On Thu, Aug 7, 2014 at 9:05 AM, Levente Uzonyi <leves at elte.hu> wrote:

> On Wed, 6 Aug 2014, Eliot Miranda wrote:
>
>  Hi Levente,
>>
>> On Wed, Aug 6, 2014 at 11:43 AM, Levente Uzonyi <leves at elte.hu> wrote:
>>       On Wed, 6 Aug 2014, Eliot Miranda wrote:
>>
>>             Hi All,
>>                 Squeak trunk also suffers from the Float parsed as a
>> Fraction bug:
>>
>>             1e-8 class Fraction
>>             1.0e8 class Float
>>
>>
>> I'm not entirely sure about it being a bug. I've checked Squeak 3.8
>> (pre-SqNumberParser), and it also parsed that literal as a Fraction. If I
>> want a Float, I can be explicit and use 1.0e-8.
>>
>>
>> IMO it very much *is* a bug.  Smalltalk-80 has never supported Fraction
>> literals.  They're always written as division expressions.  Fraction
>> answers false to isLiteral.  Just because it worked that way
>> doesn't mean it was right.  I suspect no one noticed.  Allowing Fraction
>> literals feels like a big change to me.
>>
>
> It's more like undefined behavior than a bug IMHO, though the lack of
> #isLiteral makes me think that the Fractions are not intentional.
> Interesting how Nicolas's SqNumberParser behaves the same way as the
> previous number parser in this case.
>
>
>
>>       I made a modified version of Fraction >> #printOn:base: which
>> outputs the literal format if possible. The change "fixes" the debugger
>> (note that itw was way less broken in Squeak than in Pharo
>>       anyway).
>>       The only drawback I found is that some fractions become a bit more
>> "complex" when printed, e.g. 3/4 => 75e-2
>>
>>
>> OK, but is this the right fix?  What does everybody think?  Keep the
>> language unchanged or add Fraction literals and add another incompatibility
>> with other dialects?
>>
>
> I don't think that anyone ever used this "feature" before, so doing what
> other dialects do is probably the best way to resolve this.


Agreed.  Smalltalk-80 v2 had no literal fractions.  ObjectWorks and
VisualWorks have never had literal fractions.  I can't speak for other
dialects, but I'm fairly sure none of the Smalltalk/V, Team/V lineage had
literal Fractions either.

If Fractions are literals
>> - what is the semantics of 1/0 (easy, it is not a literal, but needs to
>> be stated)?
>> - what is [1/0.1] on: ZeroDivide do: [:ex| #error] ?  Is it 10.0 or
>> #error, i.e. is 1/0.1 10.0 or 1 / 0 followed by the Integer 1?
>>
>
> I did not propose to make all fractions literals. My implementation simply
> prints decimal fractions with the exponent notation, e.g. 3/4 is printed as
> 75-e2, but 2/3 is still printed as (2/3).
>
>
> Levente
>
>
>
>>       Levente
>>             --
>>             eek! Eliot
>>
>> --
>> best,Eliot
>>
>>
>
>
>


-- 
best,
Eliot
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