Downloaded 14 times
![class Pos {
var x: Int = _
var y: Int = _
}
class Entity {
var pos: Pos = _
var embubbled: Boolean = _
}
class Game {
var player1, player2: Entity = _
var monsters: ListBuffer[Entity] = _
var bubbles: ListBuffer[Bubble] = _
var score: Int = _
}](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-10-2048.jpg)
![case class Pos(x: Int, y: Int)
sealed trait Entity { def pos: Pos }
case class Monster(pos: Pos, embubbled: Boolean)
extends Entity
case class Player(pos: Pos, lives: Int)
extends Entity
case class Bubble(pos: Pos) extends Entity
case class Game(
player1: Player,
player2: Option[Player]
monsters: List[Monster],
bubbles: List[Bubble],
score: Int)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-16-2048.jpg)
![data Player = Player { _playerPos :: Pos
, _lives :: Int }
data Pos = Pos { _x :: Int, _y :: Int }
data Monster = Monster { _monsterPos :: Pos
, _embubbled :: Bool }
data Bubble = Bubble { _bubblePos :: Pos }
data Game = Game
{ _player1 :: Player
, _monsters :: [Monster]
, _bubbles :: [Bubble]
, _score :: Int
}
makeLenses ''Player
makeLenses ''Pos
makeLenses ''Monster
makeLenses ''Bubble
makeLenses ''Game](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-38-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
view monsters g
Lens
(1,2) (33,88)(44,102)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-39-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
toListOf (monsters.each) g
Traversal
(1,2) (33,88)(44,102)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-40-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
toListOf
(monsters.each.monsterPos) g
Traversal
(1,2) (44,102) (33,88)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-41-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
toListOf
(monsters.each.monsterPos.x) g
Traversal
1, 44, 33](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-42-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
set
(monsters.each.monsterPos.x)
11 g
(11,2) (11,88)(11,102)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-43-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
over
(monsters.each.monsterPos.x)
(+1) g
(2,2) (34,88)(45,102)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-44-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
monsters.each.monsterPos.x .~ 11
$ g
(11,2) (11,88)(11,102)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-45-2048.jpg)
![import Control.Lens
g = Game (Player (Pos 33 22) 3)
[ Monster (Pos 1 2) True
, Monster (Pos 44 102) False
, Monster (Pos 33 88) False
] [] 1000
monsters.each.monsterPos.x %~ (+1)
$ g
(2,2) (34,88)(45,102)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-46-2048.jpg)
![(def users [{:name "Linda" :age 30}
{:name "Tom" :age 20}])
(get-in users [0 :name])
”Linda”
(update-in users [1 :age] + 1)
[{:name ”Linda" :age 30}
{:name ”Tom" :age 21}]
(assoc-in users [1 :name] "Sparkles")
[{:name ”Linda" :age 30}
{:name ”Sparkles" :age 20}])](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-51-2048.jpg)
![[{"name": "Linda", "age": 30},
{"name": "Tom", "age": 20}]
.[0].name
“Linda”
.[].age += 1
[{"name": "Linda", "age": 31},
{"name": "Tom", "age": 21}]
.[1].name |= "Sparkles”
[{"name": "Linda", "age": 30},
{"name": ”Sparkles", "age": 20}]](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-52-2048.jpg)
![<people>
<person>
<name>Linda</name>
<age>30</age>
</person
<person>
<name>Tom</name>
<age>20</age>
</person>
</people>
/people/person[1]/name
<name>Linda</name>
/people/person/age
<age>30</age>
<age>20</age>](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-53-2048.jpg)
![[1,2,3]*.multiply(2)
[2,4,6]](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-54-2048.jpg)
![class Lens[S,A]
class Traversal[S,A]
class Prism[S,A]
class Iso[S,A]
class Fold[S,A]
class Getter[S,A]
class Setter[S,A]
class Optional[S,A]](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-62-2048.jpg)
![import monocle.macros.GenLens
case class Pos(x: Int, y: Int)
object Pos {
val x: Lens[Pos,Int] = GenLens[Pos](_.x)
val y: Lens[Pos,Int] = GenLens[Pos](_.y)
}](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-63-2048.jpg)
![Goggles syntax
import goggles._
get"$g.monsters[1].embubbled”
set"$g.monsters*.pos.x" := 55555
set"$g.player2?.lives" ~= (_ + 3)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-68-2048.jpg)
![val g: Game
val posL: Lens[Monster, Pos]
get"${g}.monsters*.${posL}.x"](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-69-2048.jpg)
![".monsters*." ".x"
Hole Name(monsters) Each Hole Name(x)
List[String]
AST
""](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-71-2048.jpg)
![trait Parse[T, Arg, A] {
def apply(state: ParseState[T,Arg]):
(Either[GogglesError[T],A],
ParseState[T,Arg])
}
Interpreter monad](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-72-2048.jpg)
![(List[Arg], List[Info])
(Either[Error,A], List[Arg], List[Info])
Interpreter monad](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-73-2048.jpg)
![Info:
AST:
Tree:
”$game", Unit, Game, Iso, Iso
const(game).composeGetter(Getter(_.monsters))
".monsters", Game, List[Monster], Getter, Getter
${posL}Args:
Name(monsters)
Each Hole Name(x)](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-76-2048.jpg)
![Info:
AST:
Each
Hole Name(x)
Tree:
”$game", Unit, Game, Iso, Iso
const(game).composeGetter(Getter(_.monsters))
.composeTraversal(Each.each)
".monsters", Game, List[Monster], Getter, Getter
"*", List[Monster], ??????, Traversal, Fold
${posL}Args:
How to learn the type of values?](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-77-2048.jpg)
![Info:
AST:
Each
Hole Name(x)
Tree:
”$game", Unit, Game, Iso, Iso
const(game).composeGetter(Getter(_.monsters))
.composeTraversal(Each.each)
".monsters", Game, List[Monster], Getter, Getter
"*", List[Monster], Monster, Traversal, Fold
${posL}Args:
typecheck(
q"implicitly[
_root_.monocle.function.
Each[List[Monster], _]]")
Typechecking will fill it in for us](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-78-2048.jpg)
![Info:
AST:
Each
Hole Name(x)
Tree:
”$game", Unit, Game, Iso, Iso
const(game).composeGetter(Getter(_.monsters))
.composeTraversal(Each.each)
".monsters", Game, List[Monster], Getter, Getter
"*", List[Monster], Monster, Traversal, Fold
${posL}Args:
Got it!](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-79-2048.jpg)
![${posL}
Args:
Info:
AST:
Hole
Name(x)
Tree:
”$game", Unit, Game, Iso, Iso
const(game).composeGetter(Getter(_.monsters))
.composeTraversal(Each.each)
.composeLens(posL)
".monsters", Game, List[Monster], Getter, Getter
"*", List[Monster], Monster, Traversal, Fold
”$posL", Monster, Pos, Lens, Fold](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-80-2048.jpg)
![Info:
AST:
Name(x)
Tree:
”$game", Unit, Game, Iso, Iso
const(game).composeGetter(Getter(_.monsters))
.composeTraversal(Each.each)
.composeLens(posL)
.composeGetter(Getter(_.x))
".monsters", Game, List[Monster], Getter, Getter
"*", List[Monster], Monster, Traversal, Fold
”$posL", Monster, Pos, Lens, Fold
".x", Pos, Int, Getter, Fold](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-81-2048.jpg)
![Info:
Error: NameNotFound("BLAH", Int)
”$game", Unit, Game, Iso, Iso
".monsters", Game, List[Monster], Getter, Getter
"*", List[Monster], Monster, Traversal, Fold
”$posL", Monster, Pos, Lens, Fold
".x", Pos, Int, Getter, Fold
get”$g.monsters*.$posL.x.BLAH"](https://image.slidesharecdn.com/lensesforthemasses-170508073239/75/Lenses-for-the-masses-introducing-Goggles-82-2048.jpg)
More Related Content
Similar to Lenses for the masses - introducing Goggles
Lenses for the masses - introducing Goggles
- 1. LENSES FOR THE MASSES …introducin gGoggles @KenScambler λ
- 8.
- 10. class Pos { varx: Int = _ var y: Int = _ } class Entity { var pos: Pos = _ var embubbled: Boolean = _ } class Game { var player1, player2: Entity = _ var monsters: ListBuffer[Entity] = _ var bubbles: ListBuffer[Bubble] = _ var score: Int = _ }
- 11.
- 12.
- 13. “Assignment… leads usinto a thicket of difficult conceptual issues.” Ch. 3.1.2
- 14. “Nevertheless… it isa powerful technique for maintaining a modular design.” Ch. 3.1.2
- 15. • Tracks stateover time • Local change instantly propagates without external knowledge or orchestration • Efficient • Can’t reason locally • Can’t substitute expressions with result • Spooky action at a distance • Disadvantages are infectious • Forget about concurrency • Hard to isolate things for testing • Can’t fit behaviour patterns in your head GOOD BAD Mutable?
- 16. case class Pos(x:Int, y: Int) sealed trait Entity { def pos: Pos } case class Monster(pos: Pos, embubbled: Boolean) extends Entity case class Player(pos: Pos, lives: Int) extends Entity case class Bubble(pos: Pos) extends Entity case class Game( player1: Player, player2: Option[Player] monsters: List[Monster], bubbles: List[Bubble], score: Int)
- 17.
- 18. game.copy(player = game.player.copy(pos = game.player.pos.copy(x= game.player.pos.x + 10 ) ) ) 218
- 19. • Referential transparency •Local reasoning • Equational reasoning • Easily testable • Need to manually orchestrate position • Need to know path information within world • Need to know how to recreate in the world • Need to write a lot of stuff • Repetitive, hard to read • Inefficient Immutable? GOOD BAD
- 20. Apparently it isterrible at a bunch of common problems 😳 FP is supposed to be all about modularity!
- 22. set: S A S get: S A LENS
- 23. (X,Y) e => e.pos e=> p => e.copy(pos = p) LENS pos
- 24. (X,Y) p => x p=> x2 => p.copy(x = x2) LENS Int x
- 25.
- 26.
- 27. 208 (playerL ∘ posL∘ xL).get(game)
- 28. 218 (playerL ∘ posL∘ xL).modify(game)(_ + 10)
- 29. setBack: A S maybeGet: S S | A PRISM
- 30. { case m: Player=> Right(m) case e => Left(e) } PRISM asPlayer
- 31.
- 32.
- 33.
- 34.
- 35. (monsters ∘ each∘ embubbled).getList(game) false true false false falsefalse false
- 36.
- 37. Optics libraries are toohard to learn 2
- 38. data Player =Player { _playerPos :: Pos , _lives :: Int } data Pos = Pos { _x :: Int, _y :: Int } data Monster = Monster { _monsterPos :: Pos , _embubbled :: Bool } data Bubble = Bubble { _bubblePos :: Pos } data Game = Game { _player1 :: Player , _monsters :: [Monster] , _bubbles :: [Bubble] , _score :: Int } makeLenses ''Player makeLenses ''Pos makeLenses ''Monster makeLenses ''Bubble makeLenses ''Game
- 39. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 view monsters g Lens (1,2) (33,88)(44,102)
- 40. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 toListOf (monsters.each) g Traversal (1,2) (33,88)(44,102)
- 41. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 toListOf (monsters.each.monsterPos) g Traversal (1,2) (44,102) (33,88)
- 42. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 toListOf (monsters.each.monsterPos.x) g Traversal 1, 44, 33
- 43. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 set (monsters.each.monsterPos.x) 11 g (11,2) (11,88)(11,102)
- 44. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 over (monsters.each.monsterPos.x) (+1) g (2,2) (34,88)(45,102)
- 45. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 monsters.each.monsterPos.x .~ 11 $ g (11,2) (11,88)(11,102)
- 46. import Control.Lens g =Game (Player (Pos 33 22) 3) [ Monster (Pos 1 2) True , Monster (Pos 44 102) False , Monster (Pos 33 88) False ] [] 1000 monsters.each.monsterPos.x %~ (+1) $ g (2,2) (34,88)(45,102)
- 48. class ( Choice p, Corepresentablep, Comonad (Corep p), Traversable (Corep p), Strong p, Representable p, Monad (Rep p), MonadFix (Rep p), Distributive (Rep p), Costrong p, ArrowLoop p, ArrowApply p, ArrowChoice p, Closed p) => Conjoined p where ...
- 49. Boring problems demandboring solutions!
- 50. Easy solutions are toolimited 3
- 51. (def users [{:name"Linda" :age 30} {:name "Tom" :age 20}]) (get-in users [0 :name]) ”Linda” (update-in users [1 :age] + 1) [{:name ”Linda" :age 30} {:name ”Tom" :age 21}] (assoc-in users [1 :name] "Sparkles") [{:name ”Linda" :age 30} {:name ”Sparkles" :age 20}])
- 52. [{"name": "Linda", "age":30}, {"name": "Tom", "age": 20}] .[0].name “Linda” .[].age += 1 [{"name": "Linda", "age": 31}, {"name": "Tom", "age": 21}] .[1].name |= "Sparkles” [{"name": "Linda", "age": 30}, {"name": ”Sparkles", "age": 20}]
- 53.
- 54.
- 55.
- 56.
- 57.
- 58.
- 59. Solutions that cut cornersdon’t scale.
- 60.
- 62. class Lens[S,A] class Traversal[S,A] classPrism[S,A] class Iso[S,A] class Fold[S,A] class Getter[S,A] class Setter[S,A] class Optional[S,A]
- 63. import monocle.macros.GenLens case classPos(x: Int, y: Int) object Pos { val x: Lens[Pos,Int] = GenLens[Pos](_.x) val y: Lens[Pos,Int] = GenLens[Pos](_.y) }
- 64. import monocle.macros.Lenses @Lenses case classPos(x: Int, y: Int) @Lenses case class Monster(pos: Pos, embubbled: Boolean) // in build.sbt addCompilerPlugin( "org.scalamacros" %% "paradise" % "2.1.0" cross CrossVersion.full)
- 65.
- 66.
- 67. Goggles principles • Youalready know how to use it • Gets out of the way of experts • Fabulous first-class error messages
- 68. Goggles syntax import goggles._ get"$g.monsters[1].embubbled” set"$g.monsters*.pos.x":= 55555 set"$g.player2?.lives" ~= (_ + 3)
- 69. val g: Game valposL: Lens[Monster, Pos] get"${g}.monsters*.${posL}.x"
- 70.
- 71. ".monsters*." ".x" Hole Name(monsters)Each Hole Name(x) List[String] AST ""
- 72. trait Parse[T, Arg,A] { def apply(state: ParseState[T,Arg]): (Either[GogglesError[T],A], ParseState[T,Arg]) } Interpreter monad
- 73. (List[Arg], List[Info]) (Either[Error,A], List[Arg],List[Info]) Interpreter monad
- 74. ${game} ${posL}Args: Info: AST: Tree: Hole Name(monsters)Each Hole Name(x)
- 75. ${game} ${posL}Args: Info: AST: Hole Tree: ”$game", Unit, Game,Iso, Iso const(game) Name(monsters) Each Hole Name(x)
- 76. Info: AST: Tree: ”$game", Unit, Game,Iso, Iso const(game).composeGetter(Getter(_.monsters)) ".monsters", Game, List[Monster], Getter, Getter ${posL}Args: Name(monsters) Each Hole Name(x)
- 77. Info: AST: Each Hole Name(x) Tree: ”$game", Unit,Game, Iso, Iso const(game).composeGetter(Getter(_.monsters)) .composeTraversal(Each.each) ".monsters", Game, List[Monster], Getter, Getter "*", List[Monster], ??????, Traversal, Fold ${posL}Args: How to learn the type of values?
- 78. Info: AST: Each Hole Name(x) Tree: ”$game", Unit,Game, Iso, Iso const(game).composeGetter(Getter(_.monsters)) .composeTraversal(Each.each) ".monsters", Game, List[Monster], Getter, Getter "*", List[Monster], Monster, Traversal, Fold ${posL}Args: typecheck( q"implicitly[ _root_.monocle.function. Each[List[Monster], _]]") Typechecking will fill it in for us
- 79. Info: AST: Each Hole Name(x) Tree: ”$game", Unit,Game, Iso, Iso const(game).composeGetter(Getter(_.monsters)) .composeTraversal(Each.each) ".monsters", Game, List[Monster], Getter, Getter "*", List[Monster], Monster, Traversal, Fold ${posL}Args: Got it!
- 80. ${posL} Args: Info: AST: Hole Name(x) Tree: ”$game", Unit, Game,Iso, Iso const(game).composeGetter(Getter(_.monsters)) .composeTraversal(Each.each) .composeLens(posL) ".monsters", Game, List[Monster], Getter, Getter "*", List[Monster], Monster, Traversal, Fold ”$posL", Monster, Pos, Lens, Fold
- 81. Info: AST: Name(x) Tree: ”$game", Unit, Game,Iso, Iso const(game).composeGetter(Getter(_.monsters)) .composeTraversal(Each.each) .composeLens(posL) .composeGetter(Getter(_.x)) ".monsters", Game, List[Monster], Getter, Getter "*", List[Monster], Monster, Traversal, Fold ”$posL", Monster, Pos, Lens, Fold ".x", Pos, Int, Getter, Fold
- 82. Info: Error: NameNotFound("BLAH", Int) ”$game",Unit, Game, Iso, Iso ".monsters", Game, List[Monster], Getter, Getter "*", List[Monster], Monster, Traversal, Fold ”$posL", Monster, Pos, Lens, Fold ".x", Pos, Int, Getter, Fold get”$g.monsters*.$posL.x.BLAH"
- 84.
- 85. Optics are hereto stay! • Benefits of immutability • Benefits of mutation • Vast abstractive power
- 86. Optics are hereto stay! • Built-in support is really needed for good usability • Future languages will have built-in optics • Perhaps Goggles can help inform this process! Watch this space!