Re: patch: to_string, to_array functions

2010/7/21 Robert Haas <robertmhaas(at)gmail(dot)com>:
> On Wed, Jul 21, 2010 at 2:25 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
>> 2010/7/21 Robert Haas <robertmhaas(at)gmail(dot)com>:
>>> On Wed, Jul 21, 2010 at 1:48 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
>>>> 2010/7/21 Robert Haas <robertmhaas(at)gmail(dot)com>:
>>>>> On Wed, Jul 21, 2010 at 12:08 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
>>>>>>>> I am thinking so we have to do decision about string_to_array and
>>>>>>>> array_to_string deprecation first. If these function will be
>>>>>>>> deprecated, then we can use a similar names (and probably we should to
>>>>>>>> use a similar names) - so text_to_array or array_to_string can be
>>>>>>>> acceptable. If not, then this discus is needless - then to_string and
>>>>>>>> to_array have to be maximally in contrib - stringfunc is good idea -
>>>>>>>> and maybe we don't need thinking about new names.
>>>>>>>
>>>>>>> Well, -1 from me for deprecating string_to_array and array_to_string.
>>>>>>>
>>>>>>> I am not in favor of the names to_string and to_array even if we put
>>>>>>> them in contrib, though.  The problem with string_to_array and
>>>>>>> array_to_string is that they aren't descriptive enough, and
>>>>>>> to_string/to_array is even less so.
>>>>>>
>>>>>> I am not a English native speaker, so I have a different feeling.
>>>>>> These functions do array_serialisation and array_deseralisation, but
>>>>>> this names are too long. I have not idea about better names - it is
>>>>>> descriptive well (for me) text->array, array->text - and these names
>>>>>> shows very cleanly symmetry between functions. I have to repeat - it
>>>>>> is very clean for not native speaker.
>>>>>
>>>>> Well, the problem is that array_to_string(), for example, tells you
>>>>> that an array is being converted to a string, but not how.  And
>>>>> to_string() tells you that you're getting a string, but it doesn't
>>>>> tell you either what you're getting it from or how you're getting it.
>>>>> We already have a function to_char() which can be used to format a
>>>>> whole bunch of different types as strings; I can't see adding a new
>>>>> function with almost the same name that does something completely
>>>>> different.
>>>>>
>>>>> array_split() and array_join(), following Perl?  array_implode() and
>>>>> array_explode(), along the lines suggested by Brendan?
>>>>
>>>> I have a problem with array_split - because there string is split. I
>>>> looked on net - and languages usually uses a "split" or "join". split
>>>> is method of str class in Java. So when I am following Perl, I feel
>>>> better with  just only "split" and "join", but "join" is keyword :( -
>>>> step back, maybe string_split X array_join ?
>>>>
>>>> select string_split('1,2,3,4',',');
>>>> select array_join(array[1,2,3,4],',');
>>>>
>>>> so my preferences:
>>>>
>>>> 1. split, join - I checked - we are able to create "join" function
>>>> 2. split, array_join - when only "join" can be a problem
>>>> 3. string_split, array_join - there are not clean symmetry, but it
>>>> respect wide used a semantics - string.split, array.join
>>>> 4. explode, implode
>>>> 5. array_explode, array_implode
>>>> -- I cannot to like array_split - it is contradiction for me.
>>>
>>> Well, I guess I prefer my suggestion to any of those (I know... what a
>>> surprise), but I think I could live with #3, #4, or #5.  It's hard for
>>> me to imagine that we really want to create a function called just
>>> join(), given the other meanings that JOIN already has in SQL.
>>
>> it hasn't any relation to SQL language - but I don't expect so some
>> like this can be accepted by Tom :). So for this moment we are in
>> agreement on #3, #4, #5. I think, we can wait one or two days for
>> opinions of others - and than I'll fix patch. ok?
>
> Yeah, I'd like some more votes, too.  Aside from what I suggested
> (array_join/array_split), I think my favorite is your #5.
>

ok

#5 - it is absolutely out of me - explode, implode are used in Czech
only with relation to bombs. In this moment I have a problem to decide
what is related to string_to_array and array_to_string - it is nothing
against to your opinion, just it means, so it hasn't any meaning for
me - and probably for lot of foreign developers. But I found on net,
that people use this names.

> We might also want to put some work into documentating the differences
> between the old and new functions clearly.
>

sure

Pavel

> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise Postgres Company
>