Re: iSCSI: Re: range separator

[Bill Studenmund <wrstuden@wasabisystems.com>]

On Thu, 21 Mar 2002, Luben Tuikov wrote:

> Eddy Quicksall wrote:
> >
> > That would be ok for something like an expression parser but our parser
> > should be very simple minded and it is better if it is not context
> > sensitive. It is the same idea as "don't use two characters".
>
> Context: are you parsing ``MaxConnections=3''
> or ``3''. You see, your parser is already
> context sensitive.
>
> As iSCSI grows, undoubtedly each parameter/variable
> will be handled by it's own string value parser,

Well, there probably won't be that many parsers. One set-of-numbers parser
can be used for all the number-expecting cases.

> and _THEN_ you'd abstractize into
>  integer value, or
>  string value, or
>  range.
>
> Note, that a range is
> a string (we know this already) of
> <integer><range symbol><integer> to use context
> free grammar (stripped down version :-).
>
> Philosophically, the debate is whether to use
> 1 character or many.
>
> I vote for just a single char. Anywhich one.

Agreed.

> Using a different character to tell us that
> this string denotes a range is not quite a
> solution here. E.g.:
>
> MaxConnections=3<your range symbol here>10
>
> So the Target will know that it is a range,
> but it doesn't matter... it will have to check
> the context anyway...

Won't the parser already have to have figured out the context anyway? We
have to know if the key is: 1) valid, and 2) appropriate for this phase
already, don't we? After figuring that out, is it hard to know if we
expect a string or one or more numbers?

Take care,

Bill