1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/Tools/WWW_Find/mime.ML	Fri Nov 20 18:36:44 2009 +1100
     1.3 @@ -0,0 +1,56 @@
     1.4 +(*  Title:      mime_types.ML
     1.5 +    Author:     Timothy Bourke, NICTA
     1.6 +
     1.7 +Rudimentary support for mime_types.
     1.8 +*)
     1.9 +
    1.10 +signature MIME =
    1.11 +sig
    1.12 +  datatype t = Type of {
    1.13 +      main : string,
    1.14 +      sub : string, 
    1.15 +      params : (string * string) list
    1.16 +    }
    1.17 +
    1.18 +  val plain : t
    1.19 +  val html : t
    1.20 +  
    1.21 +  val parse_type : string -> t option
    1.22 +  val show_type : t -> string
    1.23 +end;
    1.24 +
    1.25 +structure Mime: MIME =
    1.26 +struct
    1.27 +
    1.28 +datatype t = Type of {
    1.29 +    main : string,
    1.30 +    sub : string, 
    1.31 +    params : (string * string) list
    1.32 +  };
    1.33 +
    1.34 +val strip =
    1.35 +  Substring.dropl Char.isSpace
    1.36 +  #> Substring.dropr Char.isSpace;
    1.37 +
    1.38 +val split_fields =
    1.39 +  Substring.splitl (fn c => c <> #"=")
    1.40 +  #> apsnd (Substring.triml 1)
    1.41 +  #> pairself (Substring.string o strip);
    1.42 +
    1.43 +fun show_param (n, v) = concat ["; ", n, "=", v];
    1.44 +
    1.45 +fun show_type (Type {main, sub, params}) =
    1.46 +      concat ([main, "/", sub] @ map show_param params);
    1.47 +
    1.48 +fun parse_type s =
    1.49 +  (case Substring.fields (Char.contains "/;") (Substring.full s) of
    1.50 +     t::s::ps => SOME (Type { main = (Substring.string o strip) t,
    1.51 +                              sub = (Substring.string o strip) s,
    1.52 +                              params = map split_fields ps })
    1.53 +   | _ => NONE);
    1.54 +
    1.55 +val plain = the (parse_type "text/plain; charset=utf-8");
    1.56 +val html = the (parse_type "text/html; charset=utf-8");
    1.57 +
    1.58 +end;
    1.59 +