mindbat

Keybase proof

I hereby claim:

• I am mindbat on github.
• I am mindbat (https://keybase.io/mindbat) on keybase.
• I have a public key ASBaRUcaZn3Q4UeRJEmEJywORliem0tq5njUwVDmu3QThAo

To claim this, I am signing this object:

mindbat

import Color exposing (..)
import Collage exposing (..)
import Element exposing (Element, image, leftAligned, toHtml)
import Html exposing (Html)
import Keyboard exposing (..)
import Key exposing (..)
import List exposing ((::), all, filter, length)
import Mouse exposing (..)
import Random exposing (Seed, step, initialSeed, int)
import Text exposing (color, fromString, height, monospace)

mindbat

Updated Elm Examples

The Elm examples given in the book (especially from Day Two, forward) are for an older version of Elm. Elm 0.17 changed a lot of things in the language, including eliminating signals and moving a lot of the libraries around.

I’ve translated the Day Two examples from the book to run on Elm 0.18

Examples

Avoiding Callbacks (p. 103)

Elm 0.17+ avoids callbacks using Subscriptions, not Signals: https://gist.github.com/mindbat/7afc23cad8da000e4b26de55986d4eaf

Maintaining State (p. 104-105)

For all three of these examples, we need to swap signals for subscriptions:

• Counting Mouse Moves: https://gist.github.com/mindbat/237066ca2a083bd5bb4e449c82f72a74

mindbat

import Color exposing (..)                                                                                      
import Collage exposing (..)                                                                                    
import Element exposing (..)                                                                                    
                                                                                                                
carBottom = filled black (rect 160 50)                                                                          
carTop = filled black (rect 100 60)                                                                             
tire = filled red (circle 24)                                                                                   
                                                                                                                
car = collage 300 300                                                                                           
       

mindbat

import Html exposing (Html, text, input, div)
import Html.App as App
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import String

main = App.program { init = init,
       view = view, update = update, subscriptions = \_ -> Sub.none }
       
-- Model

mindbat

import Html exposing (Html, text, div)
import Html.App as App
import Mouse exposing (..)

main = App.program { init = init,
       view = view, update = update, subscriptions = subscriptions }
       
-- Model

type alias Model = { x: Int, y : Int }

mindbat

import Html exposing (Html, text, div)
import Html.App as App
import Mouse exposing (..)

main = App.program { init = init,
       view = view, update = update, subscriptions = subscriptions }
       
-- Model

type alias Model = { count: Int }

mindbat

import Html exposing (Html, text, div)
import Html.App as App
import Mouse exposing (..)

main = App.program { init = init,
       view = view, update = update, subscriptions = subscriptions }
       
-- Model

type alias Model = { count: Int }

mindbat

import Html exposing (Html, text, div)
import Html.App as App
import Mouse exposing (..)

main = App.program { init = init,
       view = view, update = update, subscriptions = subscriptions }
       
-- Model

type alias Model = { x: Int, y: Int }

mindbat

safeHead :: [a] -> [a]
safeHead x = take 1 x

safeTail :: [a] -> [a]
safeTail x = drop 1 x

safeInit :: [a] -> [a]
safeInit x = take ((length x) - 1) x

safeLast :: [a] -> [a]