Instructions Idea

gistfile1.java

public interface Instruction {

    /** Executes an instruction on the Machine.
     * @param m The machine upon which to execute the instruction.
     * @return true if the executed instruction modified a general purpose register.
     */
    public boolean execute(Machine m);

}

public class AddImmediate implements Instruction {

    private final Register dest;
    private final Register src;
    private final short immediate;

    public AddImmediate(Register dest, Register src, short immediate) {
        this.dest = dest;
        this.src = src;
        this.immediate = immediate;
    }

    public boolean execute(Machine m) {
        m.setRegister(this.dest, this.src.get() + this.immediate);
        return true;
    }

}

public class DebugInstruction implements Instruction {

    public boolean execute(Machine m) {
        m.Syscalls.showDebug(m);
        return false;
    }
}

public class TrapOUTN implements Instruction {

    public boolean execute(Machine m) {
        m.Syscalls.outN(m.getRegister(RegisterBank.R0));
        return false;
    }
}

public class Interpreter {

    // ...

    public void runInstruction(String rawInstruction) {
        Instruction instruction = this.parser.parse(rawInstruction);
        boolean wroteToRegBank = instruction.execute(this.machine);
        // ...
    }

}