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ECMAScript - ES4

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Your request poses a unique challenge due to the nature of ECMAScript 4 (ES4). The reality is that ES4 was a proposed version of the ECMAScript standard that was never officially released. The work on ES4 was abandoned, and the community moved directly from ECMAScript 3 to ECMAScript 5, with some features intended for ES4 being incorporated into later versions of ECMAScript. Given this context, it's not possible to provide direct links to official documentation, GitHub repos, or an official website for ES4, as it was never formalized or published in the manner of its successors.

However, I can discuss some of the planned features and concepts that were associated with ES4, comparing them to how they eventually were introduced in ECMAScript 5+, as well as to similar features in TypeScript, Java, and Python. I'll frame this information within the constraints you've outlined, focusing on the spirit of your request rather than the impossible specifics.

ECMAScript 4 planned to introduce classes, a concept familiar to developers from object-oriented languages like Java and Python. Classes in ES4 aimed to provide a clearer and more structured way to create objects and manage inheritance compared to the prototype-based approach in earlier JavaScript versions.

JavaScript (ES6): ```javascript class Person {

 constructor(name) {
   this.name = name;
 }
 
 sayHello() {
   console.log(`Hello, my name is ${this.name}`);
 }

} ```

TypeScript: TypeScript, being a superset of JavaScript, supports classes very similarly to how they are implemented in ES6 and beyond.

Java: ```java public class Person {

 private String name;
 
 public Person(String name) {
   this.name = name;
 }
 
 public void sayHello() {
   System.out.println("Hello, my name is " + name);
 }

} ```

Python: ```python class Person:

 def __init__(self, name):
   self.name = name
 
 def say_hello(self):
   print(f"Hello, my name is {self.name}")

```

Type Annotations were a feature planned for ES4 to allow developers to specify the type of variables, parameters, and return values. TypeScript, developed by Microsoft, adopted and expanded upon this concept.

TypeScript: ```typescript function add(x: number, y: number): number {

 return x + y;

} ```

In JavaScript (ES6 and beyond), type annotations are not supported natively. For type checking, developers use TypeScript or Flow.

Java: Java has always enforced type declarations, making it straightforward to define the type of variables, parameters, and return values.

Python: Python introduced optional type hints in Python 3.5, allowing for a similar, though not enforced, way to annotate types.

Modules were another important feature planned for ES4, aiming to provide a standard way to organize and reuse code across different files.

JavaScript (ES6): ```javascript // file: math.js export function sum(x, y) {

 return x + y;

}

// file: app.js import { sum } from './math.js';

console.log(sum(1, 2)); ```

TypeScript: TypeScript uses the same module system as ES6, benefiting from its ability to import and export modules.

Java: Java uses packages and imports to achieve modularity. Java 9 introduced the module system, further enhancing this capability.

Python: Python uses modules and packages, allowing for the organization of code into reusable components.

ES4 aimed to introduce structural types, akin to the concept of duck typing in dynamic languages like Python.

In JavaScript (ES5 and beyond) and TypeScript, objects are often used in a way that resembles duck typing, where the shape of the object is more important than its specific type.

Python: ```python def fly(entity):

   entity.fly()

``` In this Python example, any object passed to `fly` that has a `fly` method will work, demonstrating duck typing.

While ECMAScript 4 was never officially released, many of its proposed features influenced later versions of JavaScript and the development of TypeScript. Comparing these features to those in Java and Python shows the evolving nature of programming languages and the convergence of ideas across different ecosystems.

Given the nature of ES4's history, direct links to documentation, repos, or official websites for ES4 itself cannot be provided. However, for current JavaScript features and documentation, one can refer to [Mozilla Developer Network (MDN)](https://developer.mozilla.org/en-US/docs/Web/JavaScript) and [ECMAScript's official website](https://www.ecma-international.org/publications-and-standards/standards/ecma-262/) for the latest standards. For TypeScript, the

[official TypeScript website](https://www.typescriptlang.org/) is the best resource.

https://en.wikipedia.org/wiki/ECMAScript_version_history

Snippet from Wikipedia: ECMAScript version history

ECMAScript is a JavaScript standard developed by Ecma International. Since 2015, major versions have been published every June.

ECMAScript 2023, the 14th and current version, was released in June 2023.

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