duangsuse::Echo

https://guide.elm-lang.org/ 好像 #Haskell 的语法啊 🤔 case of 还有等号函数定义、layout……

43 viewsduangsuse, 05:08

duangsuse::Echo

import Browser
import Dom.Widgets exposing (div, Text, Button)
import Dom.Events exposing (onClick)

main = Browser.sandbox { init = 0, view = view, update = update }
update state message =
  case msg of
    "inc" -> state + 1
    else -> state
view state =
  div [
    Text ["$state"]
    Button ["inc", "inc"]
  ]

🤔没看几眼就开始默写了，不会

41 viewsduangsuse, 05:16

duangsuse::Echo

import Browser import Dom.Widgets exposing (div, Text, Button) import Dom.Events exposing (onClick) main = Browser.sandbox { init = 0, view = view, update = update } update state message = case msg of "inc" -> state + 1 else -> state view state…

好了，我懂了。

import Browser
import Html exposing (Dom, div, button)
import Html.Events exposing (onClick)

type Msg = Increment | Decrement

main = Browser.sandbox { init = 0, view = view, update = update }

view model =
  div [], [
    ([div [text model] ])
    (button [text "+1"] [onClick Increment]),
    (button [text "-1"] [onClick Decrement])
  ]

update msg model =
  case msg of
    Increment -> model + 1
    Decrement -> model - 1

37 viewsduangsuse, 05:21

duangsuse::Echo

我觉得这一遍应该可以去试水了 🤔

module Main exposing (..)

import Browser
import Html exposing (Html, div, text, button)
import Html.Events exposing (onClick)

type alias Model = Int
type Msg = Increase | Decrease

main = Browser.sandbox { init = 0, view = view, update = update }

view model =
  div []
    [
      div [] [text (String.fromInt model)],
      button [onClick Decrease] [text "-1"],
      button [onClick Increase] [text "+1"]
    ]

update msg model =
  case msg of
    Increase -> model + 1
    Decrease -> model - 1

好了，没想到是这种参数顺序…… 我还以为 f [a 1] [b "?"] 是 "keyword argument" 呢

https://elm-lang.org/examples/buttons

37 viewsduangsuse, edited 06:21

duangsuse::Echo

我觉得这一遍应该可以去试水了 🤔 module Main exposing (..) import Browser import Html exposing (Html, div, text, button) import Html.Events exposing (onClick) type alias Model = Int type Msg = Increase | Decrease main = Browser.sandbox { init = 0, view = view, update =…

其实刚才我觉得 view 定义里，div 的参数列表的 layout 文法很复杂，说明 Elm 的语法实现起来很困难，不能不预取字符就判断是否开启新 layout 深度 🤔
刚才我才发现，只要参数列表不加逗号就是利用 layout 了，不过那还是需要先知道参数个数才能不预取字符。

36 viewsduangsuse, 06:23

duangsuse::Echo

我再来复写下 Random die (1-6) ：

module Main exposing (..)
import Browser
import Html exposing (Html, text, button)
import Html.Events (onClick)
import Random

type alias Model = { dieFace: Int }
type Msg = Roll | NewFace Int

view : Model -> Html Msg
view model =
  div []
    [
      text (String.formInt mode.dieFace),
      button [onClick Roll] [text "Roll"]
    ] 

update: Msg -> Model -> (Model, Cmd)
update msg model =
  case Msg of
    Roll -> (model, Cmd.none)
    (NewFace x) -> (Model { dieFace = x }, Random.rand dieFace (1..6))

subscriptors = Sub.none

35 viewsduangsuse, 06:44

duangsuse::Echo

我再来复写下 Random die (1-6) ： module Main exposing (..) import Browser import Html exposing (Html, text, button) import Html.Events (onClick) import Random type alias Model = { dieFace: Int } type Msg = Roll | NewFace Int view : Model -> Html Msg view model…

……等等，不就是个 Effect 嘛，我又会了

module Main exposing (..)
import Browser
import Html exposing (Html, div, h1, text, button)
import Html.Events exposing (onClick)
import Random

type alias Model { dieFace: Int }
type Msg = Roll | NewFace Int

view model =
  div []
    [
      h1 [] [text (String.fromInt mode.dieFace)],
      button [onClick Roll] [text "Roll"]
    ]
update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
  case msg of
    Roll -> (model, Random.rand (1..6))
    (NewFace x) -> (Model x, Cmd.none)

subscription = Sub.none

35 viewsduangsuse, 06:49

duangsuse::Echo

import Browser
import Html exposing (..)
import Html.Events exposing (onClick)
import Random

type alias Model = { dieFace: Int }
type Msg = Roll | NewFace Int

main = Browser.element { init = init, view = view, update = update, subscriptions = subscriptions }

init : () -> (Model, Cmd Msg)
init _ = (Model 0, Cmd.none)

view : Model -> Html Msg
view model =
  div []
    [
      h1 [] [text (String.fromInt model.dieFace)],
      button [onClick Roll] [text "Roll"]
    ]

update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
  case msg of
    Roll -> (model, Random.generate NewFace (Random.int 1 6))
    (NewFace x) -> (Model x, Cmd.none)

subscriptions : Model -> Sub Msg
subscriptions model = Sub.none

34 viewsduangsuse, edited 06:55

duangsuse::Echo

https://elm-lang.org/examples/cat-gifs
很有意思，所有的视图更新都是在 update 里完成的，Message 则同时负责把数据送至 update 函数
State 都是 immutable 的，这样虽然会造成一些复杂性，但总体来看对程序的简洁性和规范性有很大帮助

31 viewsduangsuse, 07:05

duangsuse::Echo

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30 viewsduangsuse, 07:13

duangsuse::Echo

原来 Haskell 真是可以 industrial 的……

31 viewsduangsuse, 07:13

duangsuse::Echo

extern crate azul;
use azul::{ prelude::*, widgets::{ label::Label, button::Button } };

struct DataModel {
  counter: usize
}
impl Layout for DataModel {
  fn layout(&self, _info: LayoutInfo<DataModel>) -> Dom<DataModel> {
    let label = Label::new(format!("{}", self.state.counter)).dom();
    let btn_inc = Button::with_label("+1").dom().with_callback(Callback(on_inc_clicked));
    Dom::div().with_child(label).with_child(btn_inc);
  }
  fn on_inc_clicked(&self, info: CallbackInfo<DataModel>) -> UpdateScreen {
    info.state.counter += 1
    Redraw
  }
}
fn main() {
  let mut app = App::new(AppOpts::default(), css::native).unwrap();
  let win_main = app.create_window("Counter", WindowOpts::default()).unwrap();
  app.run(win_main).unwrap();
}

32 viewsduangsuse, 07:21

duangsuse::Echo

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33 viewsduangsuse, 07:22

duangsuse::Echo

又写错了一个分号，需要值的地方只有语句
感觉脑子里没有类型一样，难道不知道可以用 Self 吗？ &self 引用了哪里来的 self.state.counter?
with_callback 也忘记加事件了
忘记 impl for 里不该写什么了
App 需要 data model 参数和 AppConfig、create_window 用的名字是 WindowCreateOptions，明白了吗？
（迫真自我批评中）

31 viewsduangsuse, edited 07:22

duangsuse::Echo

extern crate azul;
use azul::{ prelude::*, widgets::{ label::Label, button::Button } };

struct DataModel {
  counter: usize,
}
impl Layout for DataModel {
  fn layout(&self, _info: LayoutInfo<Self>) -> Dom<Self> {
    let label = Label::new(format!("{}", self.counter)).dom();
    let btn_inc = Button::with_label("+1").dom().with_callback(On::ButtonUp, Callback(on_inc_clicked));
    Dom::div().with_child(label).with_child(btn_inc)
  }
}
fn on_inc_clicked(event: CallbackInfo<DataModel>) -> UpdateScreen {
  event.state.counter += 1
  Redraw
}
fn main() {
  let mut app = App::new(DataModel { counter: 0 }, AppConfig::default()).unwrap();
  let win_main = app.create_window(WindowCreateOptions::default(), css::native()).unwrap();
  app.run(win_main).unwrap();
}

30 viewsduangsuse, 07:31

duangsuse::Echo

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31 viewsduangsuse, 07:31

duangsuse::Echo

还是少写了个 data，event.state.data.counter，唉，我应该清楚 state 不止 user data 的，就是不动脑子分析。
with_callback 也是临时突然忘了，想起有 with_ 再试试 with_event, with_handler 后才推出的
最后的 fn main() 倒是写对了

31 viewsduangsuse, edited 07:32

duangsuse::Echo

Forwarded from Solidot

LLVM 10.0.0 发布

LLVM 编译器套装项目释出了 10.0.0 版本。LLVM 项目目前的发布计划为每半年发布一个大版本。10.0.0 版本的主要变化包括：Clang 支持 C++ Concepts；Clang 默认不再运行在一个独立进程上；支持 Windows 10 内置的安全特性 Control Flow Guard (CFG)；支持更多处理器核心和特性，等等。更多可浏览 LLVM、Clang、Extra Clang Tools、lld 和 libc++ 的发布公告。Media

https://www.solidot.org/story?sid=63921

5 viewsduangsuse, 07:34

Show comments

duangsuse::Echo

喜欢本频道的内容吗？

看起来不喜欢的人多一些，也罢，反正我不常弄些能吸引人的东西 😂

38 viewsduangsuse, edited 07:36

duangsuse::Echo

extern crate azul; use azul::{ prelude::*, widgets::{ label::Label, button::Button } }; struct DataModel { counter: usize } impl Layout for DataModel { fn layout(&self, _info: LayoutInfo<DataModel>) -> Dom<DataModel> { let label = Label::new(format!("{}"…

不知道会不会有人看我在线默写会觉得很尴尬，反正这种行为只是在我看到比较有意思的项目时会去默写一些 example
一般情况下还是不会出现的，我也会用这种方法帮助自己理解一门语言/一种设计命名方式的直觉

频道的空间相对有限，所以我不会让这类消息过于频繁的出现。

40 viewsduangsuse, 07:40

duangsuse::Echo

#zhihuPost 如何看待 2020 年 3 月 23 日哔哩哔哩将稿件的「av 号」变更为「BV 号」？ - duangsuse的回答 - 知乎
https://www.zhihu.com/question/381784377/answer/1103862380