Subject: [Megaco] Question about VALUE definition in ABNF?

From: [email-masked]
Date: Tue, 7 Jan 2003 15:35:10 +0900

Hi, All.

I think the VALUE defition is too general.
So When scanning, It is difficult to get the VALUE as a token.
Because It looks like contain kind of dilimiters (e.g. "/", "-").

for example) when scanning "ABC/123"(this is not quoted string),  
the scanner may get the tokens following way.
token - ABC : Name
token - / : SLASH
token - 123 : decimal
the scanner may not get the tokens following way
token-ABC/123 : Value

As a result of above issue, When implementing, Grammar may lose the general
syntax.
For example)
In case of alternativeValue,
In ABNF : alternativeValue = VALUE, it is very simple.
but in real implementation, we should consider all possible VALUE forms:
alternativieValue : Name Slash Integer
                         | Integer Slash Name
                         | Name Minus Name
                         | Name Minus Integer
                         | ....
                         | ....
                         | ....
(where Name, Slash, Integer, Minus are tokens returned by the scanner)

It means there are chances to redfine VALUE on the fine granuality.
we may get rid of kinds of delimiter(e.g. /, -) from SafeChar or we can
redefine VALUE definition with giving constraints.
for example)

please give me your opinions. 
TIS.