Function json_lex

src/common/jsonapi.c:525–674

* Lex one token from the input stream. */

 * Lex one token from the input stream.
 */
JsonParseErrorType
json_lex(JsonLexContext *lex)
{
	char	   *s;
	int			len;
	JsonParseErrorType result;

	/* Skip leading whitespace. */
	s = lex->token_terminator;
	len = s - lex->input;
	while (len < lex->input_length &&
		   (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r'))
	{
		if (*s++ == '\n')
		{
			++lex->line_number;
			lex->line_start = s;
		}
		len++;
	}
	lex->token_start = s;

	/* Determine token type. */
	if (len >= lex->input_length)
	{
		lex->token_start = NULL;
		lex->prev_token_terminator = lex->token_terminator;
		lex->token_terminator = s;
		lex->token_type = JSON_TOKEN_END;
	}
	else
	{
		switch (*s)
		{
				/* Single-character token, some kind of punctuation mark. */
			case '{':
				lex->prev_token_terminator = lex->token_terminator;
				lex->token_terminator = s + 1;
				lex->token_type = JSON_TOKEN_OBJECT_START;
				break;
			case '}':
				lex->prev_token_terminator = lex->token_terminator;
				lex->token_terminator = s + 1;
				lex->token_type = JSON_TOKEN_OBJECT_END;
				break;
			case '[':
				lex->prev_token_terminator = lex->token_terminator;
				lex->token_terminator = s + 1;
				lex->token_type = JSON_TOKEN_ARRAY_START;
				break;
			case ']':
				lex->prev_token_terminator = lex->token_terminator;
				lex->token_terminator = s + 1;
				lex->token_type = JSON_TOKEN_ARRAY_END;
				break;
			case ',':
				lex->prev_token_terminator = lex->token_terminator;
				lex->token_terminator = s + 1;