Source

oni / cf / cf_fmt_llscan.ml

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  Copyright (c) 2004-2010, James H. Woodyatt
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exception No_match

class virtual ['i] scanner z =
    object(self)
        val mutable next_: 'i Cf_seq.t = z
        
        method private virtual get: char
        
        method init = Scanf.Scanning.from_function (fun () -> self#get)
        method fini = next_
    end

let cscanf cf ef fmt rf z =
    let s = cf z in
    let ef0 _ x = ef s x in
    try
        let v = Scanf.kscanf s#init ef0 fmt rf in
        let z = s#fini in
        Some (v, z)
    with
    | No_match ->
        None

class lex_scanner z =
    object
        inherit [char] scanner z
                
        method private get =
            match Lazy.force next_ with
            | Cf_seq.Z ->
                raise End_of_file
            | Cf_seq.P (hd, tl) ->
                next_ <- tl;
                hd
    end

let scanf fmt rf z =
    let ef _ = raise No_match in
    cscanf (new lex_scanner) ef fmt rf z

(*--- $File$ ---*)