00:09 <tehdeuce> I'm not sure that this is the greatest place to ask, but what would the best way to implement a sort of bi-directional hash table (that's probably not the right term). I have a bunch of pairs of values, and I want to be able to use either term to look up the other. I have a couple ideas of how I could do it, but I thought it might be a good idea to ask and make sure there isn't some better way to do it that I don't know of

00:16 <lucca> this problem appears a lot in databases;

00:16 <lucca> wanting multiple indexed columns into a table, for example

00:17 <lucca> optimality depends on usage... is it static data or will there be updates? do you need cursors? etc

00:17 <lucca> trees are a good approach

00:17 <lucca> multiple hashes can work

00:18 <tehdeuce> There will be updates, but I don't need cursors. How exactly could I use trees to do this?

00:19 <lucca> pick a primary key (not necessarily either of your two main things you want, but possibly)

00:19 <lucca> have a tree mapping that key to your records

00:19 <lucca> for each indexed column (direction of hashing in your original question)

00:20 <lucca> keep another tree mapping that value to a primary key in the main tree

00:20 <lucca> each time you add a record, drop it in the main tree and add nodes to the index trees as per its values

00:20 <lucca> similar for delete/modify

00:21 <tehdeuce> Ah. Thanks for the help.

00:21 <lucca> things get more interesting if you need to implement two-phase commits

00:21 <lucca> e.g. for a distributed transaction manager

00:21 <lucca> enjoy...

00:22 <tehdeuce> heh, I doubt I'll have the need for that any time soon

02:19 <mbishop> Hmm, so could JoCaml become the solution to concurrency in Ocaml? (and I do mean "the" solution)

02:24 <slacker403> yoooooo

02:24 <slacker403> looks like ocaml is getting more and more popular

03:55 <kelaouchi> rwmjones did you get mod_caml working ?

03:55 <kelaouchi> did you make a package ?

13:07 <_ke> hi

16:39 <jacobian_wrk> how do you load pcre from the interactive session?

16:39 <jacobian_wrk> I tried #load "pcre/pcre.cma";;

16:39 <jacobian_wrk> which works without error, yet there is no pcre module

16:40 <rwmjones> jacobian_wrk, what do you mean "yet there is no pcre module"?

16:40 <jacobian_wrk> # open Pcre;;

16:40 <jacobian_wrk> Unbound module Pcre

16:41 <rwmjones> ok, it's a path issue

16:41 <rwmjones> either do: ocaml -I +pcre

16:41 <rwmjones> or #directory "+pcre" before doing the #load

16:41 <rwmjones> $ ocaml -I +pcre

16:41 <rwmjones> Objective Caml version 3.09.3

16:41 <rwmjones> # #load "pcre.cma";;

16:41 <rwmjones> # open Pcre;;

16:41 <rwmjones> # regexp;;

16:41 <rwmjones> - : ?study:bool ->

16:41 <rwmjones> ?limit:int ->

16:41 <rwmjones> ?iflags:Pcre.icflag ->

16:41 <rwmjones> ?flags:Pcre.cflag list ->

16:41 <rwmjones> ?chtables:Pcre.chtables -> string -> Pcre.regexp

16:42 <rwmjones> = <fun>

16:42 <jacobian_wrk> awesome, thanks

16:47 <mbishop> or #use "topfind";;

18:32 <kelaouchi> rwmjones what about mod_caml ?

18:37 <rwmjones> kelaouchi, it's going to be a while before I can look at that. You're probably better off finding Joel Reymont.