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| From | Ike Naar <ike@sverige.freeshell.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: is the < operator transitive? |
| Date | 2011-10-09 12:54 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <slrn3vfsj936cl.45g.ike@sverige.freeshell.org> (permalink) |
| References | (1 earlier) <j6nhm0$sh9$1@speranza.aioe.org> <4e916206$0$1389$4fafbaef@reader2.news.tin.it> <slrnj92r4q.9jd.willem@toad.stack.nl> <slrn3vfsj934bp.792.ike@sverige.freeshell.org> <slrnj935he.pt6.willem@toad.stack.nl> |
On 2011-10-09, Willem <willem@toad.stack.nl> wrote:
> Ike Naar wrote:
> ) On 2011-10-09, Willem <willem@toad.stack.nl> wrote:
> )> The C way to handle this would be to have a (varargs) function
> )> increasing(...), which you would then call as increasing(a,b,c),
> )> which returns true if a<b<c in the mathematical sense, and which
> )> (listen very carefully) evaluates b only once.
> )
> ) Wouldn't this lead to a combinatorial explosion of functions?
>
> You perhaps missed the 'varargs' bit:
No, I did not miss that, I was trying to keep the examples simple.
> increasing(a,b,c,d,e,f) -> a<b<c<d<e<f
>
> ) a < b < c -> increasing(a,b,c)
> ) a <= b <= c -> younameit0(a,b,c)
> Yup, one for each inequality operator, that's 4.
But if the number of variables increases (when using varargs),
so does the number of combinations.
> ) a <= b < c -> younameit1(a,b,c)
> I can see the need for this, to check if a value is inside a certain range,
> where both ends can be closed or open.
It's not so far-fetched. Here is a common idiom in C:
/* precondition for evaluating a[i] where a has N_A elements */
0 <= i < N_A
> That's a different approach from what I proposed above.
> Still, you get 4 combinations in total.
That's 2^n if there are n operators in the general (varargs) case.
> ) a < b == c -> younameit2(a,b,c)
> I fail to see the need for this.
Use your imagination.
> ) ...
> ) a < b > c -> younameitn(a,b,c)
> That's a different set, where you check if one element is smaller than a
> number of others. Again, 4 functions if you want all of them.
Again, 2^n in the varargs case.
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is the < operator transitive? Francois Grieu <fgrieu@gmail.com> - 2011-10-07 19:10 +0200
Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-07 13:44 -0500
Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 18:50 +0000
Re: is the < operator transitive? Keith Thompson <kst-u@mib.org> - 2011-10-07 12:42 -0700
Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 20:23 +0000
Re: is the < operator transitive? Patrick Scheible <kkt@zipcon.net> - 2011-10-07 14:29 -0700
Re: is the < operator transitive? Keith Thompson <kst-u@mib.org> - 2011-10-07 16:49 -0700
Re: is the < operator transitive? Patrick Scheible <kkt@zipcon.net> - 2011-10-07 19:19 -0700
Re: is the < operator transitive? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-08 09:57 -0400
Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-08 13:17 +0100
Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-08 06:06 -0700
Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-08 14:48 +0100
Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-08 07:18 -0700
Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-08 15:19 +0100
Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 18:50 +0000
Re: is the < operator transitive? jacob navia <jacob@spamsink.net> - 2011-10-07 21:23 +0200
Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 20:24 +0000
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 16:40 -0400
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-07 23:12 +0100
Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-07 15:28 -0700
Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-07 15:31 -0700
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-07 23:36 +0100
Re: is the < operator transitive? Patrick Scheible <kkt@zipcon.net> - 2011-10-07 16:18 -0700
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 10:32 +0100
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 18:30 -0400
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 00:21 +0100
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 21:33 -0400
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 10:45 +0100
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-08 14:02 -0400
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 21:49 +0100
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-08 17:17 -0400
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 22:59 +0100
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-08 21:33 -0400
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-09 09:09 +0100
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-09 07:00 -0400
Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-09 01:12 +0100
Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-09 08:55 +0100
Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-07 18:16 -0500
Re: is the < operator transitive? David Thompson <dave.thompson2@verizon.net> - 2011-10-18 02:03 -0400
Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-20 18:03 -0500
Re: is the < operator transitive? Keith Thompson <kst-u@mib.org> - 2011-10-07 16:50 -0700
Re: is the < operator transitive? "io_x" <a@b.c.invalid> - 2011-10-09 11:00 +0200
Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 09:42 +0000
Re: is the < operator transitive? Ike Naar <ike@sverige.freeshell.org> - 2011-10-09 12:20 +0000
Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 12:40 +0000
Re: is the < operator transitive? Ike Naar <ike@sverige.freeshell.org> - 2011-10-09 12:54 +0000
Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 13:04 +0000
Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-09 15:34 +0100
Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 15:08 +0000
Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-09 12:14 -0500
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 15:36 -0400
Re: is the < operator transitive? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-07 20:00 -0400
Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 21:38 -0400
Re: is the < operator transitive? Francois Grieu <fgrieu@gmail.com> - 2011-10-09 21:40 +0200
Re: is the < operator transitive? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-09 16:34 -0400
Re: is the < operator transitive? Francois Grieu <fgrieu@gmail.com> - 2011-10-11 14:08 +0200
Re: is the < operator transitive? Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 16:14 -0800
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