annotate demo/buffer.ur @ 1619:15e0c935c91b

Catching integer divisions by zero
author Adam Chlipala <adam@chlipala.net>
date Sat, 03 Dec 2011 09:44:07 -0500
parents 755a71c99be5
children
rev   line source
adamc@697 1 datatype lines = End | Line of string * source lines
adamc@697 2
adamc@697 3 type t = { Head : source lines, Tail : source (source lines) }
adamc@697 4
adamc@697 5 val create =
adamc@697 6 head <- source End;
adamc@697 7 tail <- source head;
adamc@697 8 return {Head = head, Tail = tail}
adamc@697 9
adamc@697 10 fun renderL lines =
adamc@697 11 case lines of
adamc@697 12 End => <xml/>
adamc@697 13 | Line (line, linesS) => <xml>{[line]}<br/><dyn signal={renderS linesS}/></xml>
adamc@697 14
adamc@697 15 and renderS linesS =
adamc@697 16 lines <- signal linesS;
adamc@697 17 return (renderL lines)
adamc@697 18
adamc@697 19 fun render t = renderS t.Head
adamc@697 20
adamc@697 21 fun write t s =
adamc@697 22 oldTail <- get t.Tail;
adamc@697 23 newTail <- source End;
adamc@697 24 set oldTail (Line (s, newTail));
adamc@697 25 set t.Tail newTail