Numeric methods again
Magnus Lie Hetland
mlh at idi.ntnu.no
Wed Jul 25 14:56:45 EDT 2001
"Martin von Loewis" <loewis at informatik.hu-berlin.de> wrote in message
news:j4ofq8hp0w.fsf at informatik.hu-berlin.de...
> "Magnus Lie Hetland" <mlh at idi.ntnu.no> writes:
>
> > in front of the reference dot... For a simple parser
> > it might be difficult to know whether 5. was a float
> > or the beginning of a reference, but with a bit of
> > lookahead that can't be too hard?
>
> If you want to allow "5.foo", you certainly also need to allow
> "5. foo", as you can also write "a. foo". So it requires arbitrary
> look-ahead.
I'm sure you didn't think I meant that "5. foo" should be outlawed?
I'm just surprised that it should be _required_.
And it would only require one token lookahead, as long as the scanner
compresses the whitespace... But, as I said, that's not the issue.
> > Can a number ever be directly followed by an identifier?
>
> Yes, certainly: "5.e17" could be either 5*10**17, or the e17 attribute
> of 5.
Right. I guess that's the problem, then. But since all the methods of
numeric constants begin with an underscore, that really ought not
to be a problem... Right?
> Regards,
> Martin
- Magnus, still wondering what the _real_ problem is...
--
Magnus Lie Hetland http://www.hetland.org
"Reality is that which, when you stop believing in
it, doesn't go away." -- Philip K. Dick
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