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July 03, 2014 Decimal Numbers | ||||
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A candidate implementation of decimal numbers (arbitrary-precision floating-point numbers) is available for review at https://github.com/andersonpd/eris/tree/master/eris/decimal. This is a substantial rework of an earlier implementation which was located at https://github.com/andersonpd/decimal. This is a D language implementation of the General Decimal Arithmetic Specification (http://www.speleotrove.com/decimal/decarith.pdf), which is compliant with IEEE-754 and other standards as noted in the specification. The current implementation is not complete; there are a lot of TODOs and NOTEs scattered throughout the code, but all the arithmetic and miscellaneous operations listed in the spec are working, along with decimal versions of most of the functions and constants in std.math. I think it is far enough along for effective review. Briefly, this software adds the capability of properly rounded arbitrary-precision floating-point arithmetic to the D language. All arithmetic operations are governed by a "context", which specifies the precision (number of decimal digits) and rounding mode for the operations. This same functionality exists in most modern computer languages (for example, java.math.BigDecimal). Unlike Java, however, which uses function syntax for arithmetic ops (add(BigDecimal, BigDecimal), etc.), in D the same arithmetic operators that work for floats or doubles work for decimal numbers. (Of course!) In this implementation decimal numbers having different contexts are different types. The types are specified using template parameters for the precision, maximum exponent value and rounding mode. This means that Decimal!(9,99,Rounding.HALF_EVEN) is a different type than Decimal!(19,199,Rounding.HALF_DOWN). They are largely interoperable, however. Different decimal types can be cast to and from each other. There are three standard decimal structs which fit into 32-, 64- and 128-bits of memory, with 7, 16 and 34 digit precision, respectively. These are used for compact storage; they are converted to their corresponding decimal numbers for calculation. They bear the same relation to decimal numbers as Walter's half-float type does to floats. (http://www.drdobbs.com/cpp/implementing-half-floats-in-d/240146674). Implementation of these still needs a little work, and will be added to github very shortly. Major TODO items: 1) The current underlying integer type uses my own big integer struct (eris.integer.extended) rather than std.bigint. This was mainly due to problems with constness and CTFE of BigInts. These problems have since been resolved, but I didn't want to switch over to BigInts until everything was working for fear of introducing new bugs. 2) Integration of Decimal32, Decimal64 and Decimal128 structs are not complete. (See above.) 3) Conversion to and from floats, doubles and reals is currently working but it is slow. (Conversion is through strings: double to string to decimal and vice versa.) 4) Still incomplete implementations of some functions in decimal.math: expm1, acosh, atanh, possibly others. 5) More unit tests (always!). |
July 03, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Paul D Anderson | Sorry for the unusual formatting. Paul |
July 04, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Paul D Anderson Attachments:
| On 3 Jul 2014 23:00, "Paul D Anderson via Digitalmars-d-announce" < digitalmars-d-announce@puremagic.com> wrote: > > A candidate implementation of decimal numbers (arbitrary-precision floating-point numbers) is available for review at https://github.com/andersonpd/eris/tree/master/eris/decimal. This is a substantial rework of an earlier implementation which was located at https://github.com/andersonpd/decimal. > > This is a D language implementation of the General Decimal Arithmetic Specification (http://www.speleotrove.com/decimal/decarith.pdf), which is compliant with IEEE-754 and other standards as noted in the specification. > > The current implementation is not complete; there are a lot of TODOs and NOTEs > scattered throughout the code, but all the arithmetic and miscellaneous operations listed in the spec are working, along with decimal versions of most > of the functions and constants in std.math. I think it is far enough along for > effective review. > > Briefly, this software adds the capability of properly rounded arbitrary-precision floating-point arithmetic to the D language. All arithmetic > operations are governed by a "context", which specifies the precision (number of > decimal digits) and rounding mode for the operations. This same functionality > exists in most modern computer languages (for example, java.math.BigDecimal). > Unlike Java, however, which uses function syntax for arithmetic ops > (add(BigDecimal, BigDecimal), etc.), in D the same arithmetic operators that > work for floats or doubles work for decimal numbers. (Of course!) > > In this implementation decimal numbers having different contexts are different > types. The types are specified using template parameters for the precision, > maximum exponent value and rounding mode. This means that > Decimal!(9,99,Rounding.HALF_EVEN) is a different type than > Decimal!(19,199,Rounding.HALF_DOWN). They are largely interoperable, however. > Different decimal types can be cast to and from each > other. > > There are three standard decimal structs which fit into 32-, 64- and 128-bits of > memory, with 7, 16 and 34 digit precision, respectively. These are used for > compact storage; they are converted to their corresponding decimal numbers for > calculation. They bear the same relation to decimal numbers as Walter's half-float type does to floats. (http://www.drdobbs.com/cpp/implementing-half-floats-in-d/240146674). Implementation of these still needs a little work, and will be added to github > very shortly. > > Major TODO items: > > 1) The current underlying integer type uses my own big integer struct > (eris.integer.extended) rather than std.bigint. This was mainly due to problems > with constness and CTFE of BigInts. These problems have since been resolved, but > I didn't want to switch over to BigInts until everything was working for fear of > introducing new bugs. > > 2) Integration of Decimal32, Decimal64 and Decimal128 structs are not complete. > (See above.) > > 3) Conversion to and from floats, doubles and reals is currently working but it > is slow. (Conversion is through strings: double to string to decimal and vice > versa.) > > 4) Still incomplete implementations of some functions in decimal.math: expm1, > acosh, atanh, possibly others. > > 5) More unit tests (always!). Nice job. I would also add: 6) Rename the file decimal.d to package.d, and module eris.decimal.decimal to eris.decimal |
July 04, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Iain Buclaw | On Friday, 4 July 2014 at 06:43:15 UTC, Iain Buclaw via Digitalmars-d-announce wrote:
>
> 6) Rename the file decimal.d to package.d, and module eris.decimal.decimal
> to eris.decimal
Thanks, will do.
Paul
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July 04, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Paul D Anderson | On Thursday, 3 July 2014 at 21:55:42 UTC, Paul D Anderson wrote:
> A candidate implementation of decimal numbers (arbitrary-precision
> floating-point numbers) is available for review at
> https://github.com/andersonpd/eris/tree/master/eris/decimal. This is a
> substantial rework of an earlier implementation which was located at
> https://github.com/andersonpd/decimal.
>
> This is a D language implementation of the General Decimal Arithmetic
> Specification (http://www.speleotrove.com/decimal/decarith.pdf), which is
> compliant with IEEE-754 and other standards as noted in the specification.
>
> The current implementation is not complete; there are a lot of TODOs and NOTEs
> scattered throughout the code, but all the arithmetic and miscellaneous
> operations listed in the spec are working, along with decimal versions of most
> of the functions and constants in std.math. I think it is far enough along for
> effective review.
>
> Briefly, this software adds the capability of properly rounded
> arbitrary-precision floating-point arithmetic to the D language. All arithmetic
> operations are governed by a "context", which specifies the precision (number of
> decimal digits) and rounding mode for the operations. This same functionality
> exists in most modern computer languages (for example, java.math.BigDecimal).
> Unlike Java, however, which uses function syntax for arithmetic ops
> (add(BigDecimal, BigDecimal), etc.), in D the same arithmetic operators that
> work for floats or doubles work for decimal numbers. (Of course!)
>
> In this implementation decimal numbers having different contexts are different
> types. The types are specified using template parameters for the precision,
> maximum exponent value and rounding mode. This means that
> Decimal!(9,99,Rounding.HALF_EVEN) is a different type than
> Decimal!(19,199,Rounding.HALF_DOWN). They are largely interoperable, however.
> Different decimal types can be cast to and from each
> other.
>
> There are three standard decimal structs which fit into 32-, 64- and 128-bits of
> memory, with 7, 16 and 34 digit precision, respectively. These are used for
> compact storage; they are converted to their corresponding decimal numbers for
> calculation. They bear the same relation to decimal numbers as Walter's
> half-float type does to floats.
> (http://www.drdobbs.com/cpp/implementing-half-floats-in-d/240146674).
> Implementation of these still needs a little work, and will be added to github
> very shortly.
>
> Major TODO items:
>
> 1) The current underlying integer type uses my own big integer struct
> (eris.integer.extended) rather than std.bigint. This was mainly due to problems
> with constness and CTFE of BigInts. These problems have since been resolved, but
> I didn't want to switch over to BigInts until everything was working for fear of
> introducing new bugs.
>
> 2) Integration of Decimal32, Decimal64 and Decimal128 structs are not complete.
> (See above.)
>
> 3) Conversion to and from floats, doubles and reals is currently working but it
> is slow. (Conversion is through strings: double to string to decimal and vice
> versa.)
>
> 4) Still incomplete implementations of some functions in decimal.math: expm1,
> acosh, atanh, possibly others.
>
> 5) More unit tests (always!).
This is looking very promising!
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July 05, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Paul D Anderson | On Thursday, 3 July 2014 at 21:55:42 UTC, Paul D Anderson wrote: > A candidate implementation of decimal numbers (arbitrary-precision > floating-point numbers) is available for review at > https://github.com/andersonpd/eris/tree/master/eris/decimal. This is a > substantial rework of an earlier implementation which was located at > https://github.com/andersonpd/decimal. > > This is a D language implementation of the General Decimal Arithmetic > Specification (http://www.speleotrove.com/decimal/decarith.pdf), which is > compliant with IEEE-754 and other standards as noted in the specification. > > The current implementation is not complete; there are a lot of TODOs and NOTEs > scattered throughout the code, but all the arithmetic and miscellaneous > operations listed in the spec are working, along with decimal versions of most > of the functions and constants in std.math. I think it is far enough along for > effective review. > > Briefly, this software adds the capability of properly rounded > arbitrary-precision floating-point arithmetic to the D language. All arithmetic > operations are governed by a "context", which specifies the precision (number of > decimal digits) and rounding mode for the operations. This same functionality > exists in most modern computer languages (for example, java.math.BigDecimal). > Unlike Java, however, which uses function syntax for arithmetic ops > (add(BigDecimal, BigDecimal), etc.), in D the same arithmetic operators that > work for floats or doubles work for decimal numbers. (Of course!) > > In this implementation decimal numbers having different contexts are different > types. The types are specified using template parameters for the precision, > maximum exponent value and rounding mode. This means that > Decimal!(9,99,Rounding.HALF_EVEN) is a different type than > Decimal!(19,199,Rounding.HALF_DOWN). They are largely interoperable, however. > Different decimal types can be cast to and from each > other. > > There are three standard decimal structs which fit into 32-, 64- and 128-bits of > memory, with 7, 16 and 34 digit precision, respectively. These are used for > compact storage; they are converted to their corresponding decimal numbers for > calculation. They bear the same relation to decimal numbers as Walter's > half-float type does to floats. > (http://www.drdobbs.com/cpp/implementing-half-floats-in-d/240146674). > Implementation of these still needs a little work, and will be added to github > very shortly. > > Major TODO items: > > 1) The current underlying integer type uses my own big integer struct > (eris.integer.extended) rather than std.bigint. This was mainly due to problems > with constness and CTFE of BigInts. These problems have since been resolved, but > I didn't want to switch over to BigInts until everything was working for fear of > introducing new bugs. > > 2) Integration of Decimal32, Decimal64 and Decimal128 structs are not complete. > (See above.) > > 3) Conversion to and from floats, doubles and reals is currently working but it > is slow. (Conversion is through strings: double to string to decimal and vice > versa.) > > 4) Still incomplete implementations of some functions in decimal.math: expm1, > acosh, atanh, possibly others. > > 5) More unit tests (always!). I have spend some times fixing this and now it compiles with DMD 2.066. Also fixed some tests. https://github.com/Remotion/decimal |
July 07, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Paul D Anderson | Can you add a dub.json and submit it to the dub registry? |
July 07, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Poyeyo | On Monday, 7 July 2014 at 03:26:54 UTC, Poyeyo wrote:
> Can you add a dub.json and submit it to the dub registry?
I can do that but I want to get the 32-, 64- and 128-bit structs in place first. Probably by midweek (July 9).
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July 07, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Poyeyo | On Monday, 7 July 2014 at 03:26:54 UTC, Poyeyo wrote:
> Can you add a dub.json and submit it to the dub registry?
etcimon generated a dub.json file which I've merged into github. Thanks.
However, I am unable to register the package because it requires a version number, which I don't know how to add. I've used git tag and edited dub.selections.json, but neither seems to be the answer. Can someone enlighten me?
Paul
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July 08, 2014 Re: Decimal Numbers | ||||
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Posted in reply to Paul D Anderson | Am 07.07.2014 23:15, schrieb Paul D Anderson:
> On Monday, 7 July 2014 at 03:26:54 UTC, Poyeyo wrote:
>> Can you add a dub.json and submit it to the dub registry?
>
> etcimon generated a dub.json file which I've merged into github. Thanks.
>
> However, I am unable to register the package because it requires a
> version number, which I don't know how to add. I've used git tag and
> edited dub.selections.json, but neither seems to be the answer. Can
> someone enlighten me?
>
> Paul
git tag v0.9.0
git push --tags
should do the trick (as well as any other version instead of 0.9.0, of course).
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