Function parseNameAndArgTypes

src/backend/utils/adt/regproc.c:1924–2062

* Given a C string, parse it into a qualified function or operator name * followed by a parenthesized list of type names. Reduce the * type names to an array of OIDs (returned into *nargs and *argtypes; * the argtypes array should be of size FUNC_MAX_ARGS). The function or * operator name is returned to *names as a List of Strings. * * If allowNone is true, accept "NONE" and return it as I

 * for unary operators).
 */
static void
parseNameAndArgTypes(const char *string, bool allowNone, List **names,
					 int *nargs, Oid *argtypes)
{
	char	   *rawname;
	char	   *ptr;
	char	   *ptr2;
	char	   *typename;
	bool		in_quote;
	bool		had_comma;
	int			paren_count;
	Oid			typeid;
	int32		typmod;

	/* We need a modifiable copy of the input string. */
	rawname = pstrdup(string);

	/* Scan to find the expected left paren; mustn't be quoted */
	in_quote = false;
	for (ptr = rawname; *ptr; ptr++)
	{
		if (*ptr == '"')
			in_quote = !in_quote;
		else if (*ptr == '(' && !in_quote)
			break;
	}
	if (*ptr == '\0')
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("expected a left parenthesis")));

	/* Separate the name and parse it into a list */
	*ptr++ = '\0';
	*names = stringToQualifiedNameList(rawname);

	/* Check for the trailing right parenthesis and remove it */
	ptr2 = ptr + strlen(ptr);
	while (--ptr2 > ptr)
	{
		if (!scanner_isspace(*ptr2))
			break;
	}
	if (*ptr2 != ')')
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("expected a right parenthesis")));

	*ptr2 = '\0';

	/* Separate the remaining string into comma-separated type names */
	*nargs = 0;
	had_comma = false;

	for (;;)
	{
		/* allow leading whitespace */
		while (scanner_isspace(*ptr))
			ptr++;