1 A comment starts with two adjacent hyphens and extends up to the end of the line.
2 comment ::= --{non_end_of_line_character}
3 A comment may appear on any line of a program.
4 The presence or absence of comments has no influence on whether a program is legal or illegal. Furthermore, comments do not influence the meaning of a program; their sole purpose is the enlightenment of the human reader.
5 Examples of comments:
6
-- 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
[aada]
As with the entire input text of a program, the UTF-8 input will be checked for normalization. If errors are detected, even within a comment, an error ensues. As for strings, a specific pragma allows for non-normalized characters in comments.
AAda understands the C++ comment introducer, a double slash (//), as such. It still generates an error as it is not correct in Ada.
AAda understands the shell comment introducer, a hash character (#), as such when the character is not preceeded by a digits (0-9). It still generates an error as it is not correct in Ada.
AAda detects the old Pascal comment introducer: (* and generates an error about it. It does not try to skip the comment.
AAda detects the C/C++ multi-line comment introducer /* and generates an error about it. It does not try to skip the comment.
[/aada]