Function gather_boolean_expression

src/bin/psql/command.c:2863–2883

* Read a boolean expression, return it as a PQExpBuffer string. * * Note: anything more or less than one token will certainly fail to be * parsed by ParseVariableBool, so we don't worry about complaining here. * This routine's return data structure will need to be rethought anyway * to support likely future extensions such as "\if defined VARNAME". */

 * to support likely future extensions such as "\if defined VARNAME".
 */
static PQExpBuffer
gather_boolean_expression(PsqlScanState scan_state)
{
	PQExpBuffer exp_buf = createPQExpBuffer();
	int			num_options = 0;
	char	   *value;

	/* collect all arguments for the conditional command into exp_buf */
	while ((value = psql_scan_slash_option(scan_state,
										   OT_NORMAL, NULL, false)) != NULL)
	{
		/* add spaces between tokens */
		if (num_options > 0)
			appendPQExpBufferChar(exp_buf, ' ');
		appendPQExpBufferStr(exp_buf, value);
		num_options++;
		free(value);
	}

	return exp_buf;
}

/*
 * Read a boolean expression, return true if the expression