martinschneider / orzo

Java compiler written in Java

Orzo is a Java-based language for the JVM.

It's named after my beverage of choice while coding it.

Features

✨ Orzo-only features (not available in Java)

Types

• primitive types (byte, short, int, char, boolean, long, float, double)
• one-dimensional arrays
• String
• interfaces
• reference types (partially supported)
• enums (partially supported)
• class inheritance
• exceptions
• multi-dimensional arrays

Operators

• assignment =
• parallel assignment ✨
• parallel declarations, e.g. int a,b,c,d,e,f = 1,2,3 ✨
• repeat ✨
• arithmetic +, -, *, /, %
• ** power operator ✨, e.g. int b = a ** 5
• √ sqrt operator ✨, e.g. double x = √n + √(n+1)
• parenthesis ( ,)
• unary post/pre-increment and decrement ++, --
• compound assignments +=, -=, *=, /=, %=, <<=, >>=, >>>=, &=, ^=, |=
• relational <, <=, >=, >
• equality ==, !=,
• bit &, ^, |, <<, >>, >>>
• unary minus -
• casting () (partially supported)
• object creation new (partially supported)
• logical &&, ||
• unary logical !
• unary bitwise ~
• unary plus +
• instanceof
• String and char concatenation +
• ternary ?:

Control strcutures

• if, else if and else
• while
• do
• for
• break
• return
• method and constructor calls (partially supported)
• continue
• try
• switch
• lambdas
• unless ✨

Notes

• array defintions must be of the form int[] a, int a[] is not supported
• Orzo creates class files with major version 50 (Java 6). Newer versions would require implementation of the StackMapTable attribute.
• fields and variables share the same namespace

Example

Calculating π using the Gauss-Legendre algorithm:

public double pi(int n) {
  double a, b, t, p, x = 1, 1/√2, 1/4, 1;
  repeat n
  {
    x, a, b  =  a, (a + b) / 2, √(x*b);
    t, p     =  t - p * ((x-a) ** 2), 2 * p;
  }
  return ((a+b) ** 2) / (4 * t);
}

More examples can be found here.

Build

with mvn

mvn package

with javac and jar

javac $(find ./src/main/java -name "*.java") -d bin && jar cfe orzo.jar io.github.martinschneider.orzo.Orzo -C bin .

Usage

java -jar target/orzo.jar inputFiles -d outputFolder