purrr (version 1.0.2)

negate: Negate a predicate function so it selects what it previously rejected

Description

Negating a function changes TRUE to FALSE and FALSE to TRUE.

Usage

negate(.p)

Value

A new predicate function.

Arguments

.p

A predicate function (i.e. a function that returns either TRUE or FALSE) specified in one of the following ways:

• A named function, e.g. is.character.

• An anonymous function, e.g. \(x) all(x < 0) or function(x) all(x < 0).

• A formula, e.g. ~ all(.x < 0). You must use .x to refer to the first argument). Only recommended if you require backward compatibility with older versions of R.

Adverbs

This function is called an adverb because it modifies the effect of a function (a verb). If you'd like to include a function created an adverb in a package, be sure to read faq-adverbs-export.

See Also

Other adverbs: auto_browse(), compose(), insistently(), partial(), possibly(), quietly(), safely(), slowly()

Examples

x <- list(x = 1:10, y = rbernoulli(10), z = letters)
x |> keep(is.numeric) |> names()
x |> keep(negate(is.numeric)) |> names()
# Same as
x |> discard(is.numeric)