Fixnum::{MIN,MAX}

N

Nikolai Weibull

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=E2=80=99s kind of nice to have the=
se
kinds of limits for certain algorithms and =E2=80=9Cdefault=E2=80=9D valu=
es. Any
input?,
nikolai

--=20
Nikolai Weibull: now available free of charge at http://bitwi.se/!
Born in Chicago, IL USA; currently residing in Gothenburg, Sweden.
main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}
 
J

James Edward Gray II

This may be silly, considering that Fixnums are converted to =20
Bignums if
necessary, but is there no room for having MIN and MAX constants for
Fixnums? This is my C talking, but it=92s kind of nice to have these
kinds of limits for certain algorithms and =93default=94 values. Any
input?,
Click to expand...

I too have wished for them in the past.

James Edward Gray II
 
A

Ara.T.Howard

--8323328-1747698051-1122498746=:4734
Content-Type: MULTIPART/MIXED; BOUNDARY="8323328-1747698051-1122498746=:4734"

This message is in MIME format. The first part should be readable text,
while the remaining parts are likely unreadable without MIME-aware tools.

--8323328-1747698051-1122498746=:4734
Content-Type: TEXT/PLAIN; charset=X-UNKNOWN; format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE

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=E2=80=99s kind of nice to have the= se
kinds of limits for certain algorithms and =E2=80=9Cdefault=E2=80=9D valu= es. Any
input?,
nikolai
Click to expand...

awesome! i have this everywhere:

class Fixnum
N_BYTES =3D [42].pack('i').size
N_BITS =3D N_BYTES * 8
MAX =3D 2 ** (N_BITS - 2) - 1
MIN =3D -MAX - 1
end

cheers.

-a
--=20
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
| 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
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D

--8323328-1747698051-1122498746=:4734--
--8323328-1747698051-1122498746=:4734--
 
D

Daniel Berger

Ara.T.Howard said:
On Thu, 28 Jul 2005, Nikolai Weibull wrote:
=20
This may be silly, considering that Fixnums are converted to Bignums i= f
necessary, but is there no room for having MIN and MAX constants for
Fixnums? This is my C talking, but it=92s kind of nice to have these
kinds of limits for certain algorithms and =93default=94 values. Any
input?,
nikolai
Click to expand...
=20
=20
awesome! i have this everywhere:
=20
class Fixnum
N_BYTES =3D [42].pack('i').size
N_BITS =3D N_BYTES * 8
MAX =3D 2 ** (N_BITS - 2) - 1
MIN =3D -MAX - 1
end
=20
cheers.
=20
-a
Click to expand...

Signed or unsigned max?

Solaris 10:

/* maxnum.c */
#include <stdio.h>
#include <values.h>

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
 
A

Ara.T.Howard

--8323328-1742129316-1122500183=:4734
Content-Type: MULTIPART/MIXED; BOUNDARY="8323328-1742129316-1122500183=:4734"

This message is in MIME format. The first part should be readable text,
while the remaining parts are likely unreadable without MIME-aware tools.

--8323328-1742129316-1122500183=:4734
Content-Type: TEXT/PLAIN; charset=X-UNKNOWN; format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE

Ara.T.Howard said:
On Thu, 28 Jul 2005, Nikolai Weibull wrote:
=20
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=92s kind of nice to have these
kinds of limits for certain algorithms and =93default=94 values. Any
input?,
nikolai
Click to expand...
=20
=20
awesome! i have this everywhere:
=20
class Fixnum
N_BYTES =3D [42].pack('i').size
N_BITS =3D N_BYTES * 8
MAX =3D 2 ** (N_BITS - 2) - 1
MIN =3D -MAX - 1
end
=20
cheers.
=20
-a
Click to expand...

Signed or unsigned max?
Click to expand...

maybe we are talking at cross purposes: as far as i know there is no such a=
s 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 =3D [42].pack('i').size
N_BITS =3D N_BYTES * 8
MAX =3D 2 ** (N_BITS - 2) - 1
MIN =3D -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 <stdio.h>
#include <values.h>

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
Click to expand...

sure - but these are ints not fixnums ?

cheers.

-a
--=20
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
| 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
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D

--8323328-1742129316-1122500183=:4734--
--8323328-1742129316-1122500183=:4734--
 
D

Daniel Berger

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 <stdio.h>
#include <values.h>

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
Click to expand...


sure - but these are ints not fixnums ?
Click to expand...

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
 
N

Nikolai Weibull

Daniel said:
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=E2=80=99s kind= of
nice to have these kinds of limits for certain algorithms and
=E2=80=9Cdefault=E2=80=9D values. Any input?,
nikolai
Click to expand...
awesome! i have this everywhere:

class Fixnum
N_BYTES =3D [42].pack('i').size
N_BITS =3D N_BYTES * 8
MAX =3D 2 ** (N_BITS - 2) - 1
MIN =3D -MAX - 1
end

cheers.
Click to expand...
Click to expand...
Signed or unsigned max?
Click to expand...

I don=E2=80=99t know if you=E2=80=99re trying to be clever, but as far as=
I know, it=E2=80=99d
be the value of LONG_MAX, as that=E2=80=99s how Fixnums are currently bei=
ng
stored. And I don=E2=80=99t see how it matters if you=E2=80=99re on a 32=
or 64 bit
machine (below), as all one=E2=80=99s interested in is the maximum value =
that
can be stored in a Fixnum (for sentinel values and so on). Ara=E2=80=99s
suggestion is a bit flawed, as it assumes a two=E2=80=99s-complement arit=
hmetic
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 =E2=80=9Cpossible=E2=80=9D solutions to s=
uch a problem,
nikolai
djberge@~/programming/C-570>gcc -Wall -m64 -o maxnum maxnum.c
djberge@~/programming/C-571>./maxnum
Max int: 2147483647
Max long: 9223372036854775807
Click to expand...

--=20
Nikolai Weibull: now available free of charge at http://bitwi.se/!
Born in Chicago, IL USA; currently residing in Gothenburg, Sweden.
main(){printf(&linux["\021%six\012\0"],(linux)["have"]+"fun"-97);}
 
A

Ara.T.Howard

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.
Click to expand...

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
--
===============================================================================
| 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
===============================================================================
 
D

Daniel Berger

Ara.T.Howard said:
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
Click to expand...

There is if there's an Integer::MAX. :-D

Dan
 
A

Ara.T.Howard

Sure, though its value would fluctuate with the amount of memory
currently available,
Click to expand...

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
--
===============================================================================
| 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
===============================================================================
 

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