An Elixir util module to translate US two letter state codes to state names, and state names to two letter codes.

states.ex

defmodule States do
  @moduledoc """
  A util that allows you to search for the uppercase abbreviation
  of a state by name (case insensitive) or the capitalized name
  of a state by abbreviation (case insensitive).
  """

  @states_to_abbr %{
    "Alabama" => "AL",
    "Alaska" => "AK",
    "Arizona" => "AZ",
    "Arkansas" => "AR",
    "California" => "CA",
    "Colorado" => "CO",
    "Connecticut" => "CT",
    "Delaware" => "DE",
    "District of Columbia" => "DC",
    "Florida" => "FL",
    "Georgia" => "GA",
    "Hawaii" => "HI",
    "Idaho" => "ID",
    "Illinois" => "IL",
    "Indiana" => "IN",
    "Iowa" => "IA",
    "Kansas" => "KS",
    "Kentucky" => "KY",
    "Louisiana" => "LA",
    "Maine" => "ME",
    "Maryland" => "MD",
    "Massachusetts" => "MA",
    "Michigan" => "MI",
    "Minnesota" => "MN",
    "Mississippi" => "MS",
    "Missouri" => "MO",
    "Montana" => "MT",
    "Nebraska" => "NE",
    "Nevada" => "NV",
    "New Hampshire" => "NH",
    "New Jersey" => "NJ",
    "New Mexico" => "NM",
    "New York" => "NY",
    "North Carolina" => "NC",
    "North Dakota" => "ND",
    "Northern Mariana Islands" => "MP",
    "Ohio" => "OH",
    "Oklahoma" => "OK",
    "Oregon" => "OR",
    "Palau" => "PW",
    "Pennsylvania" => "PA",
    "Puerto Rico" => "PR",
    "Rhode Island" => "RI",
    "South Carolina" => "SC",
    "South Dakota" => "SD",
    "Tennessee" => "TN",
    "Texas" => "TX",
    "Utah" => "UT",
    "Vermont" => "VT",
    "Virgin Islands" => "VI",
    "Virginia" => "VA",
    "Washington" => "WA",
    "West Virginia" => "WV",
    "Wisconsin" => "WI",
    "Wyoming" => "WY"
  }

  # Swaps the keys and values of @states_to_abbr
  @abbr_to_states Enum.into(@states_to_abbr, %{}, fn {k, v} -> {v, k} end)

  @doc """
  Takes a state name (case insensitve) and returns a two letter
  abbreviation (uppercase) if a match is found, or nil otherwise.
  """
  def state_to_abbr(state) do
    state = String.downcase(state)

    Enum.find_value(@states_to_abbr, &if(String.downcase(elem(&1, 0)) == state, do: elem(&1, 1)))
  end

  @doc """
  Takes a two letter abbreviation (case insensitve) and returns
  a capitalized state name if found, or nil otherwise.
  """
  def abbr_to_state(abbr) do
    abbr = String.upcase(abbr)

    Enum.find_value(@abbr_to_states, &if(elem(&1, 0) == abbr, do: elem(&1, 1)))
  end
end