# Fixnum::{MIN,MAX}
**URL:** https://rubytalk.org/t/fixnum-min-max/19779
**Category:** ruby-talk
**Created:** [27 July 2005 21:00 UTC](https://rubytalk.org/t/fixnum-min-max/19779 "2005-07-27T21:00:28Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@Nikolai\_Weibull](https://rubytalk.org/u/Nikolai_Weibull)
#### Post date: [27 July 2005 21:00 UTC](https://rubytalk.org/t/fixnum-min-max/19779/1 "2005-07-27T21:00:28Z")
This may be silly, considering that Fixnums are converted to Bignums if
necessary, but is there no room for having MIN and MAX constants for
Fixnums? This is my C talking, but it’s kind of nice to have these
kinds of limits for certain algorithms and “default” values. Any
input?,
nikolai
> **···**
>
> --
> Nikolai Weibull: now available free of charge at [http://bitwi.se/](http://bitwi.se/)!
> Born in Chicago, IL USA; currently residing in Gothenburg, Sweden.
> main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}
---
### Author:  [@James\_Edward\_Gray\_II](https://rubytalk.org/u/James_Edward_Gray_II)
#### Post date: [27 July 2005 21:06 UTC](https://rubytalk.org/t/fixnum-min-max/19779/2 "2005-07-27T21:06:05Z")
I too have wished for them in the past.
James Edward Gray II
> **···**
>
> On Jul 27, 2005, at 4:00 PM, Nikolai Weibull wrote:
>
> > This may be silly, considering that Fixnums are converted to Bignums if
> > necessary, but is there no room for having MIN and MAX constants for
> > Fixnums? This is my C talking, but it’s kind of nice to have these
> > kinds of limits for certain algorithms and “default” values. Any
> > input?,
---
### Author:  [@Ara.T.Howard6](https://rubytalk.org/u/Ara.T.Howard6)
#### Post date: [27 July 2005 21:12 UTC](https://rubytalk.org/t/fixnum-min-max/19779/3 "2005-07-27T21:12:28Z")
awesome! i have this everywhere:
class Fixnum
N\_BYTES = [42].pack('i').size
N\_BITS = N\_BYTES \* 8
MAX = 2 \*\* (N\_BITS - 2) - 1
MIN = -MAX - 1
end
cheers.
-a
> **···**
>
> On Thu, 28 Jul 2005, Nikolai Weibull wrote:
>
> > This may be silly, considering that Fixnums are converted to Bignums if
> > necessary, but is there no room for having MIN and MAX constants for
> > Fixnums? This is my C talking, but it’s kind of nice to have these
> > kinds of limits for certain algorithms and “default” values. Any
> > input?,
> > nikolai
>
> # --
>
> > email :: ara [dot] t [dot] howard [at] noaa [dot] gov
> > phone :: 303.497.6469
> > My religion is very simple. My religion is kindness.
> > --Tenzin Gyatso
>
> ===============================================================================
---
### Author:  [@Berger\_Daniel1](https://rubytalk.org/u/Berger_Daniel1)
#### Post date: [27 July 2005 21:24 UTC](https://rubytalk.org/t/fixnum-min-max/19779/4 "2005-07-27T21:24:39Z")
Ara.T.Howard wrote:
> > This may be silly, considering that Fixnums are converted to Bignums if
> > necessary, but is there no room for having MIN and MAX constants for
> > Fixnums? This is my C talking, but it’s kind of nice to have these
> > kinds of limits for certain algorithms and “default” values. Any
> > input?,
> > nikolai
>
> awesome! i have this everywhere:
>
> class Fixnum
> N\_BYTES = [42].pack('i').size
> N\_BITS = N\_BYTES \* 8
> MAX = 2 \*\* (N\_BITS - 2) - 1
> MIN = -MAX - 1
> end
>
> cheers.
>
> -a
Signed or unsigned max?
Solaris 10:
/\* maxnum.c \*/
#include \
#include \
int main(){
printf("Max int: %i\n", MAXINT);
printf("Max long: %li\n", MAXLONG);
return 0;
}
djberge@~/programming/C-568\>gcc -Wall -o maxnum maxnum.c
djberge@~/programming/C-569\>./maxnum
Max int: 2147483647
Max long: 2147483647
djberge@~/programming/C-570\>gcc -Wall -m64 -o maxnum maxnum.c
djberge@~/programming/C-571\>./maxnum
Max int: 2147483647
Max long: 9223372036854775807
Regards,
Dan
> **···**
>
> > On Thu, 28 Jul 2005, Nikolai Weibull wrote:
---
### Author:  [@Ara.T.Howard6](https://rubytalk.org/u/Ara.T.Howard6)
#### Post date: [27 July 2005 21:36 UTC](https://rubytalk.org/t/fixnum-min-max/19779/5 "2005-07-27T21:36:41Z")
> Ara.T.Howard wrote:
>
> > > This may be silly, considering that Fixnums are converted to Bignums if
> > > necessary, but is there no room for having MIN and MAX constants for
> > > Fixnums? This is my C talking, but its kind of nice to have these
> > > kinds of limits for certain algorithms and default values. Any
> > > input?,
> > > nikolai
> >
> > awesome! i have this everywhere:
> >
> > class Fixnum
> > N\_BYTES = [42].pack('i').size
> > N\_BITS = N\_BYTES \* 8
> > MAX = 2 \*\* (N\_BITS - 2) - 1
> > MIN = -MAX - 1
> > end
> >
> > cheers.
> >
> > -a
>
> Signed or unsigned max?
maybe we are talking at cross purposes: as far as i know there is no such as an
'unsigned' Fixnum - we only have signed fixnums which loses one bit and the
VALUE/Fixnum thing which loses another. so i assumed the OP wanted to know the
largest/smallest value that could be represented by a fixnum:
harp:~ \> cat a.rb
class Fixnum
N\_BYTES = [42].pack('i').size
N\_BITS = N\_BYTES \* 8
MAX = 2 \*\* (N\_BITS - 2) - 1
MIN = -MAX - 1
end
p(Fixnum::MAX)
p(Fixnum::MAX.class)
p((Fixnum::MAX + 1).class)
p(Fixnum::MIN)
p(Fixnum::MIN.class)
p((Fixnum::MIN - 1).class)
harp:~ \> ruby a.rb
1073741823
Fixnum
Bignum
-1073741824
Fixnum
Bignum
make sense?
> Solaris 10:
>
> /\* maxnum.c \*/
> #include \
> #include \
>
> int main(){
> printf("Max int: %i\n", MAXINT);
> printf("Max long: %li\n", MAXLONG);
>
> return 0;
> }
>
> djberge@~/programming/C-568\>gcc -Wall -o maxnum maxnum.c
> djberge@~/programming/C-569\>./maxnum
> Max int: 2147483647
> Max long: 2147483647
>
> djberge@~/programming/C-570\>gcc -Wall -m64 -o maxnum maxnum.c
> djberge@~/programming/C-571\>./maxnum
> Max int: 2147483647
> Max long: 9223372036854775807
sure - but these are ints not fixnums ?
cheers.
-a
> **···**
>
> On Thu, 28 Jul 2005, Daniel Berger wrote:
>
> > > On Thu, 28 Jul 2005, Nikolai Weibull wrote:
>
> # --
>
> > email :: ara [dot] t [dot] howard [at] noaa [dot] gov
> > phone :: 303.497.6469
> > My religion is very simple. My religion is kindness.
> > --Tenzin Gyatso
>
> ===============================================================================
---
### Author:  [@Nikolai\_Weibull](https://rubytalk.org/u/Nikolai_Weibull)
#### Post date: [27 July 2005 21:57 UTC](https://rubytalk.org/t/fixnum-min-max/19779/6 "2005-07-27T21:57:41Z")
Daniel Berger wrote:
> Ara.T.Howard wrote:
> \> \> This may be silly, considering that Fixnums are converted to
> \> \> Bignums if necessary, but is there no room for having MIN and MAX
> \> \> constants for Fixnums? This is my C talking, but it’s kind of
> \> \> nice to have these kinds of limits for certain algorithms and
> \> \> “default” values. Any input?,
> \> \> nikolai
> \> awesome! i have this everywhere:
> \>
> \> class Fixnum
> \> N\_BYTES = [42].pack('i').size
> \> N\_BITS = N\_BYTES \* 8
> \> MAX = 2 \*\* (N\_BITS - 2) - 1
> \> MIN = -MAX - 1
> \> end
> \>
> \> cheers.
> Signed or unsigned max?
I don’t know if you’re trying to be clever, but as far as I know, it’d
be the value of LONG\_MAX, as that’s how Fixnums are currently being
stored. And I don’t see how it matters if you’re on a 32 or 64 bit
machine (below), as all one’s interested in is the maximum value that
can be stored in a Fixnum (for sentinel values and so on). Ara’s
suggestion is a bit flawed, as it assumes a two’s-complement arithmetic
for the MIN calculation, but who can blame him? 🙂
I was perhaps not so much saying that we \_must\_ have MAX and MIN of
Fixnums, as a way of having good sentinel values when dealing with
Fixnums. I was half-expecting a whole thread on duck-typing,
meta-programming, IoC, or other “possible” solutions to such a problem,
nikolai
> **···**
>
> > \> On Thu, 28 Jul 2005, Nikolai Weibull wrote:
>
> > djberge@~/programming/C-570\>gcc -Wall -m64 -o maxnum maxnum.c
> > djberge@~/programming/C-571\>./maxnum
> > Max int: 2147483647
> > Max long: 9223372036854775807
>
> --
> Nikolai Weibull: now available free of charge at [http://bitwi.se/\](http://bitwi.se/%5C)!
> Born in Chicago, IL USA; currently residing in Gothenburg, Sweden.
> main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}
---
### Author:  [@Berger\_Daniel1](https://rubytalk.org/u/Berger_Daniel1)
#### Post date: [27 July 2005 21:53 UTC](https://rubytalk.org/t/fixnum-min-max/19779/7 "2005-07-27T21:53:07Z")
Ara.T.Howard wrote:
\
> maybe we are talking at cross purposes: as far as i know there is no such as an
> 'unsigned' Fixnum - we only have signed fixnums which loses one bit and the
> VALUE/Fixnum thing which loses another. so i assumed the OP wanted to know the
> largest/smallest value that could be represented by a fixnum:
>
> harp:~ \> cat a.rb
> class Fixnum
> N\_BYTES = [42].pack('i').size
> N\_BITS = N\_BYTES \* 8
> MAX = 2 \*\* (N\_BITS - 2) - 1
> MIN = -MAX - 1
> end
>
> p(Fixnum::MAX)
> p(Fixnum::MAX.class)
> p((Fixnum::MAX + 1).class)
>
> p(Fixnum::MIN)
> p(Fixnum::MIN.class)
> p((Fixnum::MIN - 1).class)
>
> harp:~ \> ruby a.rb
> 1073741823
> Fixnum
> Bignum
> -1073741824
> Fixnum
> Bignum
>
> make sense?
>
> > Solaris 10:
> >
> > /\* maxnum.c \*/
> > #include \
> > #include \
> >
> > int main(){
> > printf("Max int: %i\n", MAXINT);
> > printf("Max long: %li\n", MAXLONG);
> >
> > return 0;
> > }
> >
> > djberge@~/programming/C-568\>gcc -Wall -o maxnum maxnum.c
> > djberge@~/programming/C-569\>./maxnum
> > Max int: 2147483647
> > Max long: 2147483647
> >
> > djberge@~/programming/C-570\>gcc -Wall -m64 -o maxnum maxnum.c
> > djberge@~/programming/C-571\>./maxnum
> > Max int: 2147483647
> > Max long: 9223372036854775807
>
> sure - but these are ints not fixnums ?
True.
But if we add Fixnum::MIN/MAX, don't we have to add Integer::MIN/MAX and Bignum::MIN/MAX? What about Numeric or Float?
My gut feeling is that this will lead to confusion. Maybe I'm wrong, though.
Dan
> **···**
>
> > On Thu, 28 Jul 2005, Daniel Berger wrote:
---
### Author:  [@Ara.T.Howard6](https://rubytalk.org/u/Ara.T.Howard6)
#### Post date: [27 July 2005 21:58 UTC](https://rubytalk.org/t/fixnum-min-max/19779/8 "2005-07-27T21:58:47Z")
you have a point. perhaps
require 'limits'
p Bignum::MAX
p Integer::MAX
etc. that was new limits could be added later...
btw. is there a Bignum::MAX?
-a
> **···**
>
> On Thu, 28 Jul 2005, Daniel Berger wrote:
>
> > True.
> >
> > But if we add Fixnum::MIN/MAX, don't we have to add Integer::MIN/MAX and Bignum::MIN/MAX? What about Numeric or Float?
> >
> > My gut feeling is that this will lead to confusion. Maybe I'm wrong, though.
>
> # --
>
> > email :: ara [dot] t [dot] howard [at] noaa [dot] gov
> > phone :: 303.497.6469
> > My religion is very simple. My religion is kindness.
> > --Tenzin Gyatso
>
> ===============================================================================
---
### Author:  [@Berger\_Daniel1](https://rubytalk.org/u/Berger_Daniel1)
#### Post date: [27 July 2005 22:03 UTC](https://rubytalk.org/t/fixnum-min-max/19779/9 "2005-07-27T22:03:14Z")
Ara.T.Howard wrote:
> **···**
>
> > On Thu, 28 Jul 2005, Daniel Berger wrote:
> >
> > > True.
> > >
> > > But if we add Fixnum::MIN/MAX, don't we have to add Integer::MIN/MAX and Bignum::MIN/MAX? What about Numeric or Float?
> > >
> > > My gut feeling is that this will lead to confusion. Maybe I'm wrong, though.
> >
> > you have a point. perhaps
> >
> > require 'limits'
> >
> > p Bignum::MAX
> > p Integer::MAX
> >
> > etc. that was new limits could be added later...
> >
> > btw. is there a Bignum::MAX?
> >
> > -a
>
> There is if there's an Integer::MAX. 😃
>
> Dan
---
### Author:  [@Nikolai\_Weibull](https://rubytalk.org/u/Nikolai_Weibull)
#### Post date: [27 July 2005 22:04 UTC](https://rubytalk.org/t/fixnum-min-max/19779/10 "2005-07-27T22:04:47Z")
Ara.T.Howard wrote:
> btw. is there a Bignum::MAX?
Sure, though its value would fluctuate with the amount of memory
currently available,
nikolai
> **···**
>
> --
> Nikolai Weibull: now available free of charge at [http://bitwi.se/\](http://bitwi.se/%5C)!
> Born in Chicago, IL USA; currently residing in Gothenburg, Sweden.
> main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}
---
### Author:  [@Ara.T.Howard6](https://rubytalk.org/u/Ara.T.Howard6)
#### Post date: [27 July 2005 22:11 UTC](https://rubytalk.org/t/fixnum-min-max/19779/11 "2005-07-27T22:11:27Z")
it does seems that way - so maybe impossibleto determine/store since saying
class Bignum
MAX = do\_something\_to\_determine
end
would exhaust memory...
an estimate as string perhaps?
-a
> **···**
>
> On Thu, 28 Jul 2005, Nikolai Weibull wrote:
>
> > Ara.T.Howard wrote:
> >
> > > btw. is there a Bignum::MAX?
> >
> > Sure, though its value would fluctuate with the amount of memory
> > currently available,
>
> # --
>
> > email :: ara [dot] t [dot] howard [at] noaa [dot] gov
> > phone :: 303.497.6469
> > My religion is very simple. My religion is kindness.
> > --Tenzin Gyatso
>
> ===============================================================================