static bool parseDecimal(IParser::Pos & pos, IParser::Pos end, ASTSampleRatio::Rational & res, IParser::Pos & max_parsed_pos)
{
ParserWhitespaceOrComments ws;
ws.ignore(pos, end);
UInt64 num_before = 0;
UInt64 num_after = 0;
Int64 exponent = 0;
IParser::Pos pos_after_first_num = tryReadIntText(num_before, pos, end);
bool has_num_before_point = pos_after_first_num > pos;
pos = pos_after_first_num;
bool has_point = pos < end && *pos == '.';
if (has_point)
++pos;
if (!has_num_before_point && !has_point)
return false;
size_t number_of_digits_after_point = 0;
if (has_point)
{
IParser::Pos pos_after_second_num = tryReadIntText(num_after, pos, end);
number_of_digits_after_point = pos_after_second_num - pos;
pos = pos_after_second_num;
}
bool has_exponent = pos < end && (*pos == 'e' || *pos == 'E');
if (has_exponent)
{
++pos;
IParser::Pos pos_after_exponent = tryReadIntText(exponent, pos, end);
if (pos_after_exponent == pos)
return false;
pos = pos_after_exponent;
}
res.numerator = num_before * exp10(number_of_digits_after_point) + num_after;
res.denominator = exp10(number_of_digits_after_point);
if (exponent > 0)
res.numerator *= exp10(exponent);
if (exponent < 0)
res.denominator *= exp10(-exponent);
/// NOTE You do not need to remove the common power of ten from the numerator and denominator.
return true;
}
static bool parseDecimal(IParser::Pos & pos, IParser::Pos end, ASTSampleRatio::Rational & res, IParser::Pos & max_parsed_pos)
{
ParserWhiteSpaceOrComments ws;
ws.ignore(pos, end);
UInt64 num_before = 0;
UInt64 num_after = 0;
Int64 exponent = 0;
IParser::Pos pos_after_first_num = tryReadIntText(num_before, pos, end);
bool has_num_before_point = pos_after_first_num > pos;
pos = pos_after_first_num;
bool has_point = pos < end && *pos == '.';
if (has_point)
++pos;
if (!has_num_before_point && !has_point)
return false;
size_t number_of_digits_after_point = 0;
if (has_point)
{
IParser::Pos pos_after_second_num = tryReadIntText(num_after, pos, end);
number_of_digits_after_point = pos_after_second_num - pos;
pos = pos_after_second_num;
}
bool has_exponent = pos < end && (*pos == 'e' || *pos == 'E');
if (has_exponent)
{
++pos;
IParser::Pos pos_after_exponent = tryReadIntText(exponent, pos, end);
if (pos_after_exponent == pos)
return false;
pos = pos_after_exponent;
}
res.numerator = num_before * exp10(number_of_digits_after_point) + num_after;
res.denominator = exp10(number_of_digits_after_point);
if (exponent > 0)
res.numerator *= exp10(exponent);
if (exponent < 0)
res.denominator *= exp10(-exponent);
/// NOTE Удаление общих степеней десяти из числителя и знаменателя - не нужно.
return true;
}
bool ParserUnsignedInteger::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
Field res;
Pos begin = pos;
if (pos == end)
return false;
UInt64 x = 0;
ReadBuffer in(const_cast<char *>(pos), end - pos, 0);
if (!tryReadIntText(x, in) || in.count() == 0)
{
expected = "unsigned integer";
return false;
}
res = x;
pos += in.count();
node = std::make_shared<ASTLiteral>(StringRange(begin, pos), res);
return true;
}
