@Section
   @Title { Embedding Lout commands within program comments }
   @Tag { cpcomm }
@Begin
@PP
It is possible to embed Lout text inside program comments.  How this
is done could in principle vary from language to language, but in
every language supported so far it is done by starting off the comment
with an @Code "@" character.  If the language has several ways to get
a comment, this will work every way.  The entire comment after the @Code "@"
character should then be Lout text.  For example, to force Lout to start
a new page at some point within a C program, place
@ID @Code "/*@ @NP */"
at that point.  (In this case you can also simply include a formfeed
formfeed. @Index { formfeed in program texts }
character, control-L, without any comment; whatever the language, a formfeed
in program text is taken to be a request to start a new page.)  Or, to
make a heading in an Eiffel program, do this:
@ID @Code "--@ @Display @Heading { treeprint() }"
(Eiffel comments begin with @Code "--" and end at the end of the
line.)  Other possible uses for this feature include index entries and
margin notes.  Incredible as it may seem, you can even write
@ID @Code "/*@ @CD @Heading { Function @CP { treeprint() } } */"
with a @Code "@CP" symbol and some C code inside the Lout code
inside the C code.  You probably can't go further, however, at least
not in C, since that would require a C comment inside a C comment.
@End @Section