Re: [Nasm-devel] git master branch disallows question mark in identifiers

[Ruslan K. <b7....@gm...>]

On Sat, 15 Dec 2018 at 23:07, C. Masloch <pu...@38...> wrote:
>
> On at 2018-12-14 01:38 -0800, H. Peter Anvin wrote:
> > On 12/4/18 4:02 AM, C. Masloch wrote:
> >>
> >> Oh yeah, you're right. Yes, it'd definitely be useful to support both
> >> the operator and question mark in identifiers.
> >>
> >
> > OK, the most logical way to deal with this seems to be to treat ? as a
> > *keyword*, rather than a *character*. In other words, since ? is
> > legitimate in identifiers, it is also a legitimate keyword. Just like
> > any other keyword, it has to be separated from other keywords by
> > whitespace or other non-identifier characters.
>
> Thanks, I tested building from git 33b5d21fbdc9 and it seems to handle everything the way it should, ie still allowing me to use the question mark in define names.
>
> >> (Side question: Would it be possible to "evaluate" expressions with
> >> strings as result? Eg << db _FAT16 ? "FAT16" : "FAT12" >>. Currently I
> >> use << db "FAT1",'2'+4*!!_FAT16 >>
> >> https://bitbucket.org/ecm/ldosboot/src/b469e243526d4fbdfe79d6ef4ef677ff2372eb19/boot.asm#lines-490
> >> , which only uses a string that fits as a numeric constant in a byte.)
> >
> > I'm afraid not, although
> >
> >       db "FAT1", _FAT16 ? '6' : '2'
> >
> > ... does work.
> >
> > This is because in NASM, strings used in expressions are always
> > converted to numbers. This isn't something we can realistically change
> > without who knows what breakage.
>
> Yeah, figures.
>
> > Now, since NASM does internal 64-bit arithmetic strings converted to
> > numbers can be up to 8 characters long, but since there is no 5-byte
> > object you can't trivially use it in the way you'd expect.
> >
> > Now, if you had an 8-byte field you could indeed do:
> >
> >       dq _FAT16 ? "FAT16" : "FAT12"
> >
> > ... and you'd get a 5-character string with 3 bytes of zero padding.
>
>
> A side question: Your mails never seem to show up in https://sourceforge.net/p/nasm/mailman/nasm-devel/ -- what's up with that?

FWIW, it seems Peter's mails are not delivered to the mailing list at
all. At least to me, from my inbox POV, this whole thread looks like a
thread of a single author. Only quotations reveal Peter.

>
> Regards,
> ecm
>
>
>
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