darkslategrey

Should be work with 0.18

Destructuring(or pattern matching) is a way used to extract data from a data structure(tuple, list, record) that mirros the construction. Compare to other languages, Elm support much less destructuring but let's see what it got !

Tuple

myTuple = ("A", "B", "C")
myNestedTuple = ("A", "B", "C", ("X", "Y", "Z"))

darkslategrey

{
    "type": "application",
    "source-directories": [
        "src"
    ],
    "elm-version": "0.19.0",
    "dependencies": {
        "direct": {
            "dillonkearns/elm-graphql": "4.1.0",
            "elm/browser": "1.0.0",

darkslategrey

module Cat exposing (Model(..), Msg(..), getRandomCatGif, gifDecoder, init, main, subscriptions, update, view, viewGif)

import Browser
import Html exposing (..)
import Html.Attributes exposing (..)
import Html.Events exposing (..)
import Http
import Json.Decode exposing (Decoder, field, string)

darkslategrey

module App exposing (Model, Msg(..), init, main, update, view)

-- import Todo.Commands

import Browser
import Cat
import Html exposing (Html, button, div, h1, h2, img, map, text)
import Html.Attributes exposing (..)
import Html.Events exposing (onClick)

darkslategrey

Elm best practices

Style guide

• http://package.elm-lang.org/help/design-guidelines
• http://elm-lang.org/docs/style-guide
• https://github.com/NoRedInk/elm-style-guide
• https://gist.github.com/laszlopandy/c3bf56b6f87f71303c9f
• https://github.com/ohanhi/elm-style-guide

darkslategrey

[greg@poire infra]$ mix test
Compiling 1 file (.ex)

== Compilation error in file test/infra_test.exs ==
** (CompileError) test/infra_test.exs:12: Infra.__struct__/1 is undefined, cannot expand struct Infra
    (ex_unit) expanding macro: ExUnit.Assertions.assert/1
    test/infra_test.exs:12: Scraper.InfraTest."test destruct"/1
    (elixir) lib/code.ex:677: Code.require_file/2
    (elixir) lib/kernel/parallel_compiler.ex:201: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6
[greg@poire infra]$ 

darkslategrey

== Compilation error in file test/infra_test.exs ==
** (UndefinedFunctionError) function Scraper.Infra.__using__/1 is undefined or private
    (infra) Scraper.Infra.__using__([])
    test/infra_test.exs:3: (module)
    (stdlib) erl_eval.erl:670: :erl_eval.do_apply/6
    (elixir) lib/code.ex:677: Code.require_file/2
    (elixir) lib/kernel/parallel_compiler.ex:201: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6

darkslategrey

defmodule Scraper.InfraTest do
  use ExUnit.Case

  doctest Scraper.Infra

  test "greets the world" do
    assert Scraper.Infra.hello() == :world
  end

  test "destruct" do

darkslategrey

defmodule Scraper.Infra do
  alias __MODULE__

  defstruct name: nil

  def bla do
    %Infra{name: "default infra"}
  end

  @moduledoc """

darkslategrey

exported_b
===
inside .env