Introduction

I’ve recorded an MP4 demo to showcase the results. In the video, you’ll see the Markdown content being displayed
character by character, with dynamic rendering and automatic scrolling.

Demo MP4

In this article, I’ll walk you through a simple yet powerful demo of implementing stream output in JavaScript. This
demo
mimics the behavior of ChatGPT-like applications, where responses are displayed in a streaming fashion, and the
content
is dynamically rendered as Markdown. The best part? It’s incredibly simple to implement, and I’ll provide the full
source code and an MP4 demo to showcase the results.

ES6 引入了一种新的原始数据类型 Symbol，表示独一无二的值。
Symbol 值通过 Symbol 函数生成，也就是说，对象的属性名现在可以有两种类型：一种是字符串，另一种就是 Symbol 类型。只要属性名属于 Symbol 类型，就是独一无二的，可以保证不会与其他属性名冲突。

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let s = Symbol()
typeof s //symbol

Symbol 函数可以接受一个字符串作为参数，表示对 Symbol 实例的描述，主要是为了在 console 显示。

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let s = Symbol("str")
s.toString() //'Symbol(str)'

如果 Symbol 的参数是一个对象，就会调用该对象的 toString 方法，再生成 Symbol 值

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const obj = {
  toString() {
    return "test"
  },
}
const s = Symbol(obj)
s.toString() //'Symbol(test)'

TG（目前）最大的需求–宣传

前几天在 TG，有个人问我如何实现一个 TG 批量拉人入某个 group。找了找资料发现真的可以实现。

测试了似乎单次最多只能邀请 30 人进组，并且一个人邀请太多人会被禁止单项邀请。
TG 还能不进群，直接拉进去，直接获取某个群组的所有 member，太 BUG 了

有类似想法的可以联系我，与我交流。

Function Composition

In computer science, function composition is an act or mechanism to combine simple functions to build more complicated ones. Like the usual composition of functions in mathematics, the result of each function is passed as the argument of the next, and the result of the last one is the result of the whole. -- Wikipedia

Example:

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var compose = (f, g) => (x) => f(g(x))
var head = (x) => x[0]
var reverse = reduce((a, x) => [x].concat(a), [])

var last = compose(head, reverse)
last(["first", "second", "last"]) // 'last'

In the definition of compose, g will be executed before f, thus creating a right-to-left data stream. This is much more readable than nesting a bunch of function calls.

Associativity

Like many other functional programming concepts, associativity is derived from math.It is an expression in which the order of evaluation does not affect the end result provided the sequence of the operands does not get changed. -- JOSEPH REX

Example:

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2 + (3 + 4) === 2 + 3 + 4 // true
2 * (3 * 4) === 2 * 3 * 4 // true

Because of the grouping of calls to compose is not important, so the result is the same. This also gives us the ability to write a variadic compose.
Like this:

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var last = compose(head, reverse)
last(["first", "second", "last"]) // 'last'

var upperLast = compose(head, reverse, toUppercase)
upperLast(["first", "second", "last"]) // 'LAST'

var mediaUrl = _.compose(_.prop("m"), _.prop("media"))
// var images = _.compose(_.map(img), _.map(mediaUrl), _.prop('items'));
// use the associativity
var images = _.compose(_.map(_.compose(img, mediaUrl)), _.prop("items"))

There is no standard answer on how to composition, just make it more reusable.

What is currying

Currying is the technique of translating the evaluation of a function that takes multiple arguments into evaluating a sequence of functions, each with a single argument. -- Wikipedia
It mean this:

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let add = (x) => (y) => x + y
let addOne = add(1)
let addTwo = add(2)
addOne(11) // 12
addTwo(11) // 13

In order to define functions more easily, we need the loadsh, it will help us to currying the function.

make some using thing

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var _ = require("loadsh").curry

var match = _((regex, str) => str.match(regex))
var replace = _((regex, replacement, str) => str.replace(regex, replacement))
var filter = _((f, array) => array.filter(f))
match(/\s+/g, "test Message") // [' ']
match(/\s+/g)("test Message") // [' ']

var hasSpace = match(/\s+/g)
hasSpace("testMessage") // null
filter(hasSpace, ["testMessage1", "test Message2", "test Message 3"]) // ['test Message2', 'test Message 3']
var noA = replace(/[Aa]+/g, "*")
noA("aaaabbbAAAc") // '*bbb*c'