R: Unlistable Lists

is_unlistable {collapse} | R Documentation

## Unlistable Lists

### Description

A (nested) list with atomic objects in all final nodes of the list-tree is unlistable - checked with `is_unlistable`.

### Usage

    is_unlistable(l, DF.as.list = FALSE)

### Arguments

`l` | a list.
`DF.as.list` | logical. `TRUE` treats data frames like (sub-)lists; `FALSE` like atomic elements.

### Details

`is_unlistable` with `DF.as.list = TRUE` is defined as `all(rapply(l, is.atomic))`, whereas `DF.as.list = FALSE` yields checking using `all(unlist(rapply2d(l, function(x) is.atomic(x) || is.list(x)), use.names = FALSE))`, assuming that data frames are lists composed of atomic elements. If `l` contains data frames, the latter can be a lot faster than applying `is.atomic` to every data frame column.

### Value

`logical(1)` - `TRUE` or `FALSE`.

### See Also

`ldepth`, `has_elem`, List Processing, Collapse Overview

### Examples

    l <- list(1, 2, list(3, 4, "b", FALSE))
    is_unlistable(l)
    l <- list(1, 2, list(3, 4, "b", FALSE, e ~ b))
    is_unlistable(l)

[Package collapse version 1.8.6 Index]