@spec to_keyword(list(), (atom() -> term()) | term()) :: keyword()

Converts a list to a keyword list, setting the value to default_value. The list can be a regular list, a keyword list (which is a no-op), or a list that's a mix of terms and keywords (e.g., [:a, :b, c: 3, d: 4]). The default value can be a term or a function that accepts a key and is expected to return a value.

iex> Moar.List.to_keyword([:a, :b, c: 3, d: 4])
[a: nil, b: nil, c: 3, d: 4]

iex> Moar.List.to_keyword([:a, :b, c: 3, d: 4], 1)
[a: 1, b: 1, c: 3, d: 4]

iex> Moar.List.to_keyword([:ant, :bird, cheetah: 7, dingo: 5], fn key -> key |> to_string() |> String.length() end)
[ant: 3, bird: 4, cheetah: 7, dingo: 5]

@spec to_sentence([any()], (any() -> binary())) :: binary()

Converts a list to a comma-separated list that has "and" before the last item. The items in the list are converted to strings via a mapper function, which defaults to Kernel.to_string/1.

iex> Moar.List.to_sentence([])
""

iex> Moar.List.to_sentence(["ant"])
"ant"

iex> Moar.List.to_sentence(["ant", :bat])
"ant and bat"

iex> Moar.List.to_sentence(["ant", :bat, "cat"])
"ant, bat, and cat"

iex> Moar.List.to_sentence(["ant", "bat", "cat"], &String.upcase/1)
"ANT, BAT, and CAT"

@spec unwrap!(any() | [any()]) :: any()

Returns the argument if it is not a list. If it is a list, returns the only item in the list, or raises if the list is empty or has more than one item.

iex> Moar.List.unwrap!([5])
5

iex> Moar.List.unwrap!(5)
5

iex> Moar.List.unwrap!([])
** (FunctionClauseError) no function clause matching in Moar.List.unwrap!/1

iex> Moar.List.unwrap!([5, 9])
** (FunctionClauseError) no function clause matching in Moar.List.unwrap!/1