I completely agree with what you said here, John. We both took a good look, but you squinted with your right eye, and I with my left. :-) Either point of view is correct; the two together yield depth perception. Yay!
> On May 3, 2019, at 4:21 PM, John Rose <john.r.r...@oracle.com> wrote: > > On Apr 29, 2019, at 8:48 AM, Guy Steele <guy.ste...@oracle.com> wrote: >> >>> On Apr 28, 2019, at 4:32 PM, Brian Goetz <brian.go...@oracle.com> wrote: >>> >>> . . . >>> Looking ahead to the next round, we can build on this. In the first round, >>> we mistakenly thought that there was something that could reasonably be >>> called a “raw” string, but this notion is a fantasy; no string literal is >>> so raw that it can’t recognize its closing delimiter. So “rawness” is >>> really only a matter of degree. >> >> This is _almost_ true. If a string is truly raw (that is, it can contain >> _anything_), then one absolutely cannot depend on recognizing the closing >> delimiter by examining what might be the raw content. >> >> Put another way: one cannot determine how long the raw content is by >> examining it. That’s a solid principle. > > I'm going to be nit-picky here and refer to my earlier > mentions of the paradigm of strong quoting, which > at its heart simply means you have an infinite set of > delimiters to choose from, when wrapping a payload > into a literal syntax. > > Adding a numeral to the open quote means that there > are now an unbounded set of open quotes, so it is an > instance of strong quoting. Another instance of strong > quoting adds nonces, and yet another just lengthens > the quote pattern until it doesn't occur (anywhere) in > the raw string payload. > > The numeric prefix convention is different from other > kinds of strong quoting conventions, in that the end-quote > can be a substring of the payload. Actually, the end-quote > is most naturally the empty string, which is a substring > of every string. > > The numeric prefix convention and other strong-quote > conventions all share a common property: The convention > as a whole is universal for arbitrary payloads, but for > any given payload there are quotes which work and others > that don't work. In the case of the numeric prefix > convention, once you choose an open-quote (with > numeral) you are limited to payloads of that length. > That's not quite a "raw string" any more, since it's > suitable only for a fixed-sized character field. > Likewise, once you choose a particular nonce-based > or patterned quote (e.g., seven double-quotes), > payloads containing the corresponding end-quote > as a substring are no longer suitable. > > Once you pick a particular payload string, the next > question is whether you can embed that particular > string into your program without inserting escape > sequences. Only with a strong quote scheme of > some sort is this possible. But, with any of several > strong quote schemes, it is possible to dispense > with escapes for any given string; it is not a fantasy. > > — John
