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Nishal K edited this page Sep 29, 2025 · 1 revision

Examples

This page contains practical examples demonstrating Veyra's features and capabilities. Each example includes the code and explanation of what it does.

Table of Contents

Basic Examples

Hello World

println("Hello, World!");

The classic first program that prints a greeting to the console.

Variables and Types

// Numbers
let age = 25;
let pi = 3.14159;

// Strings
let name = "Alice";
let greeting = "Hello, " + name + "!";

// Booleans
let is_active = true;
let is_admin = false;

// Arrays
let numbers = [1, 2, 3, 4, 5];
let names = ["Alice", "Bob", "Charlie"];

// Dictionaries
let person = {
    "name": "Alice",
    "age": 30,
    "city": "New York"
};

Basic Math

let a = 10;
let b = 3;

println("Addition: " + to_string(a + b));        // 13
println("Subtraction: " + to_string(a - b));     // 7
println("Multiplication: " + to_string(a * b));  // 30
println("Division: " + to_string(a / b));        // 3.333...
println("Modulus: " + to_string(a % b));        // 1
println("Power: " + to_string(pow(a, b)));       // 1000

Control Flow

If-Else Statements

let age = 18;

if age >= 18 {
    println("You are an adult");
} else {
    println("You are a minor");
}

// Nested conditions
let score = 85;
if score >= 90 {
    println("Grade: A");
} else if score >= 80 {
    println("Grade: B");
} else if score >= 70 {
    println("Grade: C");
} else {
    println("Grade: F");
}

Loops

// For loop with range
for i in 0..5 {
    println("Count: " + to_string(i));
}

// For loop with array
let fruits = ["apple", "banana", "orange"];
for fruit in fruits {
    println("I like " + fruit);
}

// While loop
let counter = 0;
while counter < 5 {
    println("Counter: " + to_string(counter));
    counter = counter + 1;
}

Functions

Simple Function

fn greet(name) {
    return "Hello, " + name + "!";
}

let message = greet("Alice");
println(message);  // "Hello, Alice!"

Function with Multiple Parameters

fn calculate_area(width, height) {
    return width * height;
}

let area = calculate_area(10, 5);
println("Area: " + to_string(area));  // "Area: 50"

Recursive Function

fn factorial(n) {
    if n <= 1 {
        return 1;
    } else {
        return n * factorial(n - 1);
    }
}

println("5! = " + to_string(factorial(5)));  // "5! = 120"

Classes and Objects

Simple Class

class Person {
    fn init(name, age) {
        this.name = name;
        this.age = age;
    }

    fn greet() {
        return "Hello, I'm " + this.name + " and I'm " + to_string(this.age) + " years old.";
    }

    fn birthday() {
        this.age = this.age + 1;
    }
}

let alice = Person("Alice", 30);
println(alice.greet());  // "Hello, I'm Alice and I'm 30 years old."

alice.birthday();
println(alice.greet());  // "Hello, I'm Alice and I'm 31 years old."

Inheritance

class Animal {
    fn init(name) {
        this.name = name;
    }

    fn speak() {
        return "Some sound";
    }
}

class Dog extends Animal {
    fn speak() {
        return this.name + " says: Woof!";
    }

    fn fetch(item) {
        return this.name + " fetches the " + item;
    }
}

let dog = Dog("Buddy");
println(dog.speak());           // "Buddy says: Woof!"
println(dog.fetch("ball"));     // "Buddy fetches the ball"

Error Handling

Try-Catch Blocks

fn divide(a, b) {
    try {
        if b == 0 {
            throw "Division by zero";
        }
        return a / b;
    } catch error {
        println("Error: " + error);
        return 0;
    }
}

println("Result: " + to_string(divide(10, 2)));  // "Result: 5"
println("Result: " + to_string(divide(10, 0)));  // "Error: Division by zero" then "Result: 0"

File Operations with Error Handling

fn read_file_safe(filename) {
    try {
        let content = read_file(filename);
        if content.startswith("Error") {
            throw "Failed to read file: " + content;
        }
        return content;
    } catch error {
        println("File operation failed: " + error);
        return "";
    }
}

let content = read_file_safe("data.txt");
if len(content) > 0 {
    println("File content: " + content);
}

File Operations

Reading and Writing Files

// Writing to a file
let data = "Hello, World!\nThis is a test file.";
let result = write_file("test.txt", data);
println("Write result: " + result);

// Reading from a file
let content = read_file("test.txt");
println("File content: " + content);

// Listing directory contents
let files = list_dir(".");
println("Files in current directory:");
for file in files {
    println("- " + file);
}

Processing CSV-like Data

// Create sample data
let csv_data = "Name,Age,City\nAlice,30,New York\nBob,25,Los Angeles\nCharlie,35,Chicago";
write_file("people.csv", csv_data);

// Read and process the data
let file_content = read_file("people.csv");
let lines = split(file_content, "\n");

println("People data:");
for i in 1..len(lines) {
    let fields = split(lines[i], ",");
    if len(fields) >= 3 {
        println(fields[0] + " is " + fields[1] + " years old and lives in " + fields[2]);
    }
}

Web Development

Simple Web Page

// Create a simple HTML page
let page_content = create_page(
    "My First Web Page",
    html_element("div", [
        html_element("h1", "Welcome to Veyra!"),
        html_element("p", "This is a simple web page created with Veyra."),
        html_element("ul", [
            html_element("li", "Easy to learn"),
            html_element("li", "Powerful features"),
            html_element("li", "Built-in web server")
        ])
    ]),
    "body { font-family: Arial, sans-serif; margin: 40px; background: #f5f5f5; }"
);

// Start web server
web_serve(page_content, 8080);
println("Server started at http://localhost:8080");

Interactive Web Application

// Create an interactive calculator
let calculator_html = create_page(
    "Calculator",
    html_element("div", {"id": "calculator"}, [
        html_element("input", "", {"type": "text", "id": "display", "readonly": "true"}),
        html_element("br"),
        html_element("button", "7", {"onclick": "appendNumber('7')"}),
        html_element("button", "8", {"onclick": "appendNumber('8')"}),
        html_element("button", "9", {"onclick": "appendNumber('9')"}),
        html_element("button", "+", {"onclick": "setOperation('+')"}),
        html_element("br"),
        html_element("button", "4", {"onclick": "appendNumber('4')"}),
        html_element("button", "5", {"onclick": "appendNumber('5')"}),
        html_element("button", "6", {"onclick": "appendNumber('6')"}),
        html_element("button", "-", {"onclick": "setOperation('-')"}),
        html_element("br"),
        html_element("button", "1", {"onclick": "appendNumber('1')"}),
        html_element("button", "2", {"onclick": "appendNumber('2')"}),
        html_element("button", "3", {"onclick": "appendNumber('3')"}),
        html_element("button", "*", {"onclick": "setOperation('*')"}),
        html_element("br"),
        html_element("button", "0", {"onclick": "appendNumber('0')"}),
        html_element("button", "C", {"onclick": "clearDisplay()"}),
        html_element("button", "=", {"onclick": "calculate()"}),
        html_element("button", "/", {"onclick": "setOperation('/')"})
    ]),
    "
    #calculator { width: 200px; margin: 50px auto; }
    button { width: 40px; height: 40px; margin: 2px; font-size: 18px; }
    #display { width: 190px; height: 30px; margin-bottom: 10px; font-size: 20px; text-align: right; }
    "
);

// Add JavaScript for calculator functionality
let js_code = "
let display = '';
let operation = null;
let previousValue = null;

function appendNumber(num) {
    display += num;
    document.getElementById('display').value = display;
}

function setOperation(op) {
    if (display !== '') {
        previousValue = parseFloat(display);
        operation = op;
        display = '';
    }
}

function calculate() {
    if (previousValue !== null && display !== '' && operation) {
        const currentValue = parseFloat(display);
        let result;
        switch(operation) {
            case '+': result = previousValue + currentValue; break;
            case '-': result = previousValue - currentValue; break;
            case '*': result = previousValue * currentValue; break;
            case '/': result = previousValue / currentValue; break;
        }
        display = result.toString();
        document.getElementById('display').value = display;
        operation = null;
        previousValue = null;
    }
}

function clearDisplay() {
    display = '';
    operation = null;
    previousValue = null;
    document.getElementById('display').value = '';
}
";

let full_page = calculator_html + "<script>" + js_code + "</script>";

// Start the web server
web_serve(full_page, 8081);
println("Calculator app running at http://localhost:8081");

AI/ML Examples

Matrix Operations

// Create matrices
let matrix_a = [
    [1, 2, 3],
    [4, 5, 6]
];

let matrix_b = [
    [7, 8],
    [9, 10],
    [11, 12]
];

// Matrix multiplication
let result = matrix_multiply(matrix_a, matrix_b);
println("Matrix multiplication result:");
for row in result {
    println(to_string(row));
}

Neural Network Components

// Simulate a simple neural network layer
let inputs = [0.5, 0.3, 0.8];
let weights = [0.2, 0.4, 0.6];
let bias = 0.1;

// Calculate weighted sum
let weighted_sum = bias;
for i in 0..len(inputs) {
    weighted_sum = weighted_sum + inputs[i] * weights[i];
}

// Apply activation function
let output = relu(weighted_sum);

println("Neural network output: " + to_string(output));

Linear Regression

// Sample data: house sizes vs prices
let sizes = [1000, 1200, 1500, 1800, 2000];
let prices = [200000, 240000, 300000, 360000, 400000];

// Train linear regression model
let model = ai_linear_regression(sizes, prices);

println("Linear regression model:");
println("Slope: " + to_string(model["slope"]));
println("Intercept: " + to_string(model["intercept"]));

// Make a prediction
let new_size = 1600;
let predicted_price = model["slope"] * new_size + model["intercept"];
println("Predicted price for 1600 sq ft house: $" + to_string(predicted_price));

Advanced Examples

Concurrent Programming with Channels

// Create a channel for communication
let chan = channel();

// Producer function (runs in background)
fn producer() {
    for i in 1..6 {
        send(chan, "Message " + to_string(i));
        sleep(0.5);  // Simulate work
    }
    send(chan, "DONE");
}

// Consumer function
fn consumer() {
    while true {
        let message = receive(chan);
        if message == "DONE" {
            break;
        }
        println("Received: " + message);
    }
}

// Start producer in background
producer();  // This would run in background in a real implementation

// Run consumer
consumer();

println("Concurrent example completed");

File Processing Pipeline

// Read data from file, process it, and write results
fn process_data() {
    try {
        // Read input data
        let input_data = read_file("input.txt");
        if input_data.startswith("Error") {
            throw "Failed to read input file";
        }

        // Process the data (convert to uppercase and count words)
        let processed = upper(input_data);
        let words = split(processed, " ");
        let word_count = len(words);

        // Create output
        let output = "Processed text:\n" + processed + "\n\nWord count: " + to_string(word_count);

        // Write results
        let write_result = write_file("output.txt", output);
        if write_result.startswith("Error") {
            throw "Failed to write output file";
        }

        println("Data processing completed successfully");
        println("Word count: " + to_string(word_count));

    } catch error {
        println("Error in data processing: " + error);
    }
}

process_data();

Web API Server

// Simple REST API server
fn create_api_response(data) {
    return json_stringify({
        "status": "success",
        "data": data,
        "timestamp": time_now()
    });
}

fn handle_get_users() {
    let users = [
        {"id": 1, "name": "Alice", "email": "[email protected]"},
        {"id": 2, "name": "Bob", "email": "[email protected]"},
        {"id": 3, "name": "Charlie", "email": "[email protected]"}
    ];
    return create_api_response(users);
}

fn handle_get_user(id) {
    let users = [
        {"id": 1, "name": "Alice", "email": "[email protected]"},
        {"id": 2, "name": "Bob", "email": "[email protected]"},
        {"id": 3, "name": "Charlie", "email": "[email protected]"}
    ];

    for user in users {
        if user["id"] == id {
            return create_api_response(user);
        }
    }

    return json_stringify({
        "status": "error",
        "message": "User not found",
        "timestamp": time_now()
    });
}

// Create API documentation page
let api_page = create_page(
    "Veyra API",
    html_element("div", [
        html_element("h1", "Veyra REST API"),
        html_element("h2", "Endpoints"),
        html_element("ul", [
            html_element("li", html_element("code", "GET /api/users") + " - Get all users"),
            html_element("li", html_element("code", "GET /api/users/{id}") + " - Get user by ID")
        ]),
        html_element("h2", "Example Responses"),
        html_element("pre", json_stringify({
            "status": "success",
            "data": [{"id": 1, "name": "Alice"}],
            "timestamp": 1234567890
        }, null, 2))
    ]),
    "body { font-family: monospace; margin: 40px; } code { background: #f4f4f4; padding: 2px 4px; }"
);

// Start the API server
web_serve(api_page, 3000);
println("API server running at http://localhost:3000");

These examples demonstrate the breadth of Veyra's capabilities, from basic programming constructs to advanced features like web development, AI/ML, and concurrent programming. For the complete list of built-in functions, see the Standard Library page. For language syntax details, see the Language Guide.

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