Generates Elm types and functions from i18n key/value JSON files
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.

i18n to Elm

Generates Elm types and functions from i18n key/value JSON files.

The tool is meant as an aid if you are using a centralized service to handle the translation of your i18n resources but then need to import the i18n keys/values into your Elm application in a type-safe way.

Note: If you like code that generates code, you might like my other project which turns JSON-schema specs into Elm types+decoders+encoders.


This project requires that you already have elixir and its build tool mix installed, this can be done with brew install elixir or similar.

  • Clone this repository: git clone
  • Build an executable: MIX_ENV=prod mix build
  • An executable, i18n2elm, has now been created in your current working directory.


Run ./i18n2elm for usage instructions.

The executable expects one or more json files with the naming scheme: <language code>_<COUNTRY CODE>.json, e.g. en_US.json or da_DK.json, and that each json file is a simple dictionary of i18n keys and values, for example:

    "Hello": "Hej, {0}. Leder du efter {1}?",
    "Next" : "Næste",
    "No": "Nej",
    "Previous": "Forrige",
    "Yes": "Ja"

A complete example of input and output code can be found in the examples folder.


If we supply i18n2elm with the folder examples/input-i18n-json, containing the two JSON files, da_DK.json:

    "Hello": "Hej, {0}. Leder du efter {1}?",
    "Next" : "Næste",
    "No": "Nej",
    "Previous": "Forrige",
    "Yes": "Ja"

and en_US.json:

    "Hello": "Hello, {0}. Is it {1} you are looking for?",
    "Next" : "Next",
    "No": "No",
    "Previous": "Previous",
    "Yes": "Yes"

it produces the following Elm files, Translations/DaDk.elm:

module Translations.DaDk exposing (daDkTranslations)

import Translations.Ids exposing (TranslationId(..))

daDkTranslations : TranslationId -> String
daDkTranslations tid =
    case tid of
        TidHello hole0 hole1 ->
            "Hej, " ++ hole0 ++ ". Leder du efter " ++ hole1 ++ "?"

        TidNext ->

        TidNo ->

        TidPrevious ->

        TidYes ->

and Translations/EnUs.elm:

module Translations.EnUs exposing (enUsTranslations)

import Translations.Ids exposing (TranslationId(..))

enUsTranslations : TranslationId -> String
enUsTranslations tid =
    case tid of
        TidHello hole0 hole1 ->
            "Hello, " ++ hole0 ++ ". Is it " ++ hole1 ++ " you are looking for?"

        TidNext ->

        TidNo ->

        TidPrevious ->

        TidYes ->

and Translations/Ids.elm:

module Translations.Ids exposing (TranslationId(..))

type TranslationId
    = TidHello String String
    | TidNext
    | TidNo
    | TidPrevious
    | TidYes

and finally Translations/Util.elm:

module Translations.Util exposing (parseLanguage, translate, Language(..))

import Translations.Ids exposing (TranslationId)
import Translations.DaDk exposing (daDkTranslations)
import Translations.EnUs exposing (enUsTranslations)

type Language
    = DA_DK
    | EN_US

parseLanguage : String -> Result String Language
parseLanguage candidate =
    case candidate of
        "da_DK" ->
            Ok DA_DK

        "en_US" ->
            Ok EN_US

        _ ->
            Err <| "Unknown language: '" ++ candidate ++ "'"

translate : Language -> TranslationId -> String
translate language translationId =
        translateFun =
            case language of
                DA_DK ->

                EN_US ->
        translateFun translationId

which contains:

  • The Danish translations as a function, daDkTranslations,
  • the English translations as a function, enUsTranslations,
  • all the translation IDs as a union type, TranslationId,
  • a union type capturing all available languages, Language,
  • a function to parse a string into a Language, parseLanguage, and
  • a function to translate a TranslationId for a given Language into a concrete String value.