Richard Jones wrote:
>   let devs = {{ map [xml] with
>     | <domain..>[<devices..>[<disk..>[<source dev=(Latin1 & s) ..>_]]]
>     | <domain..>[<devices..>[<disk..>[<source file=(Latin1 & s) ..>_]]] -> [s]
>     | _ -> [] }} in

The following should work:

   let l = {{ [xml] }} in
   let l = {{ map l with <domain..>l -> l | _ -> [] }} in
   let l = {{ map l with <devices..>l -> l | _ -> [] }} in
   let l = {{ map l with <disk..>l -> l | _ -> [] }} in
   let l = {{ map l with <source dev=(Latin1 & s) ..>_
                       | <source file=(Latin1 & s) ..>_-> s
                       | _ -> [] }} in
   ...

let () =
   let l = {{ [xml] }} in
   let l = {{ (((l.(<domain..>_)) / .(<devices..>_)) / .(<disk..>_)) / }} in
   let l = {{ map l with <source dev=(Latin1 & s) ..>_
                       | <source file=(Latin1 & s) ..>_ -> s
                       | _ -> [] }} in
   ..


This uses the constructions e/ and e.(t) as described in the manual.

That said, using OCamlDuce for this kind of XML data-extraction seems 
just crazy to me.


Cheers,

Alain