Aubrey Jaffer wrote:
> Here is my "No" vote:
>
> -=-=-=-=-
>
> There are many flawed aspects of R5.97RS, which time does not permit
> me to cover. I will describe three.
>
> Macros
>
> ...
>
> The effect of adding macros to Scheme has been the proliferation of
> mutually incomprehensible language dialects. We have seen the growth
> of "convenience" macros like WHENNOT and UNLESS, use of macros as a
> substitute for compiler optimization, and use of macros to avoid using
> symbols as tokens. None of these uses increases the *expressive power*
> of the language.
>
>
"On the Expressive Power of Programming Languages", macro is the way to
compose a language that only has a small number of rules to be able to
express more.
> In a reusable software world, the use of incompatible dialects is
> detrimental; it is only through documenting, publishing, and
> deliberating, say in a SRFI, that new forms should be adopted into
> that "very small number of rules for forming expressions".
>
> Arrays
>
> Computations have been organized into multidimensional arrays for over
> 200 years. Applications for multi-dimensional arrays are widespread
> and continue to arise. Computer graphics and imaging, whether vector
> or raster based, use arrays. A general-purpose computer language
> without multidimensional arrays is an oxymoron.
>
> Although multidimensional arrays are the subject of SRFI-25, SRFI-47,
> SRFI-58, and SRFI-63, and portably supported by SLIB, search of
> http://www.r6rs.org/r6rs-editors/ finds nothing to indicate that the
> editors ever considered their inclusion in R6RS.
>
> Can R5.97R Scheme be extended to support SRFI-63 arrays?
>
>
One story: an unusable version of SRFI-63 was once put in PLT Scheme for
about 1 year, yet not any complain was heard. If now there is a vote for
SRFI-63, I will definitely vote for no.
> Libraries
>
> ...
Yes, R5.97RS's module system only supports internal linking. But
external linking can be provided in a portable fashion on top it (using
macros).
> Conclusion
>
> The framework to extend R4RS and R5RS (through redefinition) made it
> possible to provide those features that Scheme lacked in a portable
> and modular fashion. R5.97RS not only lacks the multidimensional
> arrays essential to my work, it has removed the means for remediation
> of its deficiencies.
>
>
Chongkai
Received on Tue Aug 14 2007 - 01:18:31 UTC