R: Dynamic dots

dyn-dots {rlang} | R Documentation

## Dynamic dots

### Description

The `...` syntax of base R allows you to:

- Forward arguments from function to function, matching them along the way to function parameters.

- Collect arguments inside data structures, e.g. with `c()` or `list()`.

Dynamic dots offer a few additional features:

1. You can splice arguments saved in a list with the big bang operator `!!!`.

2. You can unquote names by using the bang bang operator `!!` on the left-hand side of `:=`.

3. Trailing commas are ignored, making it easier to copy and paste lines of arguments.

### Add dynamic dots support in your functions

If your function takes dots, adding support for dynamic features is as easy as collecting the dots with `list2()` instead of `list()`.

Other dynamic dots collectors are `dots_list()`, which is more configurable than `list2()`, `vars()` which doesn't force its arguments, and `call2()` for creating calls.

[Package rlang version 0.4.2 Index]