org.jruby.compiler.ir.operands.UnexecutableNil Maven / Gradle / Ivy

package org.jruby.compiler.ir.operands;

import org.jruby.interpreter.InterpreterContext;
import org.jruby.runtime.builtin.IRubyObject;

// This operand is used to represent the result of an explicit return instruction.
// So, "return " will return this operand so ruby expressions like
//    "foo || return false" 
// have something in the second slot of the || instruction.  But since control flow
// can never go beyond the return, this value itself can never be interpreted or executed.
// It exists only to fulfil the needs of IR to not have null operands.
public class UnexecutableNil extends Nil {
    public static final UnexecutableNil U_NIL = new UnexecutableNil();

    private UnexecutableNil() { }

    @Override
    public String toString() { 
        return "nil(unexecutable)";
    }

    @Override
    public Operand fetchCompileTimeArrayElement(int argIndex, boolean getSubArray) { 
        return U_NIL;
    }

    @Override
    public Object retrieve(InterpreterContext interp) {
        throw new RuntimeException(this.getClass().getSimpleName() + " should not be directly interpreted");
    }
}