map applies a function to lists of arguments, similar to Map in
base R, with the argument USE.NAMES set to FALSE.
flatmap performs a recursive map: the return type is always a vector
of some type given by the .default, and if the return value of calling
.f is a vector, it is flattened into the enclosing vector (see
‘Examples’).
transpose is a special map application that concatenates its
inputs to compute a transposed list.
map(.f, ...)flatmap(.f, ..., .default)
flatmap_chr(.f, ...)
vmap(.f, .x, ..., .default)
map_int(.f, ...)
map_lgl(.f, ...)
map_chr(.f, ...)
transpose(...)
an n-ary function where n is the number of further arguments given
lists of arguments to map over in parallel
the default value returned by flatmap for an empty
input
map returns a (potentially nested) list of values resulting
from applying .f to the arguments.
flatmap returns a vector with type given by .default,
or .default, if the input is empty.
transpose returns a list of the element-wise concatenated
input vectors; that is, a “transposed list” of those elements.
flatmap_chr(identity, NULL) # character(0)
flatmap_chr(identity, c('a', 'b')) # [1] "a" "b"
flatmap_chr(identity, list(c('a', 'b'), 'c')) # [1] "a" "b" "c"
transpose(1 : 2, 3 : 4) # [[1]] # [1] 1 3 # # [[2]] # [1] 2 4