R: Type predicates

type-predicates {purrr} | R Documentation

## Type predicates

### Description

These type predicates aim to make type testing in R more consistent. They are wrappers around `typeof`, so operate at a level beneath S3/S4 etc.

### Usage

    is_list(x)

    is_atomic(x)

    is_vector(x)

    is_numeric(x)

    is_integer(x)

    is_double(x)

    is_character(x)

    is_logical(x)

    is_null(x)

    is_function(x)

### Arguments

`x` | object to be tested.

### Details

Compare to base R functions:

- Unlike `is.atomic()`, `is_atomic()` does not return `TRUE` for `NULL`.

- Unlike `is.vector()`, `is_vector()` test if an object is an atomic vector or a list. `is.vector` checks for the presence of attributes (other than name).

- `is_numeric()` is not generic so, (e.g.) dates and date times are `TRUE`, not `FALSE`.

- `is_function()` returns `TRUE` only for regular functions, not special or primitive functions.

### See Also

bare-type-predicates scalar-type-predicates

[Package purrr version 0.2.2 Index]