R: Is object a node or pairlist?

is_pairlist {rlang} | R Documentation

## Is object a node or pairlist?

### Description

- `is_pairlist()` checks that `x` has type `pairlist` or `NULL`. `NULL` is treated as a pairlist because it is the terminating node of pairlists and an empty pairlist is thus the `NULL` object itself.

- `is_node()` checks that `x` has type `pairlist`.

In other words, `is_pairlist()` tests for the data structure while `is_node()` tests for the internal type.

### Usage

    is_pairlist(x)

    is_node(x)

### Arguments

`x` | Object to test.

### See Also

`is_lang()` tests for language nodes.

[Package rlang version 0.1.6 Index]