Hello, Elm!
Notes
Default Module Declaration
If you forget to add a module declaration at the top of an Elm file, Elm will put everything in a Main
module like so:
module Main exposing (..)
Installing Project Dependencies
In an empty project directory, running elm package install
generates a new elm-package.json
file and adds dependencies for the elm-lang/core
,
elm-lang/html
, and elm-lang/virtual-dom
packages.
However, if an elm-package.json
file already exists in a project directory, then running elm package install
will install all the package dependencies listed in that elm-package.json
file. That means you can download an Elm project and run elm package install
to install all the dependencies of that project in one fell swoop!
To install a specific package, specify the package name like so:
elm-package install elm-lang/html
That downloads the latest version of the elm-lang
package that's compatible with the installed version of Elm. And the elm-package.json
file is automatically updated to include the new package dependency.
To install a specific version of a package, include the version number like so:
elm-package install elm-lang/html 3.0.0
Reactor Options
By default, the Elm reactor fires up on localhost
port 8000
. You can change the address and/or port by specifying --address
and --port
options. For example, here's how to run on the 0.0.0.0
address using port 9000
:
elm reactor --address=0.0.0.0 --port=9000
Code So Far
The code for this video is in the hello-elm
directory found within the video-code
directory of the
code bundle.