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 <info@derverkoster.de> wrote:

It definitely is,

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thanks for all your answers��

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Regards

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Max

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Am 16.07.2014 um 00:56 schrieb Camille Teruel <camille.teruel@gmail.com>:

I've been overtaken :)
Isn't that an active mailing list ?��

On 16 juil. 2014, at 00:53, Camille Teruel <camille.teruel@gmail.com> wrote:

Hi Max,

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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 .

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negatedWidth
^ self width negated

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Cheers,

Camille

On 16 juil. 2014, at 00:16, Verkoster Info <info@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