dropnests: Drop Redundant List Nesting

In broadcast: Broadcasted Array Operations Like 'NumPy'

Drop Redundant List Nesting

Description

dropnests() drops redundant nesting of a list.
It is the hierarchical equivalent to the dimensional base::drop() function.

Usage

dropnests(x, ...)

## Default S3 method:
dropnests(x, maxdepth = 16L, recurse_all = FALSE, ...)

Arguments

x	a list
...	further arguments passed to or from methods.
maxdepth	a single, positive integer, giving the maximum depth to recurse into the list. The surface-level elements of a list is depth 1. dropnests(x, maxdepth = 1) will return x unchanged.
recurse_all	see broadcast_casting.

Value

A list without redundant nesting.
Attributes are preserved.

See Also

broadcast_casting

Examples

x <- list(
  a = list(list(list(list(1:10)))),
  b = list(1:10)
)

print(x)

dropnests(x)


# recurse_all demonstration ====
x <- list(
  a = list(list(list(list(1:10)))),
  b = data.frame(month.abb, month.name),
  c = data.frame(month.abb),
  d = array(list(1), c(1,1,1))
)

dropnests(x) # by default, recurse_all = FALSE

dropnests(x, recurse_all = TRUE)


# maxdepth demonstration ====
x <- list(
  a = list(list(list(list(1:10)))),
  b = list(1:10)
)
print(x)

dropnests(x) # by default, maxdepth = 16

dropnests(x, maxdepth = 3L)

dropnests(x, maxdepth = 1L) # returns `x` unchanged

broadcast documentation built on Aug. 20, 2026, 9:08 a.m.