Kdtyjb

In LaTeX, % can be used for single-line comments. For multi-line comments, the following command is available in the verbatim package.

begin{comment}

Commented code

end{comment}

But is there a simple command like /* code */ in C?

Following the C code paradigm, where one can use the preprocessor directives

#if 0

junk code

#endif

something similar can be done in TeX (and descendants):

iffalse

I don't want this to happen

fi

The commented parts can be easily activated by replacing iffalse with iftrue.

No, but you can define something close:

documentclass{article}

begin{document}

longdef/*#1*/{}



AAA



/* This is a test

    and this is another

*/



BBB

end{document}

Here's a poor man's version of the answer linked by Aditya above. It doesn't require ConTeXt but it does need to be compiled with LuaTeX. With it you can use C style comments: /*comment*/. A potential downside is that it "works" even in a verbatim environment. It works in all situations I can think of.

This input:

Gives this output:

documentclass{article}



usepackage{luacode}



begin{luacode*}



commenting = false

local gsub = string.gsub



local opencomm = "%/%*(.*)"

local closecomm = "(.-)%*%/"



function comment(s)

    if not commenting then

        s = gsub(s,opencomm,

                function(s1)

                commenting = true

                s1 =  gsub(s1,closecomm,function(s2) commenting = false return "" end,1)

                  if commenting then return "" else

                      return comment(s1)

                  end

              end

            )

    else

        s = gsub(s,"(.+)",

                function(s3)

                s3 =  gsub(s,closecomm,function(s4) commenting = false return "" end,1)

                    if commenting then return "%" else

                        return comment(s3)

                    end

                end

                )

    end

    return s

end



luatexbase.add_to_callback('process_input_buffer', comment, 'comment')

end{luacode*}



begin{document}



1 /*HIDDEN*/ 2



1 /*HIDDEN

HIDDEN*/ 2



1/*HIDDEN

HIDDEN

HIDDEN*/2



1 /*HIDDEN 

HIDDEN*/ 2 /*HIDDEN*/ 3



1 /*HIDDEN*/ 2 /*HIDDEN

HIDDEN*/ 3



end{document}

I think the most straightforward way to do this is to use a TeX editor. TeXnicCenter for instance offers to comment and uncomment marked blocks by ctrl+q and ctrl+w. This simply adds a '%' at the respective lines. This further grays out commented section, which is not the case with scripted solutions.

Short: put directlua{-- before the block and a single } after the block when compiling with Lua(La)TeX.

Long: this is a "bug" of LuaTeX turned into a feature, or what make programmers happy. Putting a double hyphen in front of a text in Lua means a single-line comment; however, since TeX strips newlines from Lua code, this appears as a single-line chunk to Lua and so all the chunk gets commented.

Not tested, but I think you could alias that as

newcommand{multlinecomment}[1]{directlua{-- #1}}

and then enclose your comment as in

multlinecomment{

  My multiline

  comment

  with Lorem ipsum.

}