Shiro Kawai scripsit: > This is a somewhat old issue, but I wonder how '|' symbol escapes > ended up excluding '|' and '\' inside it. Does it intend a room for > future extension that vertical bar and backslashes can be included in > '|' symbol escapes by escaping them with '\', as in CL? I searched > tickets in the WG1 trac site but couldn't find the discussions on it > except ticket #16.
I am not sure I understand this. \-escaping *is* allowed within |-escaping, so |(\x3BB;)| is the identifier "parenthesized lambda". Indeed, there is a ticket pending to disallow \-escaping by itself and allow it only within |-escaping. That would allow \ to be an ordinary identifier character. > - CL also has '|'-escapes but they don't delimit symbols, so > |abc|def|ghi| is read as a single symbol abcDEFghi. R7RS doesn't > explicitly say '|' delimits the symbol, but also doesn't seem to > allow |abc|def syntax according to 7.1.1. I'm fine with either way, > but was it a conscious decision? It was a conscious decision to make vertical bars delimit the symbol, in the same way that quotes delimit a string. The wording of 2.1 is meant to imply this: a symbol can begin with |, contain arbitrary characters or inline hex escapes, and end with |. -- Well, I have news for our current leaders John Cowan and the leaders of tomorrow: the Bill of [email protected] Rights is not a frivolous luxury, in force http://www.ccil.org/~cowan only during times of peace and prosperity. We don't just push it to the side when the going gets tough. --Molly Ivins _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
