At 16:02 02/06/04 +0100, Keith Wansbrough wrote:
I think SimonM's suggestion of an RFC2822-like syntax is reasonable, but it
[my suggestion, not SimonM's!]
Oops, sorry!
would probably be better to not simply cite RFC2822, since some
I agree, we should give an explicit definition. I don't think it's likely to be very complicated.
Indeed.
complications might arise. An alternative might be XML, which would be a more "modern" choice.
Ugh! No! Please! No! No reason to do this - remember, this file is written by Angela Author, who has just written a Haskell module or two, and doesn't have a handly XML structured editor to hand. She just wants to fire up her text editor and write three lines.
I wasn't strenuously arguing for that, just noting a possible alternative.
Some nits to look out for with RFC2822 format are: + Internationalization and non-ASCII characters
We should specify either Latin-1 or Unicode/UTF-8. The latter, I guess.
Yes, Unicode would seem appropriate, and UTF-8 is a popular encoding.
+ Case (in)sensitivity of header field names
Insensitive would follow the Principle of Least Surprise.
I think so.
+ No support for structured information (text string values only). + No facility for grouping information + Comments in some header field values
I was imagining that the text string would almost always be a Haskell value, using the Haskell lexer and a Haskell-related parser. This would give us comments and structure.
I wasn't aware that there was a comment convention for Haskell *values*, just Haskell code. I guess that's what you meant.
+ Extensibility model
Yes, this should be specified. The document already implies "ignore headers you don't understand", which is good.
The minimum requirement seems to be a combination of: (a) ignore what you don't understand, unless (b) the document says you *must* understand certain headers or fail entirely.
Try this, using the Haskell Report grammar syntax, and Section 2.2 of the Haskell Report for the definitions of <lexeme>, <newline>, and <whitespace>:
<description> ::= { <descline> }
<descline> ::= <fieldname> : { <lexeme> | <foldedwhitespace> } <newline>
<foldedwhitespace> ::= <whitespace> | <newline> <whitespace>
with the proviso that any <newline> in <foldedwhitespace> has no semantic significance.
Alternatively, we could provide Haskell code as specification here.
Sure, that bit's easy enough. But there's devil in them there details. Not too much, though. #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact