> On Jul 27, 2017, at 6:27 PM, Eric Siegerman <pub08-...@davor.org> wrote: > > On Thu, Jul 27, 2017 at 08:20:50AM +0000, David T. via gnucash-devel wrote: >> I think of the decimal placement as applying to the final number in the field >> (as a sort of edit mask, if you will), rather than a preprocessing function >> that would apply to every element in an equation. > > I'm not sure that would quite work either. > > Currently, for simple numbers with no arithmetic, "1000" gets > auto-decimal-pointed ("scaled" hereafter), but "4.50" doesn't, > which are both just what one wants. The same should apply in > formulas (I think! -- but more about that at the end). Assuming > two auto-decimal places, consider: > 1000 + 4.50 > > I (think I) want the first term to get scaled, but not the > second, giving a result of 14.50. > > OK, so how about we scale each term separately, so that: > 1000 * 3 + 450 -> 34.50 > but also: > 1000 * 3 + 4.50 -> 34.50 > ("->" meaning "yields a result of", since "=" just looks wrong > under the circumstances :-) ). > > But then: > 10.00 * 3 + 4.50 -> 34.50 > We didn't want to scale the first term after all. > > I've thought of a couple of different approaches: > - scale each term's resulting value if the term only contains > integers: > 1000*3 + 4000 -> 30 + 40 = 70.00 > 1000*3 + 4000. -> 30 + 4000 = 4030.00 > 1000*3. + 4000 -> 3000 + 40 = 3040.00 > 1000*3. + 4000. -> 3000 + 4000 = 7000.00 > > - scale each term's *first* number if it's an integer, > but never second or subsequent numbers: > 1000 * 3 -> 30 > 1000 * 3. -> 30 > 1000. * 3 -> 3000 > 1000. * 3. -> 1000 > This is based on the thought that ($20 * $3) is meaningless; > it only makes sense to multiply money by something that isn't > money > > But neither of those works in all situations. > > > The easiest way out, I think, is to never scale formulas at all, > only simple numbers. So: > 4000 -> 40.00 # as currently happens > 40. -> 40.00 # likewise > But: > 4000+1 -> 4001.00 > > That's how my truly ancient copy of Excel behaves. (I don't > have access to a modern one.) > > > Or perhaps: for formulas, scale the final result (as you say), > but only if *all* of the numeric values the user typed are > integers: > 1000*3 + 4000 -> 70.00 > 1000*3 + 4000. -> 7000.00 > 1000*3. + 4000 -> 7000.00 > 1000.*3 + 4000 -> 7000.00 > > That could boil down to: > Scale the final result unless the original input string > contains any "."s (or ","s depending on locale) > (without even any need to worry whether it's a number or > a formula). > > But given that it's not entirely clear how even a simple: > 1000 + 4.50 > should behave, anything with any subtlety at all is going to want > a fair amount of testing to see whether people actually find it > usable. So an unsubtle approach like "never scale formulas" is > probably the safest place to start.
I agree that the only sane way to have auto-decimal is to disable it if the input is a formula. The other sane approach is to remove it completely. Regards, John Ralls _______________________________________________ gnucash-devel mailing list gnucash-devel@gnucash.org https://lists.gnucash.org/mailman/listinfo/gnucash-devel