A comment starts with two adjacent hyphens and extends up to the end of the line. A comment can appear on any line of a program. The presence or absence of comments has no influence on whether a program is legal or illegal. Furthermore, comments do not influence the effect of a program; their sole purpose is the enlightenment of the human reader.


    --  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  


Horizontal tabulation can be used in comments, after the double hyphen, and is equivalent to one or more spaces (see 2.2).

References: end of a line, illegal, legal, space character.