RE: String algorithm

["Carlos Augusto Teixeira Mendes" <cmendes@...>]

Or you might put all your strings into a single table and use table.concat.

IIRC it already uses the algorithm that you are mentioning.

Regards,
Carlos Augusto.

> -----Original Message-----
> From: lua-bounces@bazar2.conectiva.com.br
> [mailto:lua-bounces@bazar2.conectiva.com.br]On Behalf Of Itterheim,
> Steffen
> Sent: Thursday, January 25, 2007 11:43 AM
> To: Lua list
> Subject: AW: String algorithm
>
>
> You might also be interested in the string buffer example:
> http://lua-users.org/wiki/SimpleStringBuffer
>
>
> -----Ursprüngliche Nachricht-----
> Von: lua-bounces@bazar2.conectiva.com.br
> [mailto:lua-bounces@bazar2.conectiva.com.br] Im Auftrag von Mark Meijer
> Gesendet: Donnerstag, 25. Januar 2007 14:26
> An: lua@bazar2.conectiva.com.br
> Betreff: String algorithm
>
> Hi all,
>
> I remember finding an algorithm on the lua wiki a couple of years
> ago, that dealt with reading a text file one line at a time (or
> one word at a time, in any case piece by piece) and concatenating
> all the pieces into a single string. The algorithm was meant to
> prevent numerous copying of the string in memory, which would
> occur using a straightforward approach such as the
> following:
>
> for line in file:lines() do
> mytext = mytext .. line;
> end
>
> The above approach would be unacceptably inefficient when dealing
> with large input files, because with each iteration the entire
> contents of the variable mytext would be duplicated into a new
> memory location.
>
> I've been trying to find the algorithm again (already 7 months
> ago, and now
> again) but for the life of me I can't find it anywhere. I don't
> remember exactly how it goes, but I believe it entails storing
> the string pieces into a table (possibly a regular array) and
> selectively concatenating some pieces, based on their size
> relative to other pieces in the table. The newly formed string
> would be placed back into the table. This process continues until
> only one string remains in the table, which represents the whole
> file read into that string.
>
> That's about as much as I remember of it. Plus, I found it
> briljant in its simplicity and in how it drastically reduced the
> effective amount of duplications needed (if I remember correctly,
> it would effectively duplicate the entire length of data only
> once or twice, but I could be wrong here).
> Obviously it was not simple enough for me to remember it :P but
> if any of you have any idea what I'm talking about, I'd really
> like to hear it.
>
> Thanks!
>
> Regards,
> Mark
>
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