Your First Program

Create a file named hello.yl:

function main() -> int {
    let const string name = "YLang";
    print("Hello from", name);
    print("The answer is", 40 + 2);
    return 0;
}

The program defines the main function, creates a constant string, prints two lines, and returns an integer exit status.

Check, build, and run

From the repository root:

./build/ylang check hello.yl
./build/ylang build hello.yl -o hello
./hello

The first command checks the source without producing an executable. The second uses the default C backend and invokes a C compiler to build the native program. The final command runs it.

On Windows, the compiler executable is normally build/ylang.exe; the output program should use a Windows executable name such as hello.exe.

What if it fails?

Read the complete diagnostic, including its error code. Check punctuation, declared types, and the compiler command before changing the program. The Compiler Error Codes page explains stable diagnostic identifiers.

Try one change

Change the value of name, or replace 40 + 2 with a different integer expression. Run the same check/build/run sequence again. The point is to build a habit: check the source first, then compile it, then run the output.