Re: [Chicken-users] Nested hash-tables, and so on..

[.alyn.post.]

On Sun, Feb 09, 2014 at 03:29:09PM +0100, mfv wrote:
> Hi, 
> 
> I've been fooling around a bit with chicken, and now I am on towards a small
> project. I have a question regarding the performance of list and
> hash-tables.
> 
> I plan to use nested hash tables as a data structure e.g.
> 
> hash-table1
>           |
>           key1
>              |
>              hash-table2
>                        |
>                        key2
>                           |
>                           list/string/some data
> 
> Are there objections to such a nested hash table structure e.g. should one
> keep it as flat as possible and use multiple hash-table is parallel  in order 
> to maximize performance?
> 

In non-scheme languages, I use this technique a lot.  It's a poor
man's struct, and when you don't exactly know what problem you're
solving yet, that's precisely the data structure you need.

If you're worried about multiple hash table lookups, you can create
a composite key: pick a character/object that won't appear in key1..n,
and use it as a separator, joining and splitting your key to convert
it to/from it's composite.  I've rarely used this technique, compared
to the above above nested hash tables, so I suspect that nested
hashing will be adequate to solving the problem you have in mind.

I don't believe there is anything fundamentally wrong with your
approach.

-a
-- 
my personal website: http://c0redump.org/