[begin_label:] LOOP statement_list END LOOP [end_label]
LOOP implements a simple loop construct, enabling repeated execution
of the statement list, which consists of one or more statements, each
terminated by a semicolon (i.e.,
;) statement delimiter. The statements
within the loop are repeated until the loop is exited; usually this is
accomplished with a LEAVE statement.
LOOP statement can be labeled.
end_label cannot be given unless
begin_label also is present. If both are present, they must be the