On Tue, Mar 13, 2012 at 2:02 PM, John Cowan <[email protected]> wrote: > Andrew Robbins scripsit: > >> In terms of transmission, the (inline hex escape) lexical space of >> R6RS is sufficient to encompass most of the value space of (vertical >> bar) identifiers, with the added bonus of being able to be transmitted >> to interpreters and compilers via 8-bit unsafe channels and 7-bit >> encoded ASCII text files. > > Everything except ||, the result of (string->symbol ""). > >> Neither (vertical bar) nor Unicode identifiers (also added in R6RS) >> can make this claim. > > Vertical bar as defined in draft 6 allows inline hex escapes within the > bars, so it allows everything that inline hex escapes do. > >> Why would we add 1114111 redundancies to Scheme identifier lexical >> space when the only addition to the value space is ||? > > Vertical bars allow mixed-case identifiers in a case-folding context to > be readable. |Foo| is much more readable than \x46;oo, and |FOO| is > infinitely more readable than \x46;\x4F;\x4F;. This is the example that > convinced me of the virtues of |...|.
I had already recommended before to use \x46; and \|...| as the single and multiple escape mechanism. That kills two birds with one character leaving |...| open. I think it's also not overly antagonistic to Gambit's six notation since neither an initial "|" nor "xNN;" would be meaningful in six. I'll add this option to the ballot. -- Alex _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
