map_struct: Apply a function to each element of a vector

In terminological/ggrrr: Addressing Annoyances and Irritations

Apply a function to each element of a vector

Description

The map functions transform their input by applying a function to each element of a list or atomic vector and returning an object of the same length as the input.

• map() always returns a list. See the modify() family for versions that return an object of the same type as the input.

• map_lgl(), map_int(), map_dbl() and map_chr() return an atomic vector of the indicated type (or die trying). For these functions, .f must return a length-1 vector of the appropriate type.

• map_vec() simplifies to the common type of the output. It works with most types of simple vectors like Date, POSIXct, factors, etc.

• walk() calls .f for its side-effect and returns the input .x.

Usage

map_struct(.x, .f, ..., .progress = FALSE)

Arguments

.x	A list or atomic vector.
.f	A function, specified in one of the following ways: A named function, e.g. mean. An anonymous function, e.g. ⁠\(x) x + 1⁠ or function(x) x + 1. A formula, e.g. ~ .x + 1. You must use .x to refer to the first argument. Only recommended if you require backward compatibility with older versions of R. A string, integer, or list, e.g. "idx", 1, or list("idx", 1) which are shorthand for ⁠\(x) pluck(x, "idx")⁠, ⁠\(x) pluck(x, 1)⁠, and ⁠\(x) pluck(x, "idx", 1)⁠ respectively. Optionally supply .default to set a default value if the indexed element is NULL or does not exist.
...	Additional arguments passed on to the mapped function. We now generally recommend against using ... to pass additional (constant) arguments to .f. Instead use a shorthand anonymous function: # Instead of x |> map(f, 1, 2, collapse = ",") # do: x |> map(\(x) f(x, 1, 2, collapse = ",")) This makes it easier to understand which arguments belong to which function and will tend to yield better error messages.
.progress	Whether to show a progress bar. Use TRUE to turn on a basic progress bar, use a string to give it a name, or see progress_bars for more details.

Value

a 'struct_list'

terminological/ggrrr documentation built on June 15, 2024, 6:35 a.m.