Dear Scheme implementors, users, et.al., I've got a few questions to all of you (and to members of the committee that has standardized R6RS in particular). If I follow the discussions found on r6rs.org regarding pattern matching, then, if I understood correctly, the stance is that the committee wanted to align compile-time pattern matching (syntax-case, syntax-rules) with a possible run-time pattern matching in the future, as well as support structures/records and other user-defined types (for extensibility).
In particular, the Bigloo's match-case run-time pattern matching has been discussed, but not selected by the committee (or even fully understood, AFAICS). My understanding is that one of the reasons was explicit pattern variable decorators and missing ellipsis. So the committee proceeded with syntax-case, and disregarded the run-time pattern matching entirely. I don't see any of it in the R6RS standard, not even as a SRFI (although there are a few proposals that could be subsumed by it, e.g., case-lambda, let-with-multiple-values), although somebody from srfi.schemers.org did say he worked on it. While I have no personal stake in this, I am, as a user, in fact quite disappointed in not seeing full-scale pattern matching applied in Scheme (and supported by standards), in the manner that other languages such as MLs and Haskell so fervently implement. Hence my question: what is the state of pattern matching in Scheme? Are there ideas to move this forward, or are we, the poor users, left to live with incompatible pattern matching interfaces and implementations? Just to mention a few: Bigloo's match-case, PLT/Racket match.ss variants and many more. Kind regards, Pjotr Kourzanov _______________________________________________ r6rs-discuss mailing list r6rs-discuss@lists.r6rs.org http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
