[Interest] QFile::size() and QTextStream::pos()

[Elvis Stansvik]

2015-10-28 20:57 GMT+01:00 Igor Mironchik <igor.mironchik at gmail.com>:
> Hi,
>
> On 28.10.2015 22:50, Thiago Macieira wrote:
>>
>> On Wednesday 28 October 2015 22:37:06 Igor Mironchik wrote:
>>>
>>> Hi,
>>>
>>> Can I expect that values returned by QFile::size() and
>>> QTextStream::pos() are equal when stream at end?
>>
>> It should be, but...
>>
>>> Or pos() of text stream can be smaller then size of file because, for
>>> example, text stream uses 2 bytes for each character?
>>
>> The documentation says "Returns the device position corresponding to the
>> current position of the stream", so it should account for the codec
>> transformations.
>>
>> But since it's doing conversions along the way, there may be trouble.
>>
>> Why do you want to know this? Your question screams of the X-Y problem to
>> me.
>
>
> I want to calculate progress of file reading/parsing...
>
>>
>>> Do I understand right that QTextStream::skipWhiteSpace() skips '_' and
>>> '*' too?
>>
>> You can easily test this...
>>
>>> "bool QChar::isSpace() const
>>> Returns true if the character is a separator character (Separator_*
>>> categories or certain code points from Other_Control category);
>>> otherwise returns false."
>>
>> 002A;ASTERISK;Po;0;ON;;;;;N;;;;;
>> 002D;HYPHEN-MINUS;Pd;0;ES;;;;;N;;;;;
>>
>> Both have categories starting with P (Punctuation), so they're not
>> Separator
>> and they're not Other_Control.
>>
>> Why do you think '*' and '_' should be considered whitespace? They're not
>> even
>> blank...
>
>
> Because of this sentence:
>
> Separator_* categories or certain code points from Other_Control category
>
> And I don't know how to understand this, especially _* in the sentence...

The * is just a wildcard, so it means all categories that starts with
"Separator_".

Elvis

>
>
> --
> Best Regards,
> Igor Mironchik.
>
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