Enumex.Static.Components.Index behaviour (Enumex v1.0.0)

A component that provides functions for working with enum indexes.

Example

defmodule MyApp.Enums do
  use Enumex.Static, components: [Enumex.Static.Components.Index]

  # enum definitions go here
end

Summary

Callbacks

at(enum_name, index, type, default)

Gets an enum id or enum value by index or returns the default.

find_index(enum_name, id_or_value, default)

Gets an enum index by enum id or value or returns the default.

Callbacks

at(enum_name, index, type, default)

@callback at(
  Enumex.Value.enum_name(),
  Enumex.Value.index(),
  type :: :id,
  default :: Enumex.Value.id()
) ::
  Enumex.Value.id()

@callback at(
  Enumex.Value.enum_name(),
  Enumex.Value.index(),
  type :: :value,
  default :: Enumex.Value.id()
) ::
  Enumex.Value.t()

Gets an enum id or enum value by index or returns the default.

Example

iex> MyApp.Enums.elem(:my_enum, 1, :id, :fallback_id)
:first
iex> MyApp.Enums.elem(:my_enum, 100, :id, :fallback_id)
:fallback_id

iex> fallback_value = Enumex.Value.new(MyApp.Enums, :my_enum, :fallback_id, 1000)
iex> MyApp.Enums.elem(:my_enum, 1, fallback_value)
Enumex.Value.new(MyApp.Enums, :my_enum, :first, 1)
iex> MyApp.Enums.elem(:my_enum, 1, :value, fallback_value)
Enumex.Value.new(MyApp.Enums, :my_enum, :first, 1)
iex> MyApp.Enums.elem(:my_enum, 100, fallback_value)
fallback_value
iex> MyApp.Enums.elem(:my_enum, 100, :value, fallback_value)
fallback_value

find_index(enum_name, id_or_value, default)

@callback find_index(
  Enumex.Value.enum_name(),
  id_or_value :: Enumex.Value.id() | Enumex.Value.t(),
  default :: Enumex.Value.index()
) :: Enumex.Value.index()

Gets an enum index by enum id or value or returns the default.

Example

iex> MyApp.Enums.find_index(:my_enum, :first)
1
iex> MyApp.Enums.find_index(:my_enum, :first, 100)
1
iex> MyApp.Enums.find_index(:my_enum, :non_existing)
nil
iex> MyApp.Enums.find_index(:my_enum, :non_existing, 100)
100

iex> first = Enumex.Value.new(MyApp.Enums, :my_enum, :first, 1)
iex> non_existing = Enumex.Value.new(MyApp.Enums, :my_enum, :non_existing, 100)
iex> MyApp.Enums.find_index(:my_enum, first)
1
iex> MyApp.Enums.find_index(:my_enum, first, 100)
1
iex> MyApp.Enums.find_index(:my_enum, non_existing)
nil
iex> MyApp.Enums.find_index(:my_enum, non_existing, 100)
100