Re: proposal: support empty string as separator for string_to_array

2009/7/25 Merlin Moncure <mmoncure@gmail.com>:
> On Fri, Jul 24, 2009 at 11:40 PM, Pavel Stehule<pavel.stehule@gmail.com> wrote:
>> Hello
>>
>> I have one idea, that should simplify string to char array
>> transformation. The base is idea: between every char is empty string,
>> so empty string is regular separator for string_to_array function.
>> This behave is inversion of array_to_string function behave:
>>
>> postgres=# select array_to_string(array['a','b','c'],'');
>>  array_to_string
>> -----------------
>>  abc
>> (1 row)
>>
>> postgres=# select string_to_array('abc','');
>>  string_to_array
>> -----------------
>>  {a,b,c}
>> (1 row)
>
> postgres=# select regexp_split_to_array('abc', '');
>  regexp_split_to_array
> -----------------------
>  {a,b,c}
> (1 row)
>
> :-)
>

I tested  implementation and it's about 30% faster than using regexp.

I could to thing, 30% is significant reason for implementation.

regards
Pavel Stehule


> merlin
>