Scheme language standardization process
On Sun, Jul 1, 2012 at 10:19 PM, Marc Feeley <feeley@x> wrote: > The R5RS has the following sequence to sequence conversion procedures: > > list->string, and string->list > list->vector, and vector->list > > The R7RS is adding bytevector sequences, but it does not add the conversion procedures: > > list->bytevector, and bytevector->list > > What is the rationale for this inconsistency? > > Moreover, the R7RS is adding only the first set of these conversion procedures: > > vector->string, and string->vector > bytevector->string, and string->bytevector (not in R7RS) > vector->bytevector, and bytevector->vector (not in R7RS) Actually, we have the second, it's just named utf8->string and string->utf8 to emphasize the encoding used to convert to and from a bytevector. > yet for consistency they should be added. Why is the conversion between vectors and strings priviledged by the standard? > > Personnaly, I think these conversion procedures should not be added to the standard because for consistency, any sequence types added by an implementation of Scheme (or future standard) would require N^2 conversion procedures. Only the conversions to and from lists should be specified, and a "sufficiently intelligent compiler" can handle compositions such as > > (list->string (vector->list v)) > > like the proposed (vector->string v), if performance is an issue. Bytevectors are a special-purpose data-structure, for which conversions from general containers are not necessarily possible (although this is also true of strings). I agree we don't need all O(n^2) procedures. Ticket #433 filed to consider the bytevector to list (or vector) case. -- Alex _______________________________________________ Scheme-reports mailing list Scheme-reports@x http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports