On 16 juil. 2014, at 11:12, 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. You are right, the error message should be better. I opened a bug entry and submitted a slice with the new error message: "The '-' prefix works only for literal numbers (use #negated instead)". https://pharo.fogbugz.com/f/cases/13568/Better-error-message-when-using-prefix > 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 >>>>> >> >
