zwilias/elm-toml

Parse and decode TOML in Elm


License
BSD-3-Clause
Install
elm-package install zwilias/elm-toml 1.0.0

Documentation

elm-toml

Parsing TOML in Elm

Build Status

This library attempts to model TOML in Elm, providing a means to parse a TOML document into an Elm datastructure.

Usage

Let's say we have a TOML document like so:

################################################################################
## This is my very important settings document                                ##
################################################################################

org.name = "Test org"
org.created = 2017-08-11

z-index = 12321

[[user]]
name = "Ilias"

[[user]]
name = "Alice"

[[user]]
name = "Fido"

We could model an equivalent Elm datastructure like so:

import Toml.Calendar as Calendar


type alias User =
    { name : String }
    

type alias Organisation =
    { name : String
    , created : Calendar.Date
    }


type Settings =
    { zIndex : Int
    , org : Organisation
    , users : List User
    }

Now, writing some decoder for this should be pretty straightforward, too:

import Toml.Decode as Decode exposing (Decoder)


user : Decoder e User
user =
    Decode.map User (Decode.field "name" Decode.string)
    
    
organisation : Decoder e Organisation
organisation =
    Decode.map2 Organisation
        (Decode.field "name" Decode.string)
        (Decode.field "created" Decode.localDate)
        
        
settings : Decoder e Settings
settings =
    Decode.map3 Settings
        (Decode.field "z-index" Decode.int)
        (Decode.field "org" organisation)
        (Decode.field "users" (Decode.list user))

And finally, we could run the settings decoder against our document using Toml.Decode.decodeString settings document.

Contributing

Code in this project is formatted with elm-format. The currently used version is specified in the package.json file. Verifying formatting is part of CI.

Examples in the documentation are verified using elm-verify-examples.

Unit tests are available in the tests directory and can be executed using elm-test.

To run all tests locally:

$ npm i # Install all dependencies
$ npm test # Run tests

All contributions are welcome. Opening an issue and starting a conversation before delving into the code is very much appreciated! Collaboration requires communication.

License

Licensed with love under BSD-3. Refer to the LICENSE file for more info.