annotate tests/buffer.ur @ 2201:1091227f535a

Unnest properly in presence of kind polymorphism
author Adam Chlipala <adam@chlipala.net>
date Sun, 20 Dec 2015 13:41:35 -0500
parents 2197f0e24a9f
children
rev   line source
adamc@728 1 datatype lines = End | Line of string * source lines
adamc@728 2
adamc@728 3 type t = { Head : source lines, Tail : source (source lines) }
adamc@728 4
adamc@728 5 val create =
adamc@728 6 head <- source End;
adamc@728 7 tail <- source head;
adamc@728 8 return {Head = head, Tail = tail}
adamc@728 9
adamc@728 10 fun renderL lines =
adamc@728 11 case lines of
adamc@728 12 End => <xml/>
adamc@728 13 | Line (line, linesS) => <xml>{[line]}<br/><dyn signal={renderS linesS}/></xml>
adamc@728 14
adamc@728 15 and renderS linesS =
adamc@728 16 lines <- signal linesS;
adamc@728 17 return (renderL lines)
adamc@728 18
adamc@728 19 fun render t = renderS t.Head
adamc@728 20
adamc@728 21 fun write t s =
adamc@728 22 oldTail <- get t.Tail;
adamc@728 23 newTail <- source End;
adamc@728 24 set oldTail (Line (s, newTail));
adamc@728 25 set t.Tail newTail