Concatenate contents of multiple iterators into a vector.

concat collects all values from an iterable object, and pastes them end to end into one vector. In other words concat is to as.list.iteror as c is to list.

Usage

concat(obj, mode = "list", n = Inf, ...)

# S3 method for default
concat(obj, mode = "list", n = as.integer(2^31 - 1), ...)

# S3 method for iteror
concat(obj, mode = "list", n = Inf, length.out = Inf, ...)

Arguments

obj: An iteror.
mode: The mode of vector to return.
n: The maximum number of times to call nextOr(obj).
...: passed along to iteror constructor.
length.out: The target size of the output vector (after results have been pasted together). If the iteror ends (or emits n results) before emitting this many elements, the result will be shorter than length.out. If the iterator does not end early, the output will have at least length.out elements, and possibly more, as the entire last chunk will be included.

Value

a vector with mode mode.

Examples


it <- i_apply(icount(), seq_len) # [1], [1, 2], [1, 2, 3], ...
concat(it, n=4, mode="numeric")  # [1, 1, 2, 1, 2, 3, 1, 2, 3, 4]
#>  [1] 1 1 2 1 2 3 1 2 3 4
concat(it, length.out=4, mode="numeric")  # [1, 1, 2, 1, 2, 3, 1, 2, 3, 4]
#> [1] 1 2 3 4 5