2006/12/6, Marius Vollmer [EMAIL PROTECTED]:
Kevin Ryde [EMAIL PROTECTED] writes:
The only case I can think of where a common zero may not be good is
with matrices, where (* 0 matrix) = matrix could preserve the
dimensions of the input matrix in the output matrix.
I would have to dig for
2006/12/5, SZAVAI Gyula [EMAIL PROTECTED]:
Kevin Ryde wrote:
Mikael Djurfeldt [EMAIL PROTECTED] writes:
(Not entirely sure that the common zero is a good idea, but I tend
to think so.)
I suppose it's a question of whether * should do that, or leave it
up to the application.
I think
2006/12/4, Kevin Ryde [EMAIL PROTECTED]:
While nosing around nearby stuff I noticed
(* 0 1.0) = 0
(* 0 1+1i) = 0
but
(* 1.0 0) = 0.0
(* 1+1i 0) = 0.0
which seems a bit inconsistent.
Indeed.
R5RS Exactness reads like either
exact or inexact is permitted,
Mikael Djurfeldt [EMAIL PROTECTED] writes:
Good idea.
I made the change.
Because of paragraph 6.2.2, a program cannot expect to get
the result 0.0, and it seems like a strength of the implementation to
provide the additional piece of information that the result is indeed
*exactly* 0.
If
While nosing around nearby stuff I noticed
(* 0 1.0) = 0
(* 0 1+1i) = 0
but
(* 1.0 0) = 0.0
(* 1+1i 0) = 0.0
which seems a bit inconsistent. R5RS Exactness reads like either
exact or inexact is permitted, but I imagine it ought to be the same
whichever way
SZAVAI Gyula [EMAIL PROTECTED] writes:
(use-modules (oop goops))
(define-class c ())
(define-method (* a (b c)) #t)
(* 0 (make c))
== 0
Thanks, that's a bug.
- switch (xx)
- {
-case 0: return x; break;
-case 1: return y; break;
- }
-
Though that's
2006/12/1, Kevin Ryde [EMAIL PROTECTED]:
SZAVAI Gyula [EMAIL PROTECTED] writes:
(use-modules (oop goops))
(define-class c ())
(define-method (* a (b c)) #t)
(* 0 (make c))
== 0
Thanks, that's a bug.
Are you sure?
If you want to use an operator which is common for numbers and c:s,
why
Mikael Djurfeldt [EMAIL PROTECTED] writes:
If you want to use an operator which is common for numbers and c:s,
why don't you want to use a common zero? If you don't, the behavior
of the operator will be inconsistent.
For multiply by 0, I can sort of think of cases when the return type
guile-1.8-20061126
(use-modules (oop goops))
(define-class c ())
(define-method (* a (b c)) #t)
(* 0 (make c))
== 0
--- orig/libguile/numbers.c 2006-11-29 18:09:22.393764800 +0100
+++ mod/libguile/numbers.c 2006-11-29 18:10:22.319934400 +0100
@@ -4416,12 +4416,6 @@
intbig:
