Date: Nov 14, 2012 1:50 AM
Author: Murray Eisenberg
Subject: Re: Is there a way to do comment with just one keystroke at the start as

On Nov 13, 2012, at 12:05 AM, Eric Rasmusen <> wrote:
> The standard way to do comments in Mathematica is like this
> (*Here is a comment*)
> In Latex, a short comment only takes one symbol, at the start of the line:
> %Here is a latex comment
> Is there a way to comment in Mathematica without the closing symbols? is there an any easy way to make a macro to imitate latex comments?

Sorry, but that's the way it is.

Of course you could use Text cells instead of embedding comments inside an Input cell.

That won't work, of course, if you need to insert comments within (too?)-long code in an Input cell. In the latter case, you could try the following:

Comment[blah___] := Null

For example:

Comment["first we do this"]
1 + 1
x + 2

The _three_ underscores in the argument pattern blah___ for Comment is to allow the final usage just shown, with no argument, so as to avoid seeing a literal Comment[] returned from it.

The trouble is that the function Comment also requires a closing bracket. At least that's one less symbol than the two in *) closing an ordinary comment. You could avoid even that by using prefix notation, provided you ensure the argument is a single symbol or a string:

Comment@"first we do this"

Unfortunately, that requires a close-quote, so it's not better than the Comment[=85] construction.

Murray Eisenberg
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2838 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305