Function parse_ident

src/backend/utils/adt/misc.c:712–844

* parse_ident - parse a SQL qualified identifier into separate identifiers. * When strict mode is active (second parameter), then any chars after * the last identifier are disallowed. */

 * the last identifier are disallowed.
 */
Datum
parse_ident(PG_FUNCTION_ARGS)
{
	text	   *qualname = PG_GETARG_TEXT_PP(0);
	bool		strict = PG_GETARG_BOOL(1);
	char	   *qualname_str = text_to_cstring(qualname);
	ArrayBuildState *astate = NULL;
	char	   *nextp;
	bool		after_dot = false;

	/*
	 * The code below scribbles on qualname_str in some cases, so we should
	 * reconvert qualname if we need to show the original string in error
	 * messages.
	 */
	nextp = qualname_str;

	/* skip leading whitespace */
	while (scanner_isspace(*nextp))
		nextp++;

	for (;;)
	{
		char	   *curname;
		bool		missing_ident = true;

		if (*nextp == '"')
		{
			char	   *endp;

			curname = nextp + 1;
			for (;;)
			{
				endp = strchr(nextp + 1, '"');
				if (endp == NULL)
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
							 errmsg("string is not a valid identifier: \"%s\"",
									text_to_cstring(qualname)),
							 errdetail("String has unclosed double quotes.")));
				if (endp[1] != '"')
					break;
				memmove(endp, endp + 1, strlen(endp));
				nextp = endp;
			}
			nextp = endp + 1;
			*endp = '\0';

			if (endp - curname == 0)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
						 errmsg("string is not a valid identifier: \"%s\"",
								text_to_cstring(qualname)),
						 errdetail("Quoted identifier must not be empty.")));

			astate = accumArrayResult(astate, CStringGetTextDatum(curname),
									  false, TEXTOID, CurrentMemoryContext);
			missing_ident = false;