Ur/Web: tests/updateErr.ur annotate

Clarify necessity of 'effectful' in the manual

author	Adam Chlipala <adam@chlipala.net>
date	Tue, 13 Mar 2012 13:36:26 -0400
parents	7c6b6c3c7b79
children	abb0e95dcaa1

rev	line source
adamc@729	1 fun main () : transaction page =
adamc@729	2 s <- source "";
adamc@729	3 b <- Buffer.create;
adamc@729	4 txt <- source "";
adamc@729	5
adamc@729	6 return <xml><body onload={onError (fn xml => Buffer.write b (show xml));
adamc@729	7 onFail (fn s => alert ("FAIL! " ^ s))}>
adamc@729	8 <dyn signal={s <- signal s; return <xml>{[s]}</xml>}/><br/>
adamc@729	9 <dyn signal={s <- signal s; if s = "" then return <xml>Init</xml> else error <xml>Crapky</xml>}/><br/>
adamc@729	10 <dyn signal={s <- signal s; return <xml>"{[s]}"</xml>}/><br/>
adamc@729	11
adamc@729	12 <ctextbox source={txt}/> <button onclick={s' <- get txt; set s s'; set txt ""}/>
adamc@729	13
adamc@729	14 <hr/>
adamc@729	15
adamc@729	16 <dyn signal={Buffer.render b}/>
adamc@729	17 </body></xml>

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