Update for 0.17

elm-package.json

@@ -1,6 +1,6 @@
 {
-    "version": "2.0.0",
-    "summary": "an experimental library for easily updating nested records",
+    "version": "2.0.1",
+    "summary": "an experimental library for working with records",
     "repository": "https://github.com/evancz/focus.git",
     "license": "BSD3",
     "source-directories": [
@@ -10,7 +10,8 @@
         "Focus"
     ],
     "dependencies": {
-        "elm-lang/core": "2.0.0 <= v < 4.0.0"
+        "elm-lang/core": "4.0.0 <= v < 5.0.0",
+        "elm-lang/html": "1.0.0 <= v < 2.0.0"
     },
-    "elm-version": "0.15.0 <= v < 0.17.0"
+    "elm-version": "0.17.0 <= v < 0.18.0"
 }

examples/Physics.elm

@@ -0,0 +1,63 @@
+import Focus exposing (..)
+import Html exposing (..)
+
+
+
+-- OBJECTS
+
+
+type alias Object =
+  { position : Point
+  , velocity : Point
+  }
+
+
+type alias Point =
+  { x : Float
+  , y : Float
+  }
+
+
+
+-- DO STUFF
+
+
+main : Html msg
+main =
+  text (toString (step 1.5 object))
+
+
+object : Object
+object =
+  Object (Point 3 4) (Point 1 1)
+
+
+step : Float -> Object -> Object
+step dt object =
+  object
+    |> update (position => x) (\px -> px + object.velocity.x * dt)
+    |> update (position => y) (\py -> py + object.velocity.y * dt)
+
+
+
+-- FOCI
+
+
+x : Focus { r | x:a } a
+x =
+  create .x (\f r -> { r | x = f r.x })
+
+
+y : Focus { r | y:a } a
+y =
+  create .y (\f r -> { r | y = f r.y })
+
+
+position : Focus { r | position : a } a
+position =
+  create .position (\f r -> { r | position = f r.position })
+
+
+velocity : Focus { r | velocity : a } a
+velocity =
+  create .velocity (\f r -> { r | velocity = f r.velocity })

src/Focus.elm

@@ -1,4 +1,4 @@
-module Focus (Focus, get, set, update, (=>), create) where
+module Focus exposing (Focus, get, set, update, (=>), create)
 {-| Our goal is to update a field deep inside some nested records. For example,
 if we want to add one to `object.physics.velocity.x` or set it to zero, we would
 be writing code like this: