Re: [Caml-list] Operation complexity

[Karl Zilles <zilles@1969.ws>]

Zed Sereg wrote:
> Hello World, I have a obfuscating question, for whih I can found no answer.
>  
> I have to handle huge string arrays in a kind of database parsing.
> At the end, i have a code of the shape :
> let request_word s = ...
> val request_word : string -> string array list
>  
> let associate v =
>     let n = Array.length v in
>     let v' = array.make n (request_word v.(0)) in
>     for i = 1 to n-1 ledo
>         v'.(i) <- (request_word v.(i));
>     done;
>     v'
> ;;
>  
> val associate : string array -> string array list array = <fun>

Hi Zed,

Have you looked at Array.map?

let associate = Array.map request_word;;

>  
> Yeah, it 's obfuscating, but I had no time to find another solution.And 
> this is awfully slow... (In order to know, the computating time of each 
> request separately is around 2 secs. I waited 5 minutes for a call of 
> associate with a 3 elements vector.)

I have trouble believing that associate is your problem.  Time to fire 
up the profiler to find out where that time is coming from?

>  
> I would like to know if there is a way to do the same thing, without 
> replacing a value in v' at each iteration. Would it really be better to 
> switch the structure from an array to a temporary list, and after, 
> copying the list into an array with Array.of_list.

Your code looks ok to me.  I think your problem is elsewhere.

Karl

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