[ruby-core:28500] Re: [Feature #905] Add String.new(fixnum) to preallocate large buffer

Hi,

2010/3/5 Hugh Sasse <[e-mail]>:
>> At first glance, the document explains the difference of destructive
>> and non-destructive concatenations, like String#+ and #<<.
>>
>> It is absolutely different topic from pre-allocation.
>
> It is related: the algorithm constructs large strings from smaller
> ones in an elegant way using a "tower of Hanoi", and if the top
> string concatenation gets bigger than the one below it, only then
> are they joined together.  Result is less copying and merging.


Ah, sorry.  I had to read all more carefully.

The algorithm itself is interesting, but I understand it is
just workaround to implement efficient string buffer by using
*immutable* strings (because Lua String seems always immutable).

But Ruby String is mutable.  Is it also more efficient with
*mutable* string than current direct concatenation?  I wonder
if the algorithm needs more memcpy than the current.

-- 
Yusuke ENDOH <[e-mail]>