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 >>>> >
