Version française
Home     About     Download     Resources     Contact us    
Browse thread
unix.select + camlp4
[ Home ] [ Index: by date | by threads ]
[ Search: ]

[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: -- (:)
From: Anastasia Gornostaeva <ermine@e...>
Subject: Re: [Caml-list] unix.select + camlp4
On Sun, Jul 01, 2007 at 09:37:46PM +0100, Jon Harrop wrote:

> > Is it possible to use camlp4-based parser with data which comes from
> > Unix.select input? Read a line, parse it, if a line was incomplete to parse
> > then save a state, continue.... How do to do it?
> 
> Bruno gave an excellent example of parsing strings using camlp4, posted on 
> 22/06/2007:
> 
> # open Camlp4.PreCast ;;
> # let expr = Gram.Entry.mk "expr" ;;
> val expr : '_a Camlp4.PreCast.Gram.Entry.t = <abstr>
> # EXTEND Gram
>      expr:
>        [ "add" LEFTA
>          [ e1 = expr; "+"; e2 = expr -> e1 +: e2
>          | e1 = expr; "-"; e2 = expr -> e1 -: e2 ]
>        | "mult" LEFTA
>          [ e1 = expr; "*"; e2 = expr -> e1 *: e2 ]
>        | "simple" NONA
>          [ n = INT -> Num(int_of_string n)
>          | "("; e = expr; ")" -> e ] ]
>        ;
>    END ;;
> - : unit = ()
> # Gram.parse expr Loc.ghost (Stream.of_string "1-2+3*4") ;;
> - : expr = Add (Sub (Num 1, Num 2), Mult (Num 3, Num 4))
> 
> If you can read a line from Unix.select then you should be able to feed it 
> into this.

I dont understand: Try:
1) It receives "1-2+3*" and parses it. 
2) Later it receives "4" and continues parsing.

I want to get non-blocking parser. How to implement?

ermine