Re: [Slib-discuss] Several (minor) glitches in testing format feature.

[Aubrey Jaffer]

 | From: Kris De Volder <address@hidden>
 | Date: Sun, 14 Dec 2008 15:20:40 -0800
 | 
 | On Sat, 2008-12-13 at 22:18 -0500, Aubrey Jaffer wrote:Not as I read R4RS:
 | > 
 | > ...
 | 
 | I agree your reading, where the "encouraged but not required"
 | doesn't apply to this section, makes more sense. So a fixnum
 | implementation of / is then required to return exact results when
 | possible and only should signal an error for things like (/ 3 2)
 | which don't have an exact integer result.
 | 
 | If this is the right interpretation, perhaps another test or two
 | should be added to r4rstest.scm. (e.g (/ 6 2) => 3)

Done.

 | >  | 2) test in formattst.scm that test flonums without checking
 | >  | they are supported by the implementation:
 | >  | 
 | >  | (load "formatst.scm")
 | >  | ...
 | >  | error at line: 82 col: 1 in
 | >  | file:/home/kdvolder/workspaces/kscheme/ca.kscheme/bin/slib/formatst.scm
 | >  |     (test '("~a" -1.2) "-1.2")
 | >  | 
 | >  | I propose to change this line to:
 | >  |     (if format:floats (test '("~a" -1.2) "-1.2"))
 | > 
 | > But the implementation will still choke reading -1.2.  I think it
 | > needs to be:
 | > 
 | >   (if format:floats (test '("~a" (string->number "-1.2")) "-1.2"))
 | 
 | Even better. My reader "accidentally" parses -1.2 as something (not
 | a number) but this is really idiosyncratic.

There are many more floating-point literals in "formatst.scm" which
are syntax errors for an exacts-only implementation.  "formatst.scm"
is for testing "format.scm", not for testing any sort of
implementation compliance.

Note that running "formatst.scm" on an exacts-only implementation
yields significantly less test coverage than running "formatst.scm" in
an implementation with inexacts.  If someone sends me a "formatst.scm"
so wrapped, I will update SLIB; but I am not interested in doing this
gilding myself.

 | >  | 3) version discrepancy with sc4opt.scm?
 | >  | ...
 | 
 | Thanks for clearing that up. 
 | 
 | I'll summarize for the list: (correct me if I'm reading this wrong) 
 | 
 |  - The fact that the sc4 tests aren't run by default is so that the
 | test can be used for testing IEEE scheme compliant implementations.
 | 
 |  - To be slib compatible however, an implementation must be fully
 | R4RS compliant and it *must* pass the sc4 tests.

I agree.