Mercurial > urweb
view demo/listFun.ur @ 479:ffa18975e661
Broaden set of possible especializations
author | Adam Chlipala <adamc@hcoop.net> |
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date | Sat, 08 Nov 2008 14:42:52 -0500 |
parents | e756d3a47726 |
children | 7ef4b2911b09 |
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open List functor Make(M : sig type t val toString : t -> string val fromString : string -> option t end) = struct fun toXml (ls : list M.t) = case ls of Nil => <xml>[]</xml> | Cons (x, ls') => <xml>{[M.toString x]} :: {toXml ls'}</xml> fun console (ls : list M.t) = return <xml><body> Current list: {toXml ls}<br/> Reversed list: {toXml (rev ls)}<br/> Length: {[length ls]}<br/> <br/> <form> Add element: <textbox{#X}/> <submit action={cons ls}/> </form> </body></xml> and cons (ls : list M.t) (r : {X : string}) = case M.fromString r.X of None => return <xml><body>Invalid string!</body></xml> | Some v => console (Cons (v, ls)) fun main () = console Nil end