[Chicken-users] Nested hash-tables, and so on..
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? Regards, mfv ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] Nested hash-tables, and so on..
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/ ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] Nested hash-tables, and so on..
On Feb 9, 2014, at 11:12 AM, .alyn.post. alyn.p...@lodockikumazvati.org wrote: 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. Any Scheme object can be hashed w/ the SRFI 69 equal?-hash function. So a composite key represented as a pair/list, vector, or record is feasible. I don't believe there is anything fundamentally wrong with your approach. -a -- my personal website: http://c0redump.org/ ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] Nested hash-tables, and so on..
Hi folks, thanks for the comments and suggestions. I will go forward with nested hash-tables then and have a look at composite keys. (= Cheers! ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
