☰ H20

Getting Started

H20 is the same as Java but better literally, no extra twists.

• The default access modifier is private
• Variables are immutable by default. Use mut to allow changes
• Modifiers apply to members and functions, except main(), which is always public
• H20 supports C++ headers via include, but C++ functions are not allowed
• You still need to manage memory manually

Basic Keywords

• C++ Keywords:
  • include, includeNext, define, ifdef, endif, pragma, delete
• C++ Functions:
  • free(), memalloc()
• Access Modifiers:
  • public, private
• H20:
  • Primitives: int, float, boolean, String
  • Core Keywords: class, func, mut, use, new, if / else / elif, for, return
  • Functions: print()

Optional Output Flags

Single file mode only:

• --output-cpp - outputs the generated C++ file instead of compiling
• --output-assembly - outputs the generated assembly

Your First Program

1. Place H20.exe in your source folder
2. Create HelloWorld.h20:

   public class HelloWorld {
       func main() {
           printLn("Hello World!")
       }
   }

3. Run in your UCRT64 terminal: >

   > ./h20.exe HelloWorld.h20

Project Mode

Note: Output flags are disabled in project mode

1. Create a folder named src.
2. Place H20.exe in the root directory
3. Create main.txt containing your main class name: Main
4. Add source files to src/:

   src/HelloWorld.h20

   public class HelloWorld {
       func hi() {
           for (mut int i = 1; i < 100; i++) {
               print(i)
           }
       }
   }

   src/Main.h20

   use HelloWorld
   
   public class Main {
       func main() {
           HelloWorld hi = new HelloWorld()
           hi.hi()
       }
   }

5. Execute via terminal: >

   > ./h20.exe -project main.txt