判别联合&让约束力?
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19-09-2019 - |
题
为什么let绑定不是在歧视工会允许的?我认为它有一个默认的构造函数
让绑定正在执行?做在次级音符如何我可以重写AI_Choose
任何建议,将不胜感激。我想保持加权优先与AI的元组。我的想法是让AI_Weighted_Priority
继承AI_Priority
并重写选择。我不想处理荏苒不同长度的列表(坏习惯海事组织。)
open AI
type Condition =
| Closest of float
| Min
| Max
| Average
member this.Select (aiListWeight : list<AI * float>) =
match this with
| Closest(x) ->
aiListWeight
|> List.minBy (fun (ai, priority) -> abs(x - priority))
| Min -> aiListWeight |> List.minBy snd
| Max -> aiListWeight |> List.maxBy snd
| Average ->
let average = aiListWeight |> List.averageBy snd
aiListWeight
|> List.minBy (fun (ai, priority) -> abs(average - priority))
type AI_Choose =
| AI_Priority of list<AI> * Condition
| AI_Weighted_Priority of list<AI * float> * Condition
// I'm sad that I can't do this
let mutable chosen = Option<AI>.None
member this.Choose() =
match this with
| AI_Priority(aiList, condition) ->
aiList
|> List.map (fun ai -> ai, ai.Priority())
|> condition.Select
|> fst
| AI_Weighted_Priority(aiList, condition) ->
aiList
|> List.map (fun (ai, weight) -> ai, weight * ai.Priority())
|> condition.Select
|> fst
member this.Chosen
with get() =
if Option.isNone chosen then
chosen <- Some(this.Choose())
chosen.Value
and set(x) =
if Option.isSome chosen then
chosen.Value.Stop()
chosen <- Some(x)
x.Start()
interface AI with
member this.Start() =
this.Chosen.Start()
member this.Stop() =
this.Chosen.Stop()
member this.Reset() =
this.Chosen <- this.Choose()
member this.Priority() =
this.Chosen.Priority()
member this.Update(gameTime) =
this.Chosen.Update(gameTime)
解决方案
这将使意义,让“放”结合的内部识别联合。我想,为什么这是不可能的原因是识别联合仍然是基于OCaml的设计,同时对象来自.NET世界。 F#是试图这两尽可能整合,但它很可能走得更远。
总之,在我看来,你正在使用的判别工会只实现AI_Choose
类型内部的一些行为。在这种情况下,你可以单独声明可识别联合并用它来实现对象类型。
我相信你可以写这样的:
type AiChooseOptions =
| AI_Priority of list<AI> * Condition
| AI_Weighted_Priority of list<AI * float> * Condition
type AiChoose(aiOptions) =
let mutable chosen = Option<AI>.None
member this.Choose() =
match aiOptions with
| AI_Priority(aiList, condition) -> (...)
| AI_Weighted_Priority(aiList, condition) -> (...)
member this.Chosen (...)
interface AI with (...)
类层次结构和可识别联合之间的主要区别是,当涉及到可扩展性。类更容易增加新的类型,同时识别联合更容易添加与该类型的工作(在你的情况AiChooseOptions)的新功能,所以这可能是设计应用程序时,首先要考虑的事情。
其他提示
有关任何有兴趣我最终导出从一个抽象基类AI_Priority
和AI_Weighted_Priority
。
[<AbstractClass>]
type AI_Choose() =
let mutable chosen = Option<AI>.None
abstract member Choose : unit -> AI
member this.Chosen
with get() =
if Option.isNone chosen then
chosen <- Some(this.Choose())
chosen.Value
and set(x) =
if Option.isSome chosen then
chosen.Value.Stop()
chosen <- Some(x)
x.Start()
interface AI with
member this.Start() =
this.Chosen.Start()
member this.Stop() =
this.Chosen.Stop()
member this.Reset() =
this.Chosen <- this.Choose()
member this.Priority() =
this.Chosen.Priority()
member this.Update(gameTime) =
this.Chosen.Update(gameTime)
type AI_Priority(aiList : list<AI>, condition : Condition) =
inherit AI_Choose()
override this.Choose() =
aiList
|> List.map (fun ai -> ai, ai.Priority())
|> condition.Select
|> fst
type AI_Weighted_Priority(aiList : list<AI * float>, condition : Condition) =
inherit AI_Choose()
override this.Choose() =
aiList
|> List.map (fun (ai, weight) -> ai, weight * ai.Priority())
|> condition.Select
|> fst
重温此代码我最终采取托马斯的建议这原来很多清洁器。
type AiChooseOptions =
| Priority of List<AI * Priority>
| WeightedPriority of List<AI * Priority * float>
member this.Choose(condition : Condition) =
match this with
| Priority(list) ->
list
|> List.map (fun (ai, priority) -> ai, priority.Priority())
|> condition.Select
| WeightedPriority(list) ->
list
|> List.map (fun (ai, p, weight) -> ai, p.Priority() * weight)
|> condition.Select
type AiChoose(condition, list : AiChooseOptions ) =
let mutable chosen = Unchecked.defaultof<AI>, 0.0
interface AI with
member this.Update(gameTime) =
(fst chosen).Update(gameTime)
interface Priority with
member this.Priority() =
chosen <- list.Choose(condition)
(snd chosen)
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