Hello World

As stated previously xyc is just the compiler, no libraries included. So to print anything on the screen first we need to install a library that gives us this functionality.

Standard libraries that come prepackaged with the compiler (or OS) can be very useful. They lower the barrier to entry into the language as it is one less thing to install and worry about. Unfortunately they tend to

• Overgrow and include all sort of functionality that can easily be left to a “normal” library.
• Merge with the language or compiler which is just laziness on the side of the language developers who instead of defining general features available to all they do niche solutions and gate them behind compiler extension.
• Be slow to change as they usually require the same rigorous specification as the programming language itself.

Installing Dependencies

libxy is the closes thing to a standard library available to XY programmer. It includes common functionality like functions for console output. Let’s install it.

# first create a folder that is going to serve as the base of all examples
mkdir xy-tutorial
cd xy-tutorial
# make a dir for our dependencies
mkdir libs

Now that the basic structure is in place installing libxy (or any other library) is as simple as

git clone --depth 1 -b stable https://github.com/xy-org/libxy.git libs/libxy

Finally Printing Out a Message

Create a file helloworld.xy with the following content

import libxy.stdio;
import libxy.string;

def main~EntryPoint() -> int {
    print("Hello World\n");
    return 0;
}

And then to compile:

xyc helloworld.xy -L libs/
./helloworld

You should see the message Hello World. If you do 🥳. Else complain to the developers by submitting an issue or struggle!

Explanation

The example is simple but it showcases a lot of the features and ideas of XY. Let’s dissect it line by line.

import libxy.stdio; - this imports the stdio module from libxy. It is the module that contains the print function. XY has structured modules with submodules and so on (instead of header files and compiler magic like C).

import libxy.string; - XY doesn’t have builtin strings. This means we have to import a library that implements them for us.

def main~EntryPoint() -> int { - defines a function called main tagged as EntryPoint that returns int. More about tags latter.

print("Hello World\n"); - this line is self explanatory - it calls the function print with the string `Hello World\n”

Peaking Under the Hood

xyc works as a source-to-source compiler. It compiles XY source code to C and then compiles the C code to an executable. To get just the C code run:

xyc -c helloworld.xy -L libs/
cat helloworld.c

Enjoy!