument must have. Not checked if not passed, which is the default.
`choices` | [any] Discrete number of choices, expressed by a vector of R objects. If passed, argument must be identical to one of these and nothing else is checked.
`subset` | [any] Discrete number of choices, expressed by a vector of R objects. If passed, argument must be identical to a subset of these and nothing else is checked.
`lower` | [`numeric(1)`] Lower bound for numeric vector arguments. Default is `NA`, which means not required.
`upper` | [`numeric(1)`] Upper bound for numeric vector arguments. Default is `NA`, which means not required.
`na.ok` | [`logical(1)`] Is it ok if a vector argument contains NAs? Default is `TRUE`.
`formals` | [`character`] If this is passed, `x` must be a function. It is then checked that `formals` are the names of the (first) formal arguments in the signature of `x`. Meaning `checkArg(function(a, b), formals = "a")` is ok. Default is missing.

### Value

Nothing.

[Package BBmisc version 1.11 Index]