Scheme language standardization process
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 11/20/2012 02:47 PM, John Cowan wrote: > Mark H Weaver scripsit: >> What I want, indeed what I *require*, is the ability to memoize >> procedures without having to worry that my code might produce the >> wrong answers on some future implementation of R7RS. > 1) So use a memoization comparison function that handles NaN, > negative zero, and the infinities specially. > 2) You can't be sure that an R7RS implementation will provide > these anyway. Let's think about these two statements in combination with one another. First: is it the case that an implementation which does not provide NaN and -0.0 can be a correct implementation of R7RS? If so, is there a standard way for portable code to discover whether the hosting implementation does or does not provide them without invoking an error? Because that's important. Here is why. Assume someone is writing code in an implementation which does not provide NaN. How would they produce code which handles NaN, -0.0, etc, specially but does not invoke a syntax error on their own nor any other implementation? >> Therefore, it appears likely that I will not be able to use >> R7RS. > So be it. Uh, that's kind of a "wrong answer" on this level. It is the goal of this process to produce something that's generally usable, right? Bear -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJQsCk5AAoJEAOzWkqOibfNFJsH/A/H2vcpDF7wNtp1qsxSCubW 7zmv41C7TCt44XACYevz3EZGoIORdxwEueNB5z1wktd+uX4sdEapuFwusfSpi7Xu Hv6fWb6gYjnyXuVORF2AOCu9KNMDT5t+gjqd4id8OciwOqKn2WOHU/5Er42ou4iz GM8mdWHQ2YHcCLUjU4aoS/8N4xbEDo5bM4vtN2JcnR4Tv1MThD6mqj3CBLok6ii2 0dtfHMJmFOlUhruh9fiOTmWI/syvdiO4RTtXAZnJXMWyV6nHO+4MPtSXU08zchfr eqgZHgzNFdB3bTTbvRwNUg3gH0UwS+jRSVdVhc01d3oUo2tUo9J3ofBQ9ZolxZA= =t7mO -----END PGP SIGNATURE----- _______________________________________________ Scheme-reports mailing list Scheme-reports@x http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports