Bool* not_has_element(Variable* A, Variable* B)
{
    Bool* b = has_element(A, B);
    if(b == NULL)
        return NULL;
    b->setValue(!b->getValue());
    return b;
}
Variable* add_assign(Variable* A, Variable* B)
{
    if(A == NULL || B == NULL)
    {
        interpreter.error("Error: Void variable in assignment.\n");
        return NULL;
    }
    if(!A->reference)
    {
        interpreter.error("Error: Assigning value to a non-reference variable.\n");
        return NULL;
    }

    TypeEnum a = A->getType();
    TypeEnum b = B->getType();

    bool mismatch = false;
    if(a == STRING)
    {
        if(b != STRING)
            mismatch = true;
        else
        {
            String* C = static_cast<String*>(A);
            String* D = static_cast<String*>(B);
            C->setValue(C->getValue() + D->getValue());
        }
    }
    else if(a == INT)
    {
        if(b != BOOL && b != INT && b != FLOAT)
            mismatch = true;
        else
        {
            Int* C = static_cast<Int*>(A);
            if(b == BOOL)
            {
                Bool* D = static_cast<Bool*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
            else if(b == INT)
            {
                Int* D = static_cast<Int*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
            else
            {
                Float* D = static_cast<Float*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
        }
    }
    else if(a == FLOAT)
    {
        if(b != BOOL && b != INT && b != FLOAT)
            mismatch = true;
        else
        {
            Float* C = static_cast<Float*>(A);
            if(b == BOOL)
            {
                Bool* D = static_cast<Bool*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
            else if(b == INT)
            {
                Int* D = static_cast<Int*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
            else
            {
                Float* D = static_cast<Float*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
        }
    }
    else if(a == BOOL)
    {
        if(b != BOOL && b != INT && b != FLOAT)
            mismatch = true;
        else
        {
            Bool* C = static_cast<Bool*>(A);
            if(b == BOOL)
            {
                Bool* D = static_cast<Bool*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
            else if(b == INT)
            {
                Int* D = static_cast<Int*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
            else
            {
                Float* D = static_cast<Float*>(B);
                C->setValue(C->getValue() + D->getValue());
            }
        }
    }
    else if(a == MACRO)
    {
        interpreter.error("Error: Addition operation not defined for type 'macro'.\n");
        return NULL;
    }
    else if(a == ARRAY)
    {
        if(b == ARRAY)
        {
            Array* C = static_cast<Array*>(A);
            Array* D = static_cast<Array*>(B);
            a = C->getValueType();
            b = C->getValueType();
            if(a != b)
            {
                interpreter.error("Error: Types do not match in assignment: Array<%s> vs Array<%s>\n", C->getValueTypeString().c_str(), D->getValueTypeString().c_str());
                return NULL;
            }
            C->push_back(D->getValue());
        }
        else
        {
            Array* C = static_cast<Array*>(A);
            if(b == C->getValueType())
            {
                C->push_back(B);
            }
            else
                mismatch = true;
        }
    }
    else if(a == LIST)
    {
        // Lists must be concatenated a different way...
        List* C = static_cast<List*>(A);
        C->push_back(B);
    }
    else if(a == FUNCTION)
    {
        interpreter.error("Error: Addition operation not defined for type 'function'.\n");
        return NULL;
    }
    else if(a == PROCEDURE)
    {
        interpreter.error("Error: Addition operation not defined for type 'procedure'.\n");
        return NULL;
    }

    if(mismatch)
    {
        interpreter.error("Error: Types do not match in assignment: %s vs %s\n", A->getTypeString().c_str(), B->getTypeString().c_str());
        return NULL;
    }
    return A;
}
Variable* assign(Variable* A, Variable* B)
{
    if(A == NULL || B == NULL)
    {
        interpreter.error("Error: Void variable in assignment.\n");
        return NULL;
    }
    if(!A->reference)
    {
        interpreter.error("Error: Assigning value to a non-reference variable.\n");
        return NULL;
    }

    TypeEnum a = A->getType();
    TypeEnum b = B->getType();

    bool mismatch = false;
    if(a == STRING)
    {
        if(b != STRING)
            mismatch = true;
        else
        {
            String* C = static_cast<String*>(A);
            String* D = static_cast<String*>(B);
            C->setValue(D->getValue());
        }
    }
    else if(a == INT)
    {
        if(b != BOOL && b != INT && b != FLOAT)
            mismatch = true;
        else
        {
            Int* C = static_cast<Int*>(A);
            if(b == BOOL)
            {
                Bool* D = static_cast<Bool*>(B);
                C->setValue(D->getValue());
            }
            else if(b == INT)
            {
                Int* D = static_cast<Int*>(B);
                C->setValue(D->getValue());
            }
            else
            {
                Float* D = static_cast<Float*>(B);
                C->setValue(D->getValue());
            }
        }
    }
    else if(a == FLOAT)
    {
        if(b != BOOL && b != INT && b != FLOAT)
            mismatch = true;
        else
        {
            Float* C = static_cast<Float*>(A);
            if(b == BOOL)
            {
                Bool* D = static_cast<Bool*>(B);
                C->setValue(D->getValue());
            }
            else if(b == INT)
            {
                Int* D = static_cast<Int*>(B);
                C->setValue(D->getValue());
            }
            else
            {
                Float* D = static_cast<Float*>(B);
                C->setValue(D->getValue());
            }
        }
    }
    else if(a == BOOL)
    {
        if(b != BOOL && b != INT && b != FLOAT)
            mismatch = true;
        else
        {
            Bool* C = static_cast<Bool*>(A);
            if(b == BOOL)
            {
                Bool* D = static_cast<Bool*>(B);
                C->setValue(D->getValue());
            }
            else if(b == INT)
            {
                Int* D = static_cast<Int*>(B);
                C->setValue(D->getValue());
            }
            else
            {
                Float* D = static_cast<Float*>(B);
                C->setValue(D->getValue());
            }
        }
    }
    else if(a == MACRO)
    {
        if(b != MACRO)
            mismatch = true;
        else
        {
            Macro* C = static_cast<Macro*>(A);
            Macro* D = static_cast<Macro*>(B);
            C->setValue(D->getValue());
        }
    }
    else if(a == ARRAY)
    {
        if(b != ARRAY)
            mismatch = true;
        else
        {
            Array* C = static_cast<Array*>(A);
            Array* D = static_cast<Array*>(B);
            a = C->getValueType();
            b = D->getValueType();
            if(a != b)
            {
                interpreter.error("Error: Types do not match in assignment: Array<%s> vs Array<%s>\n", C->getValueTypeString().c_str(), D->getValueTypeString().c_str());
                return NULL;
            }
            C->setValue(D->getValue());
        }
    }
    else if(a == LIST)
    {
        if(b != LIST)
            mismatch = true;
        else
        {
            List* C = static_cast<List*>(A);
            List* D = static_cast<List*>(B);
            C->setValue(D->getValue());
        }
    }
    else if(a == FUNCTION)
    {
        if(b != FUNCTION)
            mismatch = true;
        else
        {
            Function* C = static_cast<Function*>(A);
            Function* D = static_cast<Function*>(B);
            C->setValue(D->getValue());
        }
    }
    else if(a == PROCEDURE)
    {
        if(b != PROCEDURE)
            mismatch = true;
        else
        {
            Procedure* C = static_cast<Procedure*>(A);
            Procedure* D = static_cast<Procedure*>(B);
            C->setValue(D->getValue());
        }
    }

    if(mismatch)
    {
        interpreter.error("Error: Types do not match in assignment: %s vs %s\n", A->getTypeString().c_str(), B->getTypeString().c_str());
        return NULL;
    }
    return A;
}