Awesome, thanks! I just can't match "arbitrary precision" and "float" expressions: 1/3 is rational, but can't be represented with float-like data structure. The same problem is with arbitrary precision uint: what will ^uint-1 be?
So, arbitrary precision int and user-specified-precision float is great and wanted, but arbitrary precision uint and float is nonsense. On 2017. aug. 19., Szo 19:27 Michael Jones <michael.jo...@gmail.com> wrote: > Jimmy, thank you for the tip! i went there and added my modest suggestions > to the proposal. > https://github.com/golang/go/issues/19623 > > Tamás, you make a very important point. It is one that GRI did a very good > job of in big.Float. The question of how to specify precision for > variable-precision floating point math is tricky. He does it by making each > variable carry a precision, allows users to change this, and has rules for > the precision of results of operations between values of same or differing > precisions. > > One implication of this issue is in handling something like 1/3. I have > software that converts such expressions to big.rat and then once the target > big.float exists with its chosen precision, does the conversion. In one of > these cases I have three different extended precisions going in the same > application, one for parameters (50 digits plus guard digits), one for > computation (less or more depending on dynamic precision needs), and one > fast and tuned doubled-precision (128-bit float) for very intensive inner > computations. > > Situations like this make it a little complicated for fractions and also > for constants (Pi, Tau, E, ...), which are no longer constants but must be > functions since they need to work more or less based on the precision of > the desired result. > > A little messy. > > On Sat, Aug 19, 2017 at 10:03 AM, Tamás Gulácsi <tgulacs...@gmail.com> > wrote: > >> What is an arbitrary precision float? 1/3, Pi, ✓2 ? >> >> -- >> 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. >> > > > > -- > Michael T. Jones > michael.jo...@gmail.com > -- 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.
