Re: Power function as operator

On Fri, Nov 22, 2013 at 5:12 PM, Kris Craig <kris.craig@gmail.com> wrote: > > > > On Fri, Nov 22, 2013 at 3:03 PM, Sherif Ramadan <theanomaly.is@gmail.com>wrote: > >> > On Fri, Nov 22, 2013 at 3:17 PM, Niel Archer < >> spam-free@blueyonder.co.uk >> > >wrote: >> > >> > > Hi, >> > > >> > > >> > > > So: >> > > > -3 ** 2 == -9 >> > > >> > > Shouldn't this be +9 >> > > >> > > >> > >> >> To add to this note, the negation operator in PHP is left-associative, >> whereas the patch here makes ** right-associative. So the result is >> expected to be -9 and not 9 given the static scalar expression should be >> evaluated as -(3**2) based on operator associativity. >> > > This really bothers me. I understand that, since "-3" is basically > treated as "(-1) * 3", we'd end-up with odd behavior like this. But can't > we find a way around that? "-3 ** 2 == -9" would just open-up the flood > gates to code bugs all over the place. Can't we make it so that "-3" is > treated as "(-1 * 3)" instead of "(-1) * 3", or would that break things? > Every calculator I've tried today does "-3 ** 2 == -9" - Mac built-in calculator - Google search calculator https://www.google.com/search?q=-3+%5E+2 - Wolfram Alpha http://www.wolframalpha.com/input/?i=-3+%5E+2 In my GMAT prep book it explains that you have to enclose the negative in parentheses like (-3) ^ 2 to get +9. So while it may seem counter-intuitive, that's how math and the order of operations work.