swiss v2.12.2 Swiss.Enum View Source

Helper functions for dealing with Enumerables.

Link to this section Summary

Functions

find_both(enumerable, fun)

Finds an element and its index in enumerable for which fun returns true.

find_by(enumerable, default \\ nil, key, value)

Finds the first element in enumerable where its key equals value. Returns default if not found.

find_by!(enumerable, key, value)

Finds the first element in enumerable where its key equals value. Raises if not found.

group_by_single(enum, key_fn, value_fn \\ fn x -> x end)

Same as Enum.group_by/3 but expects each group to have a single element, and therefore returns only that element per key, instead of a list.

thru(enum, cb)

Applies cb to all elements in enum, ignores the return and returns enum.

Link to this section Functions

find_both(enumerable, fun)

Finds an element and its index in enumerable for which fun returns true.

Examples

iex> Swiss.Enum.find_both([42, 44, 46], fn num -> num == 44 end)
{44, 1}

iex> Swiss.Enum.find_both([42, 44, 46], fn num -> num == 45 end)
{nil, nil}

find_by(enumerable, default \\ nil, key, value)

find_by(Enumerable.t(), any(), any(), any()) :: any()

Finds the first element in enumerable where its key equals value. Returns default if not found.

Examples

iex> Swiss.Enum.find_by([%{life: 11}, %{life: 42}], :life, 42)
%{life: 42}

iex> Swiss.Enum.find_by([%{life: 11}, %{life: 42}], :wat, 42)
nil

iex> Swiss.Enum.find_by([%{life: 11}, %{life: 42}], 42, :wat, 42)
42

iex> Swiss.Enum.find_by([%Swiss.TestStruct{life: 42}], :life, 42)
%Swiss.TestStruct{life: 42}

find_by!(enumerable, key, value)

find_by!(Enumerable.t(), any(), any()) :: any()

Finds the first element in enumerable where its key equals value. Raises if not found.

Examples

iex> Swiss.Enum.find_by!([%{life: 11}, %{life: 42}], :life, 42)
%{life: 42}

iex> Swiss.Enum.find_by!([%{life: 11}, %{life: 42}], :wat, 42)
** (Swiss.Enum.KeyValueError) key :wat with value 42 not found in: [%{life: 11}, %{life: 42}]

group_by_single(enum, key_fn, value_fn \\ fn x -> x end)

Same as Enum.group_by/3 but expects each group to have a single element, and therefore returns only that element per key, instead of a list.

Examples

iex> Swiss.Enum.group_by_single(
...>   [%{k: "life", v: 42}, %{k: "death", v: 13}, %{k: "ooo", v: 0}],
...>   & &1.k,
...>   & &1.v
...> )
%{"life" => 42, "death" => 13, "ooo" => 0}

thru(enum, cb)

thru(Enumerable.t(), function()) :: Enumerable.t()

Applies cb to all elements in enum, ignores the return and returns enum.

Examples

iex> Swiss.Enum.thru([1, 2, 3], fn a -> a + 1 end)
[1, 2, 3]