R: Check that dots are empty

check_dots_empty {rlang} | R Documentation

## Check that dots are empty

### Description

`...` can be inserted in a function signature to force users to fully name the details arguments. In this case, supplying data in `...` is almost always a programming error. This function checks that `...` is empty and fails otherwise.

### Usage

    check_dots_empty(
      env = caller_env(),
      error = NULL,
      call = caller_env(),
      action = abort
    )

### Arguments

`env` | Environment in which to look for `...`.
`error` | An optional error handler passed to `try_fetch()`. Use this e.g. to demote an error into a warning.
`call` | The execution environment of a currently running function, e.g. `caller_env()`. The function will be mentioned in error messages as the source of the error. See the `call` argument of `abort()` for more information.
`action` |

### Details

In packages, document `...` with this standard tag:

     @inheritParams rlang::args_dots_empty

### Examples

    f <- function(x, ..., foofy = 8) {
      check_dots_empty()
      x + foofy
    }

    # This fails because `foofy` can't be matched positionally
    try(f(1, 4))

    # This fails because `foofy` can't be matched partially by name
    try(f(1, foof = 4))

    # Thanks to `...`, it must be matched exactly
    f(1, foofy = 4)

[Package rlang version 1.0.2 Index]