Function svtod

lib/swoc/src/TextView.cc:153–230

}

double
svtod(swoc::TextView text, swoc::TextView *parsed) {
  // @return 10^e
  auto pow10 = [](int e) -> double {
    double zret  = 1.0;
    double scale = 10.0;
    if (e < 0) { // flip the scale and make @a e positive.
      e     = -e;
      scale = 0.1;
    }

    // Walk the bits in the exponent @a e and multiply the scale for set bits.
    while (e) {
      if (e & 1) {
        zret *= scale;
      }
      scale  *= scale;
      e     >>= 1;
    }
    return zret;
  };

  if (text.empty()) {
    return 0;
  }

  auto org_text = text; // save this to update @a parsed.
  // Check just once and dump to a local copy if needed.
  TextView local_parsed;
  if (!parsed) {
    parsed = &local_parsed;
  }

  // Handle leading sign.
  int sign = 1;
  if (*text == '-') {
    ++text;
    sign = -1;
  } else if (*text == '+') {
    ++text;
  }
  // Parse the leading whole part as an integer.
  intmax_t whole = svto_radix<10>(text);
  parsed->assign(org_text.data(), text.data());

  if (text.empty()) {
    return whole;
  }

  double frac = 0.0;
  if (*text == '.') { // fractional part.
    ++text;
    double scale = 0.1;
    while (text && isdigit(*text)) {
      frac  += scale * (*text++ - '0');
      scale /= 10.0;
    }
  }