Credence.Pattern.PreferEnumSlice (credence v0.7.1)

Readability rule: flags Enum.drop/2 followed by Enum.take/2 and rewrites it to Enum.slice/3.

Enum.drop(list, start) |> Enum.take(len) keeps elements [start, start+len), which is exactly Enum.slice(list, start, len) — but only when both start and len are non-negative. With a negative start, Enum.drop counts from the end while Enum.slice's start indexes from the end differently; with a negative len, Enum.take keeps the last len while Enum.slice rejects a negative length. So the rule fires only when both amounts are non-negative integer literals — a variable amount could be negative at runtime and is not rewritten.

Bad

Enum.drop(list, 5) |> Enum.take(10)
Enum.take(Enum.drop(list, 5), 10)

Good

Enum.slice(list, 5, 10)

Not flagged

Enum.drop(list, start) |> Enum.take(len)   # variable amounts (could be negative)
Enum.drop(list, -1) |> Enum.take(2)        # negative drop
Enum.drop(list, 1) |> Enum.take(-2)        # negative take