Re: Is there a way to do large block of source code comments

[Adam Beneschan <adambeneschan@gmail.com>]

On Tuesday, September 2, 2014 5:07:56 PM UTC-7, robin....@gmail.com wrote:

> > No, this was explicitly omitted. See the Ada-83 Rationale 2.1: "Single comments
> > that are larger than one line are not provided. Such comments would require a
> > closing comment delimiter and this would again raise the dangers associated with
> > the (unintentional) omission of the closing delimiter: entire sections of a
> > program could be ignored by the compiler without the programmer realizing it, so
> > that the program would not mean what he thinks. Long comments can be written as
> > a succession of single line comments, thus combining elegance with safety."

> When a block of code is to be omitted (temporarily or semi-permanently)
> it's convenient to have something like /* and */ as comment markers.
> 
> It's also convenient to have comment markers for long blocks of comments.
> 
> Live parsing editors are useful tools, because they highlight
> code segments (including comments).
> 
> The above quotation is mere hype, like the author's justification for omitting
> exponentiation in Pascal, somehow more convenient to use log and exp instead!

No, the quotation was not hype.  The problems caused by missing end-comment delimiters were real.

If you're thinking that this shouldn't be a problem because of "live parsing editors", you're right--in 2014.  But the document that you claim contains "mere hype" is the Ada 83 Rationale, which came out in (drum roll) 1983.  (Or perhaps a bit later, but the rationales weren't rationalizations created after the fact.)  Ada's development started several years before that.  The IBM PC came out in 1981, and it would have been some time before GUI editors were available (Eclipse was first released on 2001).  Before the PC, the video systems that programmers had available for developing programs would have been monochrome terminals with one font (but perhaps with some bold-face and reverse-video capabilities) and no graphics.  The screen-oriented editors I remember using for Pascal programming did not have any awareness of program syntax, like today's tools do.

Also, the same "live parsing editors" that are capable of coloring comments so that you can see that you've forgotten the end delimiter, are also capable of doing block comments.  Eclipse has a command to do this in Java programs, and it does so by adding // to the beginning of each selected line, not by using /* and */ (which in Java programs is normally only used for "javadoc" comments, comments that describe the the functionality and parameters of methods, that have a special format that can get translated to HTML).

                               -- Adam