[Cuis-dev] fileout. proposed 2 new methods for strict file chunks reading

[Nicola Mingotti]

Hi Dave,

for me it is not a religious matter. You guys can decide whatever you wish
and we'll still be friends;)

I came from an academic background so I believe I should try
to convince my colleagues what I say has validity, opinions are not all 
the same,
permit me to insist a bit. There will not be a follow up to this, 
insistence ends here.

Monday i wanted to read some stupid lines from a log files
and I COULD NOT do it easily and CORRECTLY because the function 'upTo' 
has logical
issues related to undecidability of its output.

So, i had to:
1) detect the problem
2) rewrite the correct 'upTo' my self
=> A novice programmer can't do that, he take the sort path and stick 
with the bugous implementation.
=> sooner or later the program will brake

I tried to understand where this stuff come from, and i see it comes
from far away. See "Draft Smalltalk Ansi Smalltalk Standard pg. 280"
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiZsPmMutjzAhUKgP0HHdsOAyAQFnoECCQQAQ&url=https%3A%2F%2Fwiki.squeak.org%2Fsqueak%2Fuploads%2F172%2Fstandard_v1_9-indexed.pdf&usg=AOvVaw3BMiGjnp2vgwHcPe3e2_Ue

This is a problem. On the other side, it can be written on the Bible 
itself, but this function has
logical issues and this is undeniable. Now that I see it is also in the 
Standard it is not wise
to change the function 'upTo' but it is definitely worth to give programmers
the opportunity not to make things wrong providing a method they can 
trust: 'strictUpTo'.


bye
Nicola














On 10/20/21 03:10, David T. Lewis via Cuis-dev wrote:
> Hi Nicola,
>
> On Tue, Oct 19, 2021 at 03:32:08PM +0200, Nicola Mingotti via Cuis-dev wrote:
>> Hi Hernan,
>>
>> In all frankness, in I would wipe out the old 'upTo' because its
>> behavior is a bit "wild".
>>
> If you put a hundred programmers in a room, you will get a thousand
> opinions about things that are needed for programmers.
>
> The semantics of PositionableStream>>upTo: are clearly defined in the
> method comment. Implementing #strictUpTo: is a reasonable thing to do,
> but as Hernan has suggested it does not need to be in the base image.
>
> Dave
>
>
>> On the other side, I understand it may create problems in
>> retro-compatibility, that is why for
>> the moment i propose to add a new method which behaves a bit better.
>>
>> I hope this example explains the problem:
>> -------------------------------------------------------
>> s _ 'hello-1Ahello-2Ahel'.
>> '/tmp/test.txt' asFileEntry fileContents: s.
>>
>> st1 _ '/tmp/test.txt' asFileEntry readStream .
>>
>> st1 upTo: $A. " 'hello-1' "
>> st1 upTo: $A. " 'hello-2' "
>> st1 upTo: $A. " 'hel' "???????????????? "(*)"
>> ------------------------------------------------------
>> (*) You can't establish in any way if you actually found an "A"
>> terminated block or just hit the end of file
>> (*) If you hit the end of file you eat an incomplete record, this is
>> another problem, maybe another process
>> was going to end writing that record but you will never know.
>>
>> Maybe there is another method around that performs similarly to
>> 'strictUpTp', if there is I did not find it, sorry.
>>
>> IMHO, In a scale of importance from 0 to 10, this method, for a
>> programmer, >= 8.
>> I would definitely not put it into an external package, too much
>> fundamental.
>>
>> bye
>> Nicola
>>
>>
>> On 10/19/21 14:44, Hernan Wilkinson wrote:
>>> Hi Nicola!
>>> ??I was wondering, why are you suggesting adding them to the base? Is
>>> it not enough??to implement them as an extension in your package?
>>> ??Also, I think that any new functionality??should come with its
>>> corresponding tests to help the maintenance and understanding of the
>>> functionality.
>>>
>>> Cheers!
>>> Hernan.
>>>
>>>
>>> On Tue, Oct 19, 2021 at 7:04 AM Nicola Mingotti via Cuis-dev
>>> <cuis-dev at lists.cuis.st> wrote:
>>>
>>>     Hi Juan, guys,
>>>
>>>     I would like to add to Cuis the 2 methods i attach here. One is a
>>>     helper method.
>>>
>>>     -----------
>>>     StandardFileStream strictUpTo: delim.
>>>     -----------
>>>
>>>     Differently from 'upTo: delim' this method:
>>>     1. Does not return stuff if it does not find 'delim'.
>>>     2. Does not upgrade the position on the stream if does not find
>>>     'delim'.
>>>     3. If it finds 'delim' returns a chunk that includes it.
>>>
>>>     I am parsing log files at the moment, this is very much useful.
>>>
>>>     NOTE. Up to now I tested only on small files.
>>>
>>>     bye
>>>     Nicola
>>>
>>>
>>>
>>>
>>>     --
>>>     Cuis-dev mailing list
>>>     Cuis-dev at lists.cuis.st
>>>     https://lists.cuis.st/mailman/listinfo/cuis-dev
>>>
>>>
>>>
>>> -- 
>>> <https://10pines.com/>
>>>
>>>
>>>   Hern??n Wilkinson
>>>
>>>
>>>     Software Developer & Coach
>>>
>>> Alem 896, Floor 6, Buenos Aires, Argentina
>>>
>>> +54 11 6091 3125
>>>
>>> @HernanWilkinson
>>>
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