Data type representing 'Money'

Data type representing 'Money'

[Conglun Yao]

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Hi all,

Is there any data type could be used to represent 'Money'  in OCaml, similar
to BigDecimal.
I see a lot of programs using float directly. Maybe Num would be better, but
less document could be found, for example, how to represent 20.27

Or there already exist a better solution. Thanks for any help.

Conglun

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Re: [Caml-list] Data type representing 'Money'

[Edgar Friendly]

Conglun Yao wrote:
> Hi all,
> 
> Is there any data type could be used to represent 'Money'  in OCaml,
> similar to BigDecimal.
> I see a lot of programs using float directly. Maybe Num would be better,
> but less document could be found, for example, how to represent 20.27
> 
> Or there already exist a better solution. Thanks for any help.
> 
> Conglun
> 
> 
I'd do fixed point math using Num to count cents (or mills if you really
need) but displaying dollars and cents.  For example: $20.27 would
internally be represented by the number 2027, and use int arithmetic for
exact math.

If you used 63-bit ints, you'd probably get away with not even using
Num, as max_int = 4611686018427387903 would represent the dollar amount
46_116_860_184_273_879.03, just short of 50 quadrillion dollars.

E

Re: [Caml-list] Data type representing 'Money'

[Florent.Ouchet]

Hi,

Fixed point computing is okay, but the financial world used to play  
with 5 fractional digits.

Florent

"Edgar Friendly" <thelema314@gmail.com> a écrit :
> Conglun Yao wrote:
>> Hi all,
>>
>> Is there any data type could be used to represent 'Money'  in OCaml,
>> similar to BigDecimal.
>> I see a lot of programs using float directly. Maybe Num would be better,
>> but less document could be found, for example, how to represent 20.27
>>
>> Or there already exist a better solution. Thanks for any help.
>>
>> Conglun
>>
>>
> I'd do fixed point math using Num to count cents (or mills if you really
> need) but displaying dollars and cents.  For example: $20.27 would
> internally be represented by the number 2027, and use int arithmetic for
> exact math.
>
> If you used 63-bit ints, you'd probably get away with not even using
> Num, as max_int = 4611686018427387903 would represent the dollar amount
> 46_116_860_184_273_879.03, just short of 50 quadrillion dollars.
>
> E
>
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Re: [Caml-list] Data type representing 'Money'

[Richard Jones]

On Sat, May 16, 2009 at 09:23:04PM -0500, Edgar Friendly wrote:
> Conglun Yao wrote:
> > Hi all,
> > 
> > Is there any data type could be used to represent 'Money'  in OCaml,
> > similar to BigDecimal.
> > I see a lot of programs using float directly. Maybe Num would be better,
> > but less document could be found, for example, how to represent 20.27
> > 
> > Or there already exist a better solution. Thanks for any help.
> > 
> > Conglun
> > 
> > 
> I'd do fixed point math using Num to count cents (or mills if you really
> need) but displaying dollars and cents.  For example: $20.27 would
> internally be represented by the number 2027, and use int arithmetic for
> exact math.
> 
> If you used 63-bit ints, you'd probably get away with not even using
> Num, as max_int = 4611686018427387903 would represent the dollar amount
> 46_116_860_184_273_879.03, just short of 50 quadrillion dollars.

But be careful if you want to use the software on 32 bit machines.
You won't even be able to represent a single mortgage loss, nevermind
the size of your bailout!

Rich.

-- 
Richard Jones
Red Hat

RE: [Caml-list] Data type representing 'Money'

[Harrison, John R]

The recent revision of the IEEE Standard 754 for binary floating-point
arithmetic added specifications for decimal floating-point types,
specifically designed for use in financial applications. In the long
term, OCaml support for these may be a good idea.

Intel provides a library with a fairly portable software implementation
of the new decimal types here:

http://software.intel.com/en-us/articles/intel-decimal-floating-point-math-library/

And if you want to find out more about decimal arithmetic, there are
several talks and a special session on the subject at this year's
Computer Arithmetic conference, the early registration deadline for
which is tomorrow :-)

http://www.ac.usc.es/arith19/

John.