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[Caml-list] type problem with camlp4
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Date: 2003-01-07 (03:59)
From: Pietro Abate <Pietro.Abate@a...>
Subject: [Caml-list] type problem with camlp4
hi folks,

I have a problem expanding an <:expr<>> quotation.
the code snippet below raise this error
ocamlc -c -pp "camlp4o pa_extend.cmo q_MLast.cmo" -I
File "", line 19, characters 13-42:
This expression has type MLast.patt * ff but is here used with type
  MLast.patt * MLast.expr
how can I write the variable 'content' in the preprocessor step ?

It should be written down just like a string... is there any generic way 
to achive the same as I do with <:expr<$str:"ddd">> for strings with any
datatype ?

Of course immagine that the variable 'a' came from a more complex
function like a parser...


(*pp camlp4o pa_extend.cmo q_MLast.cmo *)

open Pcaml;;

type ff = 
    | A1
    | A2

let el = Grammar.Entry.create gram "el";;
        [[ "test"; n = LIST1 el SEP ";" ->
            <:expr< let $list:n$ in 1 >>
        [[ n = LIDENT ->
            let a = A1 in  (* <---- the problem is here!!! *)
            (<:patt<$lid:n$>>,<:expr<$a$>>) ]];

let a = test b ;;

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