Very well explained! From: Per Bothner <[email protected]> Subject: Re: [r6rs-discuss] strange escape sequence in string literals Date: Thu, 18 Nov 2010 13:46:45 -0800
> On 11/18/2010 12:56 PM, Shiro Kawai wrote: >> From: Andy Wingo<[email protected]> >> Subject: Re: [r6rs-discuss] strange escape sequence in string literals >> Date: Thu, 18 Nov 2010 21:29:18 +0100 >> >>> I wonder though, what is the purpose of allowing intraline whitespace >>> before the line ending? >> >> I don't remember if there was any discussion, but I imagine >> that it might be an annoyance if accidental whitespace between >> the backslash and the line ending changes the meaning. >> (I was bitten with it in dreadful C macro definitions...) > > A Scheme source file is a *text* file, rather than a binary file. > The meaning of a text file should (by definition) be independent > of the line-ending convention used. IMO the meaning of a text file > should also be independent of trailing whitespace: Otherwise you > will not be able to "store" a text file in a fixed-line-length file, > as in a deck of cards (some of us remember using them) or fixed-length > "record"-based representations, as used to be common on mainframes. > > Punch cards and fixed-length records are (hopefully) only of > historical interest, but I think it is still a bad idea for a > file format to place significance on the amount of trailing whitespace, > because most text editors and IDEs don't show them. > > What about trailing whitespace in string literals? This is related > to the issue of what if there is a CR-NL pair in a string literal. > So I think the right think to do is for a lexer (including a Scheme > reader) to normalize line endings: strip of trailing whitespace, > and convert CR-NL to NL. > -- > --Per Bothner > [email protected] http://per.bothner.com/ > > _______________________________________________ > r6rs-discuss mailing list > [email protected] > http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
