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result_t parse_float(ml_reader_base& rdr, const char** current, float* result) {
    char* end = NULL;
    double res = 0.0, sign = 1.0;
    long long intPart = 0, fracPart = 0;
    int fracCount = 0;
    long expPart = 0;
    char expNeg = 0;
    char hasIntPart = 0, hasFracPart = 0, hasExpPart = 0;
    int state = 0;
    // Parse optional sign
    if (**current == '+') {
        (*current)++;
    } else if (**current == '-') {
        sign = -1;
        (*current)++;
    }
    
    while (state<7) {
        if (**current) {
            switch (state) {
                case 0: // int part
                    if (!isdigit(**current)) {
                        state = 1;
                        break;
                    }
                    hasIntPart=1;
                    intPart = (intPart*10)+(**current-'0');
                    ++(*current);
                    break;
                case 1:
                    *result = (float)intPart;
                    if(**current!='.') {
                        state = 3;
                        break;
                    }
                    ++(*current);
                    state = 2;
                    break;
                case 2: // frac part
                    if (!isdigit(**current)) {
                        state = 3;
                        break;
                    }
                    ++fracCount;
                    hasFracPart=1;
                    fracPart = (fracPart*10)+(**current-'0');
                    ++(*current);
                    break;
                case 3:
                    if(hasFracPart) {
                        *result += (double)fracPart/pow(10.0,(double)fracCount);
                    }
                    if(**current=='E' || **current=='e') {
                        ++(*current);
                        state = 4;
                    } else {
                        state = 6;
                    }
                    break;
                case 4:
                    if(**current=='+') {
                        ++(*current);
                    }
                    if(**current=='-') {
                        expNeg = 1;
                        ++(*current);
                    }
                    state = 5;
                    break;
                case 5: 
                    if (!isdigit(**current)) {
                        state = 6;
                        break;
                    }
                    hasExpPart=1;
                    expPart = (expPart*10)+(**current-'0');
                    ++(*current);
                    break;
                case 6:
                    if(hasExpPart) {
                        if(expNeg) {
                            expPart = -expPart;
                        }
                        *result *= pow(10.0,(double)expPart);
                    }
                    *result*=sign;
                    state = 7;
                    break;
            }

        } else {
            if (!rdr.read()) {
                return IO_ERROR;
            }
            if (!rdr.has_value()) {
                *current = nullptr;
                break;
            }
            *current = rdr.value();
        }
    }
    if (rdr.node_type() == ml_node_type::attribute_end) {
        if (!rdr.read()) {
            return IO_ERROR;
        }
    }
    if(!hasIntPart&&!hasFracPart) {
        return FMT_ERROR;
    }
    return SUCCESS;
}