starts with two adjacent hyphens and extends up to the end of the line.
may appear on any line of a program.
The presence or absence of comment
has no influence on whether a program is legal or illegal. Furthermore,
not influence the meaning of a program; their sole purpose is the enlightenment
of the human reader.
Examples of comments:
-- the last sentence above echoes the Algol 68 report
end; -- processing of Line is complete
-- a long comment may be split onto
-- two or more consecutive lines
---------------- the first two hyphens start the comment