Create a deferred list — deflist • deflist

A read-only list that retrieves elements with a function call. The deferred list is useful for handling large datasets where elements are computed on-demand.

Usage

deflist(
  fun,
  len = 1,
  names,
  memoise = FALSE,
  cache = c("memory", "file"),
  cachedir = NULL
)

Arguments

fun: A function that is used to retrieve elements.
len: Integer, the length of the list (default is 1).
names: Character vector, an optional set of names, one per element.
memoise: Logical, whether to memoise the function to speed up repeated element access (default is FALSE).
cache: Character, use an in-memory or filesystem cache if memoise is TRUE (default is "memory").
cachedir: Character, the file path to the cache (default is NULL).

Value

An object of class "deflist" representing the deferred list.

Details

The deferred list is created using the provided function, length, names, and caching options. The list is read-only, and elements are retrieved using the provided function.

Examples

# Create a deferred list of squares
square_fun <- function(i) i^2
square_deflist <- deflist(square_fun, len = 5)
print(square_deflist)
#> deflist:  5  elements. 
#> memoised:  FALSE 
cat("First element of the list:", square_deflist[[1]], "\n")
#> First element of the list: 1