Ur/Web: demo/listFun.ur annotate

listFun uses length

author	Adam Chlipala <adamc@hcoop.net>
date	Tue, 21 Oct 2008 13:41:03 -0400
parents	ab3177746c78
children	e756d3a47726

rev	line source
adamc@398	1 open List
adamc@398	2
adamc@386	3 functor Make(M : sig
adamc@386	4 type t
adamc@398	5 val toString : t -> string
adamc@398	6 val fromString : string -> option t
adamc@386	7 end) = struct
adamc@398	8 fun toXml (ls : list M.t) =
adamc@398	9 case ls of
adamc@398	10 Nil => <xml>[]</xml>
adamc@398	11 \| Cons (x, ls') => <xml>{[M.toString x]} :: {toXml ls'}</xml>
adamc@398	12
adamc@398	13 fun console (ls : list M.t) = return <xml><body>
adamc@398	14 Current list: {toXml ls}<br/>
adamc@399	15 Length: {[length ls]}<br/>
adamc@399	16 <br/>
adamc@398	17
adamc@398	18 <form>
adamc@398	19 Add element: <textbox{#X}/> <submit action={cons ls}/>
adamc@398	20 </form>
adamc@398	21 </body></xml>
adamc@398	22
adamc@398	23 and cons (ls : list M.t) (r : {X : string}) =
adamc@398	24 case M.fromString r.X of
adamc@398	25 None => return <xml><body>Invalid string!</body></xml>
adamc@398	26 \| Some v => console (Cons (v, ls))
adamc@398	27
adamc@398	28 fun main () = console Nil
adamc@386	29 end

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