Then the browser had helped you, as you would have found that the "-" is a method for subtraction only. But it takes more time to look inside this browser... The reward is that you find gold nuggets here and there; for example, when I saw that there were a "asRomanLitteral" for the integers, I was astonished and pleased at the same time.
On Wed, Jul 16, 2014 at 1:12 PM, Max Bareis <i...@derverkoster.de> wrote: > The misunderstanding her is based in the error message of the ui. > when you write > ^ - self width. > and save, the UI writes this text into the code: > ^ only numbers may be negated ->- self width. > > More helpful would have been something like: „only literals may be negated > with - use <object> negated instead“. > > I was irritated and on the wrong track because I was absolutely sure that > self width is a number. > > Regards > > Max > > Am 16.07.2014 um 10:44 schrieb Alain Busser <alain.bus...@gmail.com>: > > That's where the Inspector comes in: > > To debug, it is good to insert a self width inspect so that the inspector > opens up and reveals what exactly the width is. OK, it is a number; then > open the browser and look at the number's methods; or in the finder, try 2 > . -2 in the examples... > > Pharo is excellent at debugging, that is why I choosed it for my Ontology > project, the browser shows welle what is a number, what kind of numbers > there are, and why a complex number is not a number... > > Alain > > > On Wed, Jul 16, 2014 at 2:59 AM, Verkoster Info <i...@derverkoster.de> > wrote: > >> It definitely is, >> >> >> >> thanks for all your answers… >> >> Regards >> >> Max >> >> Am 16.07.2014 um 00:56 schrieb Camille Teruel <camille.ter...@gmail.com >> >: >> >> I've been overtaken :) >> Isn't that an active mailing list ? >> >> >> On 16 juil. 2014, at 00:53, Camille Teruel <camille.ter...@gmail.com> >> wrote: >> >> Hi Max, >> >> Pharo doesn't have syntax for prefix operator like "-". >> The parser does accepts a "-" before literal numbers but it's not >> possible for arbitrary expressions. >> However you have the message #negated . >> >> negatedWidth >> ^ self width negated >> >> Cheers, >> Camille >> >> On 16 juil. 2014, at 00:16, Verkoster Info <i...@derverkoster.de> wrote: >> >> Hi, >> >> I am using latest Pharo 3.0 + vm. >> >> I have a method width with >> width >> >> ^ 115 * self ratio. >> in my understanding it returns a Number. >> >> When I try to create a method >> negatedWidth >> >> ^ - (self width). >> >> the UI tells me that only Numbers may be negated. I am not able to save >> the method. Am I on a wrong path or should that work and if how can I avoid >> the UI error message? >> >> Regards >> >> Max >> >> > >
