Welcome to MyLang, a modern programming language designed for flexibility, simplicity, and power. This documentation provides an extensive set of examples and explanations for all key features of MyLang to help you master its capabilities.
MyLang is a dynamically typed, versatile programming language built to be developer-friendly and performant. It supports advanced constructs like pipeline operations, modular imports, flexible functions, and much more.
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Clone the repository:
git clone https://github.com/Sempai-07/mylang.git
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Install dependencies:
npm install
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Link the CLI tool:
npm link
Execute a MyLang file using the CLI:
mylang <your-file.ml>func add(a, b) {
return a + b;
}
coreio.print("Sum:", add(5, 10)); // Sum: 15
func greet(name = "Guest") {
return "Hello, " + name;
}
coreio.print(greet()); // Hello, Guest
coreio.print(greet("Alice")); // Hello, Alice
import "arrays";
func concatStrings() {
return arraya.join(arguments, " ");
}
coreio.print(concatStrings("My", "Lang", "is", "awesome")); // My Lang is awesome
var x = 10;
var y;
coreio.print(x, y); // 10, nil
var counter = 0;
counter += 1;
counter--;
coreio.print(counter); // 0
Using as const, you can declare variables or objects that cannot be reassigned. This ensures immutability for the variable itself but allows modification of its inner elements if it's an array or object.
var constant = 10 as const;
// constant = 5; // Error: Cannot reassign a constant variable
var arr = [] as const; // Declaring an immutable array
arr[0] = 100; // Allowed: Modifying elements of the array
// arr = {}; // Error: Cannot reassign the array
Using as readonly, you can declare variables where neither the variable itself nor its elements can be modified.
var arr1 = [1, 2, 3] as readonly; // Declaring a fully immutable array
// arr1 = {}; // Error: Cannot reassign a readonly variable
// arr1[0] = 0; // Error: Cannot modify elements of a readonly array
This behavior also works for objects:
var obj = { a: 1, b: 2 } as readonly;
// obj.a = 10; // Error: Cannot modify properties of a readonly object
// obj = {}; // Error: Cannot reassign a readonly object
var config = {
appName: "MyLang",
version: "1.0.0"
} as const;
config.appName = "NewName"; // Allowed: Modifying propertie of the object
var data = [10, 20, 30] as readonly;
// data[0] = 100; // Error: Cannot modify elements of a readonly array
var person = {
name: "John",
age: 30,
greet: func() {
return "Hi, I'm " + this.name;
}
};
coreio.print(person.greet()); // Hi, I'm John
var nested = {
outer: {
inner: {
value: 42
}
}
};
coreio.print(nested.outer.inner.value); // 42
var x = 10;
if (x > 5) {
coreio.print("x is greater than 5");
} else {
coreio.print("x is less than or equal to 5");
}
var count = 5;
while (count > 0) {
coreio.print("Countdown:", count);
count--;
}
for (var i = 0; i < 3; i++) {
coreio.print("Iteration:", i);
}
try {
var result = import("nonexistent");
} catch (err) {
coreio.print("Error:", err);
}
try {
coreio.print("Try block");
} finally {
coreio.print("Finally block");
}
MyLang supports importing modules from local files or URLs.
import "./utils.ml";
coreio.print(utils.add(5, 15)); // 20
import("http://example.com/module.ml");
coreio.print(import.base); // Project root directory
coreio.print(import.cache); // Cached modules
coreio.print(import.resolve("module.ml")); // Resolve file path
coreio.print(5 + 3, 5 - 3, 5 * 3, 5 / 3, 5 % 3);
// 8, 2, 15, 1.6666666666666667, 2
coreio.print(5 > 3, 5 == 3, 5 != 3);
// true, false, true
coreio.print(true && false, true || false, !true);
// false, true, false
var car = {
make: "Toyota",
model: "Corolla",
getDetails: func() {
return this.make + " " + this.model;
}
};
coreio.print(car.getDetails()); // Toyota Corolla
var result = 10
|> func(x) { return x * 2 }
|> func(x) { return x + 5 };
coreio.print(result); // 25
var fruits = ["Apple", "Banana", "Orange"];
for (var i = 0; i < fruits.length; i++) {
coreio.print(fruits[i]);
}
coreio.print(Status.getByName("Offline")); // ["Offline", { value: 1, description: "Offline status user" }]
coreio.print(Status.getByName("NonExistent")); // nil
enum Action {
SempaiJS = 7;
Angel = {};
Mz = func main() {};
}
// Action = "Invalid"; // Error: Enums are immutable
coreio.print(Action.SempaiJS); // 7
coreio.print(Action.Angel); // {}
enum Number {
One = 1;
Two; // 2
Three; // 3
}
coreio.print(Number.One, Number.Two, Number.Three); // 1, 2, 3
MyLang provides a powerful match expression for pattern matching, similar to a switch statement in other languages.
func findInt(number) {
match(number) {
case (1): return "One";
case (2): return "Two";
case (3):
case (4):
case (5): return "3, 4 and 5";
default: return "unknown";
}
}
coreio.print(
findInt(1), // One
findInt(2), // Two
findInt(3), // 3, 4 and 5
findInt(6) // unknown
);
func getStatusDescription(status) {
match(status) {
case (Status.Online): return Status.Online.description;
case (Status.Offline): return Status.Offline.description;
default: return "Unknown status";
}
}
coreio.print(
getStatusDescription(Status.Online), // Online status
getStatusDescription(Status.Offline), // Offline status user
getStatusDescription(nil) // Unknown status
);
Enums in MyLang allow you to define a set of named constants and associated values or methods. Enums can contain simple values, objects, or even functions.
enum Status {
Online = { value: 0, description: "Online status" };
Offline = { value: 1, description: "Offline status user" };
func getByName(val) {
var allStatus = objects.entries(this);
for (var i = 0; i < arrays.count(allStatus) - 1; i++) {
if (allStatus[i][0] == val) {
return allStatus[i];
}
}
return nil;
};
}
coreio.print(Status.Online); // { value: 0, description: "Online status" }
coreio.print(Status.Offline); // { value: 1, description: "Offline status user" }
- Run a File
mylang <file.ml>
- Initialize Project
mylang init
- Start REPL
mylang repl
- Version
mylang version
We welcome contributions!