ASTDeref.java

public class ASTDeref implements ASTNode {
    ASTNode exp;

    public ASTDeref(ASTNode exp) {
        this.exp = exp;
    }
    
    @Override
	public IValue eval(Environment<IValue> e) throws InterpreterError
    {
        IValue v = exp.eval(e);
        if (v instanceof MemoryManager.VAddress addr) {
            try {
                return ASTLet.mem.memrd(addr);
            } catch (MemoryPanicError ex) {
                throw new InterpreterError("mut: " + ex.getMessage());
            }
        } else if (v instanceof VCell cell) {
            return cell.getval();
        }
        throw new InterpreterError("! operator: reference or addr expected, " + v + " found.");
    }

    @Override
    public ASTType typecheck(Environment<ASTType> env) throws TypeCheckError, InterpreterError {
        ASTType t = exp.typecheck(env);
        if (t instanceof ASTTRef ref) {
            return ASTTypeDef.unfold(ref.getType(), env);
        } else if (t instanceof ASTTAddr addr) {
            return ASTTypeDef.unfold(addr.getType(), env);
        }
        throw new TypeCheckError("Deref: expected a reference");
    }

    @Override
    public boolean isFreeOutsideLambda(String id) {
		return exp.isFreeOutsideLambda(id);
	}

}