Mew Programming Language for VS Code 🐱

A Visual Studio Code extension that adds language support for Mew, a cat-themed programming language.

Features 🐾

• Syntax highlighting for .mew files
• Custom file icon for Mew files
• Language configuration (brackets, comments)

Mew Language Syntax

Mew is a cat-themed programming language with the following elements:

Keywords

• Variables: catv, catst, catlt
• Function Declaration: cat
• Control Flow: meow?, meowse?, hiss, mewhile, mewdo, catwalk, meownext, purr
• Types: fur, claw, clawt
• Other: return, default
• Operators: =>, in, of

Constants

• Boolean: true, false
• Special Values: null, undefined, NaN, Infinity, -Infinity

Comments

Single-line comments use double slashes: // This is a comment

Example Code

// Comprehensive Mew Language Features
purr("Mew Language Feature Examples");

// ===== SECTION 1: VARIABLES AND DATA TYPES =====
purr("\n1. Variables and Data Types:");

// Variable declarations with different types
catst PI = 3.14159;  // Constant (can't be reassigned)
catlt name = "Whiskers";  // Let variable
catv counter = 0;  // Var variable

// Different data types
catlt numberValue = 42;  // Number
catlt stringValue = "Hello Mew!";  // String
catlt boolValue = true;  // Boolean
catlt nullValue = null;  // Null
catlt undefinedValue = undefined;  // Undefined

// Display variable values
purr("PI value (constant): " + PI);
purr("Name (let): " + name);
purr("Counter (var): " + counter);

// Display data types
purr("Number value: " + numberValue);
purr("String value: " + stringValue); 
purr("Boolean value: " + boolValue);
purr("Null value: " + nullValue);
purr("Undefined value: " + undefinedValue);

// ===== SECTION 2: OPERATORS =====
purr("\n2. Operators:");

// Arithmetic operators
purr("Addition: " + (5 + 3));
purr("Subtraction: " + (10 - 4));
purr("Multiplication: " + (6 * 7));
purr("Division: " + (20 / 4));
purr("Modulus: " + (17 % 5));

// Increment/decrement
catlt x = 10;
purr("Initial x: " + x);
purr("Prefix increment (++x): " + (++x));  // Now x is 11
purr("Postfix increment (x++): " + (x++));  // Returns 11, then x becomes 12
purr("After operations, x is: " + x);  // Shows 12

// Comparison operators
purr("Equality (5 == 5): " + (5 == 5));
purr("Inequality (5 != 3): " + (5 != 3));
purr("Greater than (5 > 3): " + (5 > 3));
purr("Less than or equal (5 <= 5): " + (5 <= 5));

// Logical operators
purr("Logical AND (true && true): " + (true && true));
purr("Logical OR (false || true): " + (false || true));
purr("Logical NOT (!false): " + (!false));

// ===== SECTION 3: CONTROL FLOW =====
purr("\n3. Control Flow:");

// If statement
catlt temperature = 28;
purr("Temperature is: " + temperature);

meow? (temperature > 30) {
    purr("It's hot outside!");
} meowse? (temperature > 20) {
    purr("It's warm outside.");
} hiss {
    purr("It's cool outside.");
}

// Simplified if statement
catlt dayType = "";
catlt day = "Saturday";

meow? (day == "Saturday" || day == "Sunday") {
    dayType = "weekend";
} hiss {
    dayType = "weekday";
}
purr("Today is a " + dayType);

// ===== SECTION 4: LOOPS =====
purr("\n4. Loops:");

// For loop
purr("For loop counting from 1 to 5:");
fur (catlt i = 1; i <= 5; i++) {
    purr("Count: " + i);
}

// While loop
purr("\nWhile loop counting down from 5:");
catlt countdown = 5;
mewhile (countdown > 0) {
    purr("Countdown: " + countdown);
    countdown--;
}

// ===== SECTION 5: ARRAYS =====
purr("\n5. Arrays:");

// Array declaration and initialization
catlt fruits = ["apple", "banana", "cherry", "date"];
purr("Fruits array: " + fruits);
purr("Array length: " + fruits.length);

// Accessing array elements
purr("First fruit: " + fruits[0]);
purr("Last fruit: " + fruits[3]);  // Using direct index instead of length-1

// Array iteration
purr("\nIterating through array using for loop:");
fur (catlt i = 0; i < fruits.length; i++) {
    purr("Fruit " + (i + 1) + ": " + fruits[i]);
}

// ===== SECTION 6: FUNCTIONS =====
purr("\n6. Functions:");

// Basic function
cat greet(name) {
    return "Hello, " + name + "!";
}
purr(greet("Mew"));

// Function with multiple parameters
cat add(a, b) {
    return a + b;
}
purr("2 + 3 = " + add(2, 3));

// Function with calculations
cat power(base, exponent) {
    catlt result = 1;
    fur (catlt i = 0; i < exponent; i++) {
        result = result * base;
    }
    return result;
}
purr("2^3 = " + power(2, 3));

// Recursive function
cat factorial(n) {
    meow? (n <= 1) {
        return 1;
    } hiss {
        return n * factorial(n - 1);
    }
}
purr("Factorial of 5: " + factorial(5));

// Function expression (anonymous function)
catlt multiply = cat(a, b) {
    return a * b;
};
purr("4 * 5 = " + multiply(4, 5));

// ===== SECTION 7: SCOPE =====
purr("\n7. Scope:");

// Global and local scope
catv globalVar = "I'm global";

cat testScope() {
    catlt localVar = "I'm local";
    purr("Inside function - globalVar: " + globalVar);
    purr("Inside function - localVar: " + localVar);
}

testScope();
purr("Outside function - globalVar: " + globalVar);

purr("\nAll language features demonstrated successfully!"); 

Installation

1. Open VS Code
2. Go to Extensions (Ctrl+Shift+X)
3. Search for "Mew Language"
4. Click Install

Requirements

• VS Code 1.100.0 or higher

Development

This extension is in early development (version 0.0.1). Contributions are welcome!

License

Mew Language is licensed under the MIT License. See the LICENSE file for details.

Icon based on Microsoft Fluent Emoji. Licensed under MIT. https://github.com/microsoft/fluentui-emoji

Made with 💖 by MewTheDev