[Cuis-dev] Bug or feature? #asInteger behaviour

[Hernan Wilkinson]

I think that renaming it to #findPositiveInteger is a good idea. Let's go
that way.

Cheers!
Hernan.

On Wed, Jan 6, 2021 at 10:27 AM Juan Vuletich <juan at jvuletich.org> wrote:

> On 1/6/2021 9:44 AM, Hernan Wilkinson via Cuis-dev wrote:
>
> Definitely a bug.
>
>
> I think whoever wrote that method was thinking #asPositiveInteger, which
> might have been a better name. Besides, I think that something like
> #findPositiveInteger would have been much better.
>
> Attached is a change set that fixes it with tests to verify the behavior
> of String>>asInteger
> I think we should think the behavior a little bit through... for example
> '---1' signals an error but '+++1' does not, or '.1' returns 1 but '0.1'
> returns 0...
>  I thinks this are rare cases and the solution is not what we would expect.
>
> Cheers!
> Hernan.
>
>
> What about the below? It gives what I think are the correct answers for
> '--1', '- 1', '---1' and '-+1'. To me, the correct answer is "seach for the
> first well formed integer number, ignoring all the rest'. It breaks your
> test, though.
>
> Anyway, looking at what the comment says, I'm more convinced that we'd
> leave as it was, but rename it as #findPositiveInteger.
>
> asInteger
>     "Answer the Integer created by interpreting the receiver as the string
> representation of an integer.  Answer nil if no digits, else find the first
> digit and then all consecutive digits after that"
>
>     | startPosition tail endPosition answer |
>     startPosition _ self findFirst: [:ch | ch isDigit].
>     startPosition = 0 ifTrue: [^ nil].
>     tail _ self copyFrom: startPosition to: self size.
>     endPosition _ tail findFirst: [:ch | ch isDigit not].
>     endPosition _ endPosition = 0
>         ifFalse: [endPosition-1]
>         ifTrue: [tail size].
>     answer _ Number readFrom: (tail copyFrom: 1 to: endPosition)
> readStream.
>     (startPosition > 1 and: [ (self at: startPosition-1) = $- ])
>         ifTrue: [ answer _ answer negated].
>     ^answer
>
> "
> '1796exportFixes-tkMX' asInteger
> '1848recentLogFile-sw'  asInteger
> 'donald' asInteger
> 'abc234def567' asInteger
> '-1' asInteger
> '--1' asInteger
> '---1' asInteger
> "
>
>
> On Wed, Jan 6, 2021 at 6:27 AM Philip Bernhart via Cuis-dev <
> cuis-dev at lists.cuis.st> wrote:
>
>> Hi,
>>
>> I just noticed that #asInteger has an unexpected behaviour.
>> That I thought is worth pointing out. Depending on what
>> someone could interpret as an integer (all unsigned numbers or
>> including negative numbers).
>>
>> I found out while looking at some Pharo code that:
>>
>> '-1' asInteger => -1 (in Pharo)
>> '-1' asInteger => 1 (in Cuis)
>>
>> 'Mötör-45heäd' asInteger => -45 (in Pharo)
>> 'Mötör-45heäd' asInteger => 45 (in Cuis)
>>
>> So the sign is lost.
>>
>> Was this intentional? Bug or feature?
>>
>>
>> Thanks,
>> Philip
>> --
>> --
>> Cuis-dev mailing list
>> Cuis-dev at lists.cuis.st
>> https://lists.cuis.st/mailman/listinfo/cuis-dev
>>
>
>
> --
>
> *Hernán Wilkinson Agile Software Development, Teaching & Coaching*
> *Phone: +54-011*-4893-2057
> *Twitter: @HernanWilkinson*
> *site: http://www.10Pines.com <http://www.10pines.com/>*
> Address: Alem 896, Floor 6, Buenos Aires, Argentina
>
>
> Thanks,
>
> --
> Juan Vuletichwww.cuis-smalltalk.orghttps://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Devhttps://github.com/jvuletichhttps://www.linkedin.com/in/juan-vuletich-75611b3
> @JuanVuletich
>
>

-- 

*Hernán WilkinsonAgile Software Development, Teaching & Coaching*
*Phone: +54-011*-4893-2057
*Twitter: @HernanWilkinson*
*site: http://www.10Pines.com <http://www.10pines.com/>*
Address: Alem 896, Floor 6, Buenos Aires, Argentina
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