Function json_lex_number

src/common/jsonapi.c:915–1008

* The next token in the input stream is known to be a number; lex it. * * In JSON, a number consists of four parts: * * (1) An optional minus sign ('-'). * * (2) Either a single '0', or a string of one or more digits that does not * begin with a '0'. * * (3) An optional decimal part, consisting of a period ('.') followed by * one or more digits. (Note: While this part can be omitt

 * the distance from lex->input to the token end+1 is returned to *total_len.
 */
static inline JsonParseErrorType
json_lex_number(JsonLexContext *lex, char *s,
				bool *num_err, int *total_len)
{
	bool		error = false;
	int			len = s - lex->input;

	/* Part (1): leading sign indicator. */
	/* Caller already did this for us; so do nothing. */

	/* Part (2): parse main digit string. */
	if (len < lex->input_length && *s == '0')
	{
		s++;
		len++;
	}
	else if (len < lex->input_length && *s >= '1' && *s <= '9')
	{
		do
		{
			s++;
			len++;
		} while (len < lex->input_length && *s >= '0' && *s <= '9');
	}
	else
		error = true;

	/* Part (3): parse optional decimal portion. */
	if (len < lex->input_length && *s == '.')
	{
		s++;
		len++;
		if (len == lex->input_length || *s < '0' || *s > '9')
			error = true;
		else
		{
			do
			{
				s++;
				len++;
			} while (len < lex->input_length && *s >= '0' && *s <= '9');
		}
	}

	/* Part (4): parse optional exponent. */
	if (len < lex->input_length && (*s == 'e' || *s == 'E'))
	{
		s++;
		len++;
		if (len < lex->input_length && (*s == '+' || *s == '-'))
		{
			s++;
			len++;
		}
		if (len == lex->input_length || *s < '0' || *s > '9')
			error = true;
		else
		{