cRAzY eSnEXt (*all* proposals mixed in)

2018.js

#! Aaaaaaaaaaa this is JS!!!
// https://github.com/tc39/proposal-hashbang
// This file is mixing all new syntaxes in the proposal in one file without considering syntax conflict or correct runtime semantics
// Enjoy!!! 
// Created at Nov 23, 2018

for await(const x of (new A // https://github.com/tc39/proposal-pipeline-operator
|> do { // https://github.com/tc39/proposal-do-expressions
    case(?) { // https://github.com/tc39/proposal-pattern-matching
        when {val}: class {
            #[?]: ?; // https://github.com/tc39/proposal-private-fields
            fn(...n) {
                // https://github.com/tc39/proposal-nullish-coalescing
                // https://github.com/tc39/proposal-slice-notation
                return this.#[?] ??= n[2:3]
            }
        }
        when _: ?
    }
}
|> ::?.fn // https://github.com/tc39/proposal-bind-operator
|> ?.map do(x) { x -> x + 1}
// https://github.com/tc39/proposal-record-tuple
// https://github.com/tc39/proposal-numeric-separator
// https://github.com/tc39/proposal-extended-numeric-literals
|> (? ?? ? ?? {# a: 1_2_3 #} ?? {| b:2_px |})
|> (async _ =>* { return ? })()) { // https://github.com/tc39/proposal-generator-arrow-functions
}

2019.js

#! Aaaaaaaaaaa this is JS!!!
// https://github.com/tc39/proposal-hashbang
// This file is mixing all new syntaxes in the proposal in one file without considering syntax conflict or correct runtime semantics
// Enjoy!!! 
// Created at Jun 17, 2019

mixin W {} // mixin proposal, I can't find a link for it
let val = do { // https://github.com/tc39/proposal-do-expressions
    // https://github.com/tc39/proposal-generator-arrow-functions
    // https://github.com/tc39/proposal-logical-assignment
    // https://github.com/tc39/proposal-throw-expressions
    ((f ||= throw new TypeError('Aaaaaahhhhh')) =>* {
        "hide implementation" // https://github.com/tc39/proposal-function-implementation-hiding
        protocol Ahhhhhhh { // https://github.com/tc39/proposal-first-class-protocols
            tag;
            toString() {
                return `[object ${this[Ahhhhhhh.tag]}]`[2:6]; // https://github.com/tc39/proposal-slice-notation
            }
        }
        Protocol.implement(Promise, function.sent); // https://github.com/tc39/proposal-function.sent
        case ( // https://github.com/tc39/proposal-pattern-matching
            yield
            |> await // https://github.com/tc39/proposal-pipeline-operator
            |> (yield #)
            |> fn(a ??= ? ?? ? ?? ? ?? ? ?? ? ?? ? ?? ? ?? ? ?? ?, 2333)
            |> a(1) { } // I don't recall what this proposal is
        ) { // https://github.com/tc39/proposal-private-fields
            // https://github.com/tc39/proposal-class-static-block
            when a -> a |> ? ?? ? ?? class { #[?]: ?, static { do {? ?? ?}} }
        }
    })?.() ?.next( // https://github.com/tc39/proposal-nullish-coalescing
        class Comment extends Model |> Editable |> Sharable |> Promisable with M {
            static {
                using(class.f()) {}
            }
            constructor() { // https://github.com/littledan/proposal-new-initialize
                new.initialize()
            }
        } // https://github.com/tc39/proposal-extended-numeric-literals
    ).next(233@px)
}
// https://github.com/tc39/proposal-decorators
decorator @px {
    @numericTemplate(({ number }) => CSS.px(number))
}

2020.js

#! Aaaaaaaaaaa this is JS!!!
// https://github.com/tc39/proposal-hashbang
// This file is mixing all new syntaxes in the proposal in one file 
// without considering syntax conflict or correct runtime semantics
// Enjoy!!! 
// Created at Nov 21, 2020 by @jackworks_asref

// https://github.com/tc39/proposal-import-assertions#follow-up-proposal-evaluator-attributes
import data from "./data.json" assert { type: "json" } with { as: "record" }; 

import { onTransform, unwrap, log, onMounted, sensitive, dispatch, smartElement, CSS } from './utils.js';

// https://github.com/tc39/ecma262/pull/2154 and https://github.com/hax/proposal-extensions
import ::{ "😂" as send } from "async-call-rpc"; 

// https://github.com/tc39/proposal-asset-references
asset report from "report"; 

// https://github.com/tc39/proposal-operator-overloading
with operators from Decimal; 

// https://github.com/tc39/proposal-extended-numeric-literals
with suffix px = CSS.px 

// https://github.com/tc39/proposal-first-class-protocols
protocol RPC { 
    address;
    // https://github.com/tc39/proposal-wavy-dot
    send(method, ...args) { return this.address::send()~.[method](...args) } 
} 

// https://github.com/tc39/proposal-decorators/blob/master/EXTENSIONS.md#annotation-syntax
@{ author: "Jack Works" } 
// https://github.com/justinfagnani/proposal-mixins
class MyHandler extends HTMLElement with smartElement { 
    // async init proposal 
    async constructor() { 
        super(); 
        // https://github.com/tc39/proposal-await.ops 
        await.race [
            import(report), 
            // https://github.com/tc39/proposal-js-module-blocks
            import(module { export default await import('./fallback.js') })
        ] 
    } 

    // https://github.com/tc39/proposal-private-declarations
    outer static #brand = 'my handler' 

    // https://github.com/tc39/proposal-class-static-block
    static { 
        https://github.com/tc39/proposal-standardized-debug
        debugger.log(['Defined as ', this, this.#brand]) 
    }  

    // https://github.com/tc39/proposal-slice-notation
    #data = data[0:100]; 

    onNewChild(child) { 
        // https://github.com/tc39/proposal-private-fields-in-in
        !(try child.#data) 
            // https://github.com/tc39/proposal-throw-expressions
            && throw new TypeError('Illegal') 
    } 

    // https://github.com/tc39/proposal-generator-arrow-functions
    [Symbol.asyncIterator]: async () =>* { 
        "hide source" // https://github.com/tc39/proposal-function-implementation-hiding

        // https://github.com/tc39/proposal-function.sent
        while (function.sent) 
            for (const datum of this.#data) {
                // https://github.com/tc39/proposal-explicit-resource-management
                try using(const f = function.sent) { 
                    yield do { // https://github.com/tc39/proposal-do-expressions
                        // https://github.com/tc39/proposal-pipeline-operator 
                        // and https://github.com/tc39/proposal-partial-application 
                        // and https://github.com/tc39/proposal-Declarations-in-Conditionals
                        if (const val = datum |> sensitive |> f(this, ?) |> await.all |> sensitive) { 
                            // https://github.com/tc39/proposal-pattern-matching
                            val = case (val) { 
                                // https://github.com/tc39/proposal-record-tuple
                                when #{ type: 'throw', error: e } -> 
                                    throw new Error(e), 
                                when #{ type: 'batch', list: arr } -> 
                                    await.all arr.map(x => import(x)),
                                // https://github.com/tc39/proposal-deep-path-properties-for-record
                                when #{ type: 'normal', ...rest } -> 
                                    #{ ...val, meta.received: Date.now() } 
                            }
                            runTimes++; 
                            // https://github.com/keithamus/proposal-object-freeze-seal-syntax
                            val |> dispatch(this, 'transform', {| details: val |}); 
                        } 
                    } 
                } 
            } 
    } 

    // https://github.com/tc39/proposal-decorators#option-b-init-method-decorators
    @init: onTransform transformHandler = 
        () => this.style.fontSize ||= runTimes > 10 ? 24px : 12px

    // https://github.com/tc39/proposal-decorators/blob/master/EXTENSIONS.md#block-decorators
    @onMounted {  
        // https://github.com/samuelgoto/proposal-block-params 
        // and https://github.com/tc39/proposal-decorators/blob/master/EXTENSIONS.md#parameter-decorators-and-annotations
        this.addEventListener('transform') do (@unwrap event) { 
            // https://github.com/tc39/proposal-class-access-expressions
            console.log(event, class.#brand) 
        } 
    } 
    
    static [RPC.address] = 'http://localhost:8080/';
}; 

Protocol.implement(MyHandler, RPC);

// https://github.com/tc39/proposal-decorators/blob/master/EXTENSIONS.md#let-decorators
let @(log(x => `@@iterator on ${MyHandler.#brand} ran for ${x} times`)) 
    // https://github.com/tc39/proposal-decimal
    runTimes = 0m; 

try { 
    // nested imports
    // https://github.com/benjamn/reify/blob/master/PROPOSAL.md 
    import dev from "enhance-devtools"; window.devtoolsFormatters = #[...window?.devtoolsFormatters, dev]; 
} catch {}