Writing a Hello World in Glu

The traditional hello world program is the first program that we will write in Glu. This program will print the string “Hello, World!” to the console.

Creating a Project Directory

First, create a directory for the project.

mkdir hello-world
cd hello-world

Creating a Source File

Create a file named main.glu in the project directory.

touch main.glu

Writing the Hello World Program

Open the main.glu file in a text editor. To make a hello world program in Glu, this is the code.

func main() {
    std::print("Hello, World!");
}

Save the file.

Compiling the Program

To compile the program, run the following command in the terminal.

gluc main.glu

This will create an executable file named main in the project directory.

You can run the executable by running the following command.

# Linux or macOS
./main
# Windows
.\main.exe

Anatomy of the Program

The program consists of a single function main. Any executable needs a function main to run.

func main() {

}

The main function is a special function that is called when the program is run. Here, we declare a function named main that takes no arguments and returns nothing. If the function had any arguments, they would be listed inside the parentheses. If the function returned a value, the return type would be specified after the parentheses, after an arrow ->.

The body of the function is enclosed in curly braces {}. All function definitions in Glu have a body that contains the statements that are executed when the function is called.

In this case, the body contains a single statement that calls the std::print function to print the string “Hello, World!” to the console.

std::print("Hello, World!");

The std::print function is a standard library function that prints the given string to the console. The function is named print and is part of the std module, which is the standard library module that contains various utility functions. The std module is imported by default in all Glu programs, so we can use its functions without explicitly importing it. The :: operator is used to access functions and variables in modules. In this case, we use it to access the print function in the std module.

The std::print function takes a single argument, which is the string to be printed. A new line character is automatically added to the end of the string when it is printed.

The string is enclosed in double quotes "" to indicate that it is a string literal. String literals are sequences of characters enclosed in double quotes that represent text. They are used to represent text.