[plt-scheme] Student parsing problem

From: Anthony Cowley (acowley at seas.upenn.edu)
Date: Wed Jun 3 13:30:28 EDT 2009

On Wed, Jun 3, 2009 at 1:14 PM, Eli Barzilay<eli at barzilay.org> wrote:
> On Jun  3, John Clements wrote:
>> On Jun 3, 2009, at 8:40 AM, Eli Barzilay wrote:
>> > and it works with multiple expressions too:
>> >
>> >  (define (foo x)
>> >    ;#;#;
>> >    (printf "foo\n")
>> >    (printf "  x = ~s\n" x)
>> >    ...)
>> This is the most frightening idea I've heard today.
> I *seriously* don't see what would be frightening about it.

FWIW, I reflexively looked away from the screen in horror when I saw
that, too. In my case, at least, it's not simply the leading
semicolon, but an unfamiliarity with using #; in such a manner. My
reaction to the ;#;#; combination is a wooks-ian aversion to opaque
notation whose far-reaching semantics are not immediately obvious,
"Oh, this is a commented out notation that, if uncommented, would
comment out the next two (count 'em!) S-expressions!"

My real aversion was to the stacking of the #;, commenting them out is
just the kicker. I'm now going to mentally prepare myself for the day
when I come across code with #;#;#;;#;;#; in front of some
vertically-long expressions.


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