Re: Make many insertions in long string

Note, that the Rope data structure is also available in Core:
https://github.com/janestreet/core_kernel/blob/master/src/rope.mli

On Sun, Nov 29, 2015 at 11:18 AM, [email protected]
[ocaml_beginners] <[email protected]> wrote:

>
>
> Thank you for your feedback. It helped me a lot ! In reality, using
> String.concat is not that hard (see the relatively short&simple code
> below), you just have to be careful a little bit about the order of the
> operations.
>  I was amazed by the efficiency of that solution : it executes my initial
> computation in less than a second!
>
>
>   let adjacent_elements_pair_list l=
>         let rec sub_f=
>             (function (accu,a,rl)->match rl with
>             []->List.rev(accu)
>             |b::x->sub_f((a,b)::accu,b,x)
>             ) in
>         match l with
>         []->[]
>         |u::v->sub_f([],u,v);;
>
>   let interval s a b=String.sub s (a-1) (b-a+1);;
>
>
>   let insert_at_points s l=
>      let n=String.length s in
>      let temp1=(n,"")::(List.rev_append l [0,""]) in
>      let temp2=adjacent_elements_pair_list temp1 in
>      let temp3=List.rev_map (fun ((j2,w2),(j1,w1))->(interval s (j1+1)
> j2)^w2) temp2 in
>      String.concat "" temp3;;
>
>   let example= insert_at_points "123456789" [3,"aaa";6,"bb"];;
>
>
> 
>