R: Efficient List Transpose

t_list {collapse} | R Documentation

## Efficient List Transpose

### Description

`t_list` turns a list of lists inside-out. The performance is quite efficient regardless of the size of the list.

### Usage

    t_list(l)

### Arguments

`l` | a list of lists. Elements inside the sublists can be heterogeneous, including further lists.

### Value

`l` transposed such that the second layer of the list becomes the top layer and the top layer the second layer. See Examples.

### See Also

`rsplit`, List Processing, Collapse Overview

### Examples

    # Homogenous list of lists
    l <- list(a = list(c = 1, d = 2), b = list(c = 3, d = 4))
    str(l)
    str(t_list(l))

    # Heterogenous case
    l2 <- list(a = list(c = 1, d = letters), b = list(c = 3:10, d = list(4, e = 5)))
    attr(l2, "bla") <- "abc"  # Attributes other than names are preserved
    str(l2)
    str(t_list(l2))

    rm(l, l2)

[Package collapse version 1.7.6 Index]