19.2.10.3. LOOP Statement
[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. The statements within the
loop are repeated until the loop is exited; usually this is
accomplished with a LEAVE statement.
A LOOP statement can be labeled.
end_label cannot be given unless
begin_label also is present. If
both are present, they must be the same.
