> 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.
But there are other ways of determining how long it is. All have this property
in common: you have to know how long the content is before you begin to scan
it. And this leads to an obvious solution: you need a count of bytes up front.
The design currently under consideration can easily accommodate this, now or in
the future: a raw string is an opening delimiter, then a byte count (say,
expressed as a decimal integer), then a LineTerminator , then as many bytes as
the count indicated, then a LineTerminator, then a closing delimiter (the last
two are not really needed, but they look nice, satisfy user expectations, and
provide some redundancy to help make sure the byte count was correct).
Examples:
String PrintableAscii = “””95
!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
“””; // no need to worry about that embedded backslash
String LotsaQuotes = “””50
“””””””””"“””””””””"“””””””””"“””””””””"“”””””””””
“””; // the payload cannot be confused with the closing delimiter
String LineNoise = “””16
”””; // I pasted in ^H^I^J^K^L^M^N^O^P^Q^R^S^T^U^V^W
here—not sure how it will render in your mail reader
The syntax could be further adjusted in arbitrary ways for added clarity: for
example
String PrintableAscii = “””RAW DATA (95 bytes):
!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
“””;
Presumably an IDE could help you make sure the byte count is correct.
—Guy
