Re: COMMENT: LAST CALL comment

On Wed, 4 Jun 1997, Ross Patterson wrote:

> David W. Morris" <dwm@xpasc.com> writes:
> That's an interesting definition of "no surprises", unless you mean that
> a quoted-string is always treated identically, regardless of context.

Yup, for something as fundamental to modern programming languages as
quoted strings, there ought to be a real good reason for changing the
behavior.

> I'd count processing of characters within a supposedly opaque value as
> quite surprising.

But my point is that the quoted string IS NOT the value which is opaque,
it becomes the opaque value after resolving quoted pairs.

> Much of the world is neither C nor Unix, and it certainly is arguable
> whether many HTTP implementers had existing RFC822-compliant lexical
> analyzers to steal the quoted-string support from.  Given that HTTP 1.0
> had an extremely simple quoted-string, I'll bet that any HTTP
> implementations that incorrectly accept quoted-pairs can be traced to
> a single code source.

Not me, I crib no code, and I can almost guarantee I've written parsers
which handle quoted pairs in the very generic C sense. Sloppy perhaps, but
no more so than defining a quoted string which does't at least allow for
escaping " and \ characters. A parser which simply treats the single
character following \ as a simple character is much easier to code than
a bunch of special cases. Adding to that translation for a few cases is
still easy. The parser eats two characters and outputs one. But at this
point I'm not arguing for or against anything except the quoted pair
concept. Not \n and not 0xa parsing.

David Morris

Received on Wednesday, 4 June 1997 15:01:18 UTC