Technically, a NaN in comparison with any other including NaN is false. For Cmp this creates a problem....
> On Nov 29, 2018, at 7:41 AM, Robert Engels <reng...@ix.netcom.com> wrote: > > Ah, you want a ctor that is the int value. Ok. The Raw doesn’t do this > anyway... I could add a NewI() ctor but I’m not sure it is much that > NewF(float64(x)) given the magnitude restrictions. > > If you review the gotrader you’ll see that it uses a dot import on this. If > it was just Number you lose a lot of information. I find it makes the > structures far more readable for a common type. > > Java’s BigInteger has this exact optimization when the value fits in a single > word. Go could do this too so it is a fair performance comparison IMO. > >> On Nov 29, 2018, at 7:20 AM, Jan Mercl <0xj...@gmail.com> wrote: >> >> On Thu, Nov 29, 2018 at 2:00 PM Robert Engels <reng...@ix.netcom.com> wrote: >> >> >> >> - To me type name 'fixed.Fixed' sounds like Javaism. Go code usually >> >> tries to avoid such stutter: 'sort.Interface', 'big.Int' etc. >> > To me that’s a limitation of Go with small packages like this that only >> > have a single public struct. It is based on decimal.Decimal so I’m not the >> > only one who thinks this.... >> >> I don't think we are talking about the same thing here. Go idiom is to name >> types such that they are not the same as the package qualifier (modulo case) >> at the caller site. So the exported type should be 'Int', or 'Float' or >> 'Real' or 'Number', etc., not 'FIxed' to avoid 'fixed.Fixed' at caller site. >> `var n fixed.Number` looks better to me, for example, than `var n >> fixed.Fixed`. The later actually does not even communicate any hint what the >> type could possibly be. >> >> >> - A struct with a single field could be replaced by the field itself. >> >> OTOH, it would enable coding errors by applying arithmetic operators to >> >> it directly, so it's maybe justified in this case if that was the >> >> intention. >> > It was the intention. The Raw methods are there temporarily and will be >> > removed for direct serialization via a Writer. >> >> Then it looks strange that to construct a Fixed from int64 one has to write >> 'fixed.NewF(0).FromRaw(42)'. Check the big.{Int,Float,Rat) constructors and >> setters, they are much more natural to use. >> >> >> - I'd prefer a single constructor 'New(int64)' and methods 'SetString', >> >> 'SetFloat' etc. >> > Not possible. The caller doesn’t know the int64 value. Also, think of how >> > that would look in a chained math statement. Horrible. >> >> It _is_ possible. You've misunderstood. New(n int64) returns a Fixed that >> has the _value_ of n, which of course has a different underlying int64 bit >> pattern in the private Fixed field. The caller want New(42) meaning 42 and >> does not casre about the internal, scaled value, that's just an >> implementation detail and no business of the caller. BTW: Chained math >> statements where the operators are written as function calls, above chains >> of length 2 are not seen very often. Longer ones, in many cases, well, >> that's what I'd call horrible. >> >> >> I don't consider comparing performances of 64 bit integer arithmetic and >> >> arbitrary sized arithmetic very useful. >> > Those are the alternatives to use when performing fixed place arithmetic. >> > In fact decimal.Decimal uses big Int... so it is included for reference. >> >> The point being made here is fixed size fitting to a machine word on a 64 >> bit CPU vs arbitrary sizes math libs implemented inevitably by multiple word >> structs with pointers to backing storage and the necessary allocation >> overhead. Apples to oranges. Not even in the same league. >> >> -- >> -j >> > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.