1 A comment starts with two adjacent hyphens and extends up to the end of the line.
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:
-- 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
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.