* libguile/numbers.c (scm_euclidean_quo_and_rem, scm_euclidean_quotient,
scm_euclidean_remainder, scm_centered_quo_and_rem,
scm_centered_quotient, scm_centered_remainder): New extensible
procedures `euclidean/', `euclidean-quotient', `euclidean-remainder',
`centered/', `centered-quotient', `centered-remainder'.
* libguile/numbers.h: Add function prototypes.
* module/rnrs/base.scm: Remove incorrect stub implementations of `div',
`mod', `div-and-mod', `div0', `mod0', and `div0-and-mod0'. Instead do
renaming imports of `euclidean-quotient', `euclidean-remainder',
`euclidean/', `centered-quotient', `centered-remainder', and
`centered/', which are equivalent to the R6RS operators.
* module/rnrs/arithmetic/fixnums.scm (fxdiv, fxmod, fxdiv-and-mod,
fxdiv0, fxmod0, fxdiv0-and-mod0): Remove redundant checks for division
by zero and unnecessary complexity.
(fx+/carry): Remove unneeded calls to `inexact->exact'.
* module/rnrs/arithmetic/flonums.scm (fldiv, flmod, fldiv-and-mod,
fldiv0, flmod0, fldiv0-and-mod0): Remove redundant checks for division
by zero and unnecessary complexity. Remove unneeded calls to
`inexact->exact' and `exact->inexact'
* test-suite/tests/numbers.test: (test-eqv?): New internal predicate for
comparing numerical outputs with expected values.
Add extensive test code for `euclidean/', `euclidean-quotient',
`euclidean-remainder', `centered/', `centered-quotient',
`centered-remainder'.
* test-suite/tests/r6rs-arithmetic-fixnums.test: Fix some broken test
cases, and remove `unresolved' test markers for `fxdiv', `fxmod',
`fxdiv-and-mod', `fxdiv0', `fxmod0', and `fxdiv0-and-mod0'.
* test-suite/tests/r6rs-arithmetic-flonums.test: Remove `unresolved'
test markers for `fldiv', `flmod', `fldiv-and-mod', `fldiv0',
`flmod0', and `fldiv0-and-mod0'.
* doc/ref/api-data.texi (Arithmetic): Document `euclidean/',
`euclidean-quotient', `euclidean-remainder', `centered/',
`centered-quotient', and `centered-remainder'.
(Operations on Integer Values): Add cross-references to `euclidean/'
et al, from `quotient', `remainder', and `modulo'.
* doc/ref/r6rs.texi (rnrs base): Improve documentation for `div', `mod',
`div-and-mod', `div0', `mod0', and `div0-and-mod0'. Add
cross-references to `euclidean/' et al.
* NEWS: Add NEWS entry.
* module/rnrs/arithmetic/6/fixnums.scm: Fix missing imports;
(fixnum-width, greatest-fixnum, least-fixnum): Redefine these as
zero-argument procedures; Fix argument mismatches in several functions.
* test-suite/Makefile.am: Add tests/r6rs-arithmetic-fixnums.test to
SCM_TESTS.
* test-suite/tests/r6rs-arithmetic-fixnums.test: New file.
