attr_getter: Create an attribute getter function

In tidyverse/purrr: Functional Programming Tools

Create an attribute getter function

Description

attr_getter() generates an attribute accessor function; i.e., it generates a function for extracting an attribute with a given name. Unlike the base R attr() function with default options, it doesn't use partial matching.

Usage

attr_getter(attr)

Arguments

attr	An attribute name as string.

See Also

pluck()

Examples

# attr_getter() takes an attribute name and returns a function to
# access the attribute:
get_rownames <- attr_getter("row.names")
get_rownames(mtcars)

# These getter functions are handy in conjunction with pluck() for
# extracting deeply into a data structure. Here we'll first
# extract by position, then by attribute:
obj1 <- structure("obj", obj_attr = "foo")
obj2 <- structure("obj", obj_attr = "bar")
x <- list(obj1, obj2)

pluck(x, 1, attr_getter("obj_attr"))  # From first object
pluck(x, 2, attr_getter("obj_attr"))  # From second object

tidyverse/purrr documentation built on Nov. 7, 2023, 7:33 a.m.