Talk:Long multiplication: Difference between revisions
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Wouldn't it be appropriate to replace this task with [http://en.wikipedia.org/wiki/Bignum arbitrary-precision arithmetic] implementation? I.e. long to long +, -, *, /, and long to short +, -, *, /. The divisions are to be implemented in a complete form (result + remainder). |
Wouldn't it be appropriate to replace this task with [http://en.wikipedia.org/wiki/Bignum arbitrary-precision arithmetic] implementation? I.e. long to long +, -, *, /, and long to short +, -, *, /. The divisions are to be implemented in a complete form (result + remainder). |
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Hi [[Dmitry-kazakov]]. Yes that makes sense. |
Hi [[User_talk:Dmitry-kazakov]]. Yes that makes sense. |
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For the moment I'll switch this task to be a member of [[:Category:Arbitrary precision]]. |
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IIRC the Newton Raphson Kontorovich method can be used to speed up the division. It |
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looks interesting.... |
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Re: long/short implementations... I spotted the Ada Rational Arithmetic |
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sample code with "'''long''' + '''short'''" and considered replicating. |
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But by the time if counted all the combinations I ran out of |
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fingers and toes. E.g. one would have to combine the '''short...''', |
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'''short''' '''short''', '''short''', '''long''', '''long''' '''long''', |
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'''long...''' for '''int''', '''real''', '''compl''' for the operators |
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"+", "-", "/", "*", "%", "%*", "**", etc ... ALSO: ×, ÷, ... |
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'''abs''', '''over''', '''mod''' '''up''', '''bin''' etc ... together |
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with "+:=", "-:=" etc ... |
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Result: No more toes... I think C++/Ada templates can manage this kind of |
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complexity. |
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The [[[ALGOL 68]]] standard had a shorthand/template ≮L≯ for this. e.g. |
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'''op''' ≮÷*, %*, ÷×, %×, '''mod'''≯ = (L '''int''' a, i) L '''int''': ... |
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But this for the compiler writer, and not available to programmers. |
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[[User:NevilleDNZ|NevilleDNZ]] 10:56, 26 February 2009 (UTC) |
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Revision as of 10:56, 26 February 2009
BigNum
Wouldn't it be appropriate to replace this task with arbitrary-precision arithmetic implementation? I.e. long to long +, -, *, /, and long to short +, -, *, /. The divisions are to be implemented in a complete form (result + remainder).
Hi User_talk:Dmitry-kazakov. Yes that makes sense. For the moment I'll switch this task to be a member of Category:Arbitrary precision. IIRC the Newton Raphson Kontorovich method can be used to speed up the division. It looks interesting....
Re: long/short implementations... I spotted the Ada Rational Arithmetic sample code with "long + short" and considered replicating. But by the time if counted all the combinations I ran out of fingers and toes. E.g. one would have to combine the short..., short short, short, long, long long, long... for int, real, compl for the operators "+", "-", "/", "*", "%", "%*", "**", etc ... ALSO: ×, ÷, ... abs, over, mod up, bin etc ... together with "+:=", "-:=" etc ...
Result: No more toes... I think C++/Ada templates can manage this kind of complexity.
The [[[ALGOL 68]]] standard had a shorthand/template ≮L≯ for this. e.g.
op ≮÷*, %*, ÷×, %×, mod≯ = (L int a, i) L int: ...
But this for the compiler writer, and not available to programmers.
NevilleDNZ 10:56, 26 February 2009 (UTC)