IPP> Re: Use of "-" for range in ABNF: confusion with "-" in rule names?

IPP> Re: Use of "-" for range in ABNF: confusion with "-" in rule names?

IPP> Re: Use of "-" for range in ABNF: confusion with "-" in rule names?

Keith Moore moore at cs.utk.edu
Thu Apr 17 16:54:01 EDT 1997


> I happen to like ".." a lot, since it is natural and has been used in ASN.1
> and some programming languages.  So picking something new for ranges
> will confuse a lot of people who will be seeing ABNF for the first time.
> 
> I'm also concerned that changing to "-" for ranges may create confusion 
> with "-" in rule names (IPP uses rule names for attribute names and 
> attribute value names)


It's not a huge deal as far as coding is concerned -- the immediately
preceding context suffices to distinguish "-" in identifiers from "-"
in ranges -- but I still prefer either ".." or ":" to "-".
Recognizing ".." is no more difficult than distinguishing the two
meanings of "-".


And while I can't think of many other meanings of ".." than to
indicate some sort of range. "-", on the other hand, is quite
overloaded.


Keith



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