在Elm中立即启动计时器

我希望下面的代码在打开和关闭计时器时异步增加计数。但它总是同步工作（增量为2）

如何使其异步

编辑：可能是由于我的英语能力不足，这个问题似乎经常被误解。我希望实现的行为与我的答案完全相同。关键是，两个计时器应该通过切换分别增加计数

---

解决这个问题的方法如下，但这当然是不可取的。我想尽可能多地使用其他解决方案。请为我提供可靠的方法

import Html exposing (program, div, button, text)
import Html.Events exposing (onClick)
import Time exposing (every, second)

main = program
  { init = ({cnt = 0, on = True}, Cmd.none)
  , view = view
  , update = update
  , subscriptions = subscriptions
  }

subscriptions model = Sub.batch
  [ every (second + 0.0000000001) (always Increment)
  , if model.on then every second (always Increment) else Sub.none
  ]

view model = div []
  [ button [ onClick Toggle ] [ text "-" ]
  , div [] [ text (toString model) ]
  , button [ onClick Increment ] [ text "+" ]
  ]

type Msg = Increment | Toggle

update msg model =
  case msg of
    Increment ->
      ({model | cnt = model.cnt + 1}, Cmd.none)
    Toggle ->
      ({model | on = not model.on}, Cmd.none)

---

这是一个版本，当

打开时，每秒递增1，并且始终允许手动递增1

import Html exposing (program, div, button, text)
import Html.Events exposing (onClick)
import Time exposing (every, second)

main = program
  { init = ({cnt = 0, on = True}, Cmd.none)
  , view = view
  , update = update
  , subscriptions = subscriptions
  }

subscriptions model = Sub.batch
  [ every second (always Tick)
  ]

view model = div []
  [ button [ onClick Toggle ] [ text "Toggle" ]
  , div [] [ text (toString model) ]
  , button [ onClick Increment ] [ text "+" ]
  ]

type Msg = Tick | Toggle | Increment

update msg model =
  case msg of
    Increment ->
      ({model | cnt = model.cnt + 1}, Cmd.none)

    Tick ->
      case model.on of
        True ->
          ({model | cnt = model.cnt + 1}, Cmd.none)
        False ->
          (model, Cmd.none)

    Toggle ->
      ({model | on = not model.on}, Cmd.none)

我对我的问题作了补充澄清。有一个答案与您的答案类似。为了清楚起见：您希望显示的输出为：1、2、3、4，而不管model.on是否为真。model.on只应根据切换实际发生的时间影响显示更改的速度。但问题是当model.on为真时，它显示1、3、5。而不是1，2，3，4，5在一个不同的速度比以前。如果我正确理解了你的问题，请告诉我。@Jigar是的。这就是我的意思。
import Html exposing (program, div, button, text)
import Html.Events exposing (onClick)
import Time exposing (every, second)

main = program
  { init = ({cnt = 0, on = True}, Cmd.none)
  , view = view
  , update = update
  , subscriptions = subscriptions
  }

subscriptions model = Sub.batch
  [ every second (always Tick)
  ]

view model = div []
  [ button [ onClick Toggle ] [ text "Toggle" ]
  , div [] [ text (toString model) ]
  , button [ onClick Increment ] [ text "+" ]
  ]

type Msg = Tick | Toggle | Increment

update msg model =
  case msg of
    Increment ->
      ({model | cnt = model.cnt + 1}, Cmd.none)

    Tick ->
      case model.on of
        True ->
          ({model | cnt = model.cnt + 1}, Cmd.none)
        False ->
          (model, Cmd.none)

    Toggle ->
      ({model | on = not model.on}, Cmd.none)