Require usage of !any(x) over all(!x), !all(x) over any(!x)

any(!x) is logically equivalent to !all(x); ditto for the equivalence of all(!x) and !any(x). Negating after aggregation only requires inverting one logical value, and is typically more readable.

Usage

outer_negation_linter()

See also

linters for a complete list of linters available in lintr.

Tags

best_practices, efficiency, readability

Examples

# will produce lints
lint(
  text = "all(!x)",
  linters = outer_negation_linter()
)
#> <text>:1:1: warning: [outer_negation_linter] !any(x) is better than all(!x). The former applies negation only once after aggregation instead of many times for each element of x.
#> all(!x)
#> ^~~~~~~

lint(
  text = "any(!x)",
  linters = outer_negation_linter()
)
#> <text>:1:1: warning: [outer_negation_linter] !all(x) is better than any(!x). The former applies negation only once after aggregation instead of many times for each element of x.
#> any(!x)
#> ^~~~~~~

# okay
lint(
  text = "!any(x)",
  linters = outer_negation_linter()
)
#> ℹ No lints found.

lint(
  text = "!all(x)",
  linters = outer_negation_linter()
)
#> ℹ No lints found.