Function ParseDecimalComponents

cpp/src/arrow/util/decimal.cc:820–860

}

bool ParseDecimalComponents(const char* s, size_t size, DecimalComponents* out) {
  size_t pos = 0;

  if (size == 0) {
    return false;
  }
  // Sign of the number
  if (IsSign(s[pos])) {
    out->sign = *(s + pos);
    ++pos;
  }
  // First run of digits
  pos = ParseDigitsRun(s, pos, size, &out->whole_digits);
  if (pos == size) {
    return !out->whole_digits.empty();
  }
  // Optional dot (if given in fractional form)
  bool has_dot = IsDot(s[pos]);
  if (has_dot) {
    // Second run of digits
    ++pos;
    pos = ParseDigitsRun(s, pos, size, &out->fractional_digits);
  }
  if (out->whole_digits.empty() && out->fractional_digits.empty()) {
    // Need at least some digits (whole or fractional)
    return false;
  }
  if (pos == size) {
    return true;
  }
  // Optional exponent
  if (StartsExponent(s[pos])) {
    ++pos;
    if (pos != size && s[pos] == '+') {
      ++pos;
    }
    out->has_exponent = true;
    return internal::ParseValue<Int32Type>(s + pos, size - pos, &(out->exponent));
  }
  return pos == size;
}

template <typename Decimal>
Status DecimalFromString(const char* type_name, std::string_view s, Decimal* out,