On Sat, Sep 19, 2009 at 11:34:57AM +0100, Alaric Snell-Pym wrote: > > If we want to drop a feature that basic, then surely we should > > first deprecate it and move it to a library (R7) and second > > make the library optional (R8) so that its eventual absence > > does not come as a shock to users. > > I think that's basically the long-term of what John's suggesting, by > removing it from the Thing One core; the only point of contention here > is whether it's an *optional* library or not...
I agree this is the important point of the discussion. > > Scheme has always had as one of its strengths the fact that you > > can use it to express many different paradigms of programming, > > and I think that taking steps to *reduce* its value for one or > > more paradigms is a mistake. > > The thing is, the sheer possibility of string-set! makes other string > operations consume more time/space resources, which reduces their > value. It's a choice between two costs which have different effects > for different situations. > > I'd like to see: > > 1) Some implementations with immutable strings > 2) Some implementations with mutable strings > 3) Some implementations that give you both, where all string > operations that don't mutate work seamlessly on both, with explicit > make-mutable-string and make-immutable-string operations, and a > parameter that selects whether newly created strings are one or the > other (from read, *->string, etc). Agreed. It makes a whole lot of sense for ASCII-only implementations (which should be allowed by Thing One, I believe ~everyone agrees on) to supply a string-set!. Why wouldn't they, it's a cheap operation in such an environment. Also, ASCII-only schemes would probably be the more minimalistic ones, which likely are used in systems programming, where string-set! can still be quite a useful operation. Cheers, Peter -- http://sjamaan.ath.cx -- "The process of preparing programs for a digital computer is especially attractive, not only because it can be economically and scientifically rewarding, but also because it can be an aesthetic experience much like composing poetry or music." -- Donald Knuth
pgp2aClueSWKI.pgp
Description: PGP signature
_______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
