On 12 August 2011 14:35, Nicolas Cellier
<nicolas.cellier.aka.nice at gmail.com> wrote:
> 2011/8/12 Frank Shearar <frank.shearar at gmail.com>:
>> I went and looked (rather belatedly, in hindsight) at the tests, and
>> indeed we explicitly support (as in there are tests documenting the
>> behaviour) the parsing of '1.' as a string representation of 1.0.
>>
>> My immediate issue is that this makes my work on Coral more
>> complicated, because in Pharo Number readFrom: '1.' returns 1 and
>> leaves '.' on the stream (just like it would for Number readFrom:
>> '1x').
>>
>> But it also means we have an ambiguity in our grammar: there's no way
>> to know whether in '1.' the dot belongs to the number literal, or
>> whether it terminates the statement.
>>
>> frank
>>
>
> Well, no, because we do not use Number class>>readFrom: in the Parser.

Fair enough:

    a := 1..
    a "=> 1, so '..' means 'end statement, end (empty) statement'."


But that means that we have a number parser that permits a grammar
that doesn't match the host language's grammar, right? To be precise,
SqNumberParser says "SqNumberParser is a NumberParser specialized in
reading Number with Squeak syntax." but actually accepts something
slightly different from Squeak syntax.

Again: if there's good reason for this, that's fine - that would just
mean I've been surprised. It just seems... odd.

For my personal needs, the right thing's probably to extend
PetitSmalltalk to parse numbers, instead of "calling out" to Number
class >> readFrom: to parse the numbers.

> Nicolas
>
>> On 12 August 2011 09:26, Nicolas Cellier
>> <nicolas.cellier.aka.nice at gmail.com> wrote:
>>> For the sake of it, I would say things are not worse than before I put
>>> my big nose in the code:
>>>
>>> http://lists.squeakfoundation.org/pipermail/squeak-dev/2006-April/103137.html
>>>
>>> Nicolas
>>>
>>> 2011/8/12 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>>>> This was changed in:
>>>>
>>>> The Trunk: Compiler-nice.125.mcz
>>>> The Trunk: Kernel-nice.404.mcz
>>>>
>>>> The rationale is that (Number readFrom: ) is a very poor way to report
>>>> a syntax error in the number.
>>>> SqNumberParser can do much better when invoked with ad hoc API.
>>>>
>>>> This release the necessity for Number>>readFrom: to strictly adhere to
>>>> Smalltalk syntax (which it did not since it also interprets infinity
>>>> and nan).
>>>>
>>>> Nicolas
>>>>
>>>> 2011/8/12 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
>>>>> Yes, in Squeak this behavior is obtained with the ExtendedNumberParser.
>>>>> You can read these floats for example:
>>>>>
>>>>> 1.
>>>>> 1.e+30
>>>>> .1
>>>>> -.1e+30
>>>>>
>>>>> Though, in Smalltalk source code, the SqNumberParser is used and you can't.
>>>>>
>>>>> Nicolas
>>>>>
>>>>> 2011/8/12 Frank Shearar <frank.shearar at gmail.com>:
>>>>>> Hi,
>>>>>>
>>>>>> While playing around, I've found that Number readFrom: '1.' returns
>>>>>> 1.0 ... I'd expected a 1.
>>>>>>
>>>>>> Is this expected behaviour?
>>>>>>
>>>>>> frank
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>>
>>
>>
>
>