X-Git-Url: http://nitlanguage.org

diff --git a/lib/core/text/ropes.nit b/lib/core/text/ropes.nit
index 10c1acf..f57b33d 100644
--- a/lib/core/text/ropes.nit
+++ b/lib/core/text/ropes.nit
@@ -221,23 +221,16 @@ private class Concat
 	end
 
 	redef fun copy_to_native(dest, n, src_offset, dest_offset) do
-		var subs = new RopeSubstrings.from(self, src_offset)
-		var st = src_offset - subs.pos
-		var off = dest_offset
-		while n > 0 do
-			var it = subs.item
-			if n > it.length then
-				var cplen = it.length - st
-				it._items.copy_to(dest, cplen, st, off)
-				off += cplen
-				n -= cplen
-			else
-				it._items.copy_to(dest, n, st, off)
-				n = 0
-			end
-			subs.next
-			st = 0
+		var l = _left
+		if src_offset < l.bytelen then
+			var lcopy = l.bytelen - src_offset
+			lcopy = if lcopy > n then n else lcopy
+			l.copy_to_native(dest, lcopy, src_offset, dest_offset)
+			dest_offset += lcopy
+			n -= lcopy
+			src_offset = 0
 		end
+		_right.copy_to_native(dest, n, src_offset, dest_offset)
 	end
 
 	# Returns a balanced version of `self`
@@ -670,7 +663,7 @@ private class RopeByteIterator
 	var ns: NativeString is noautoinit
 	# Substrings of the Rope
 	var subs: IndexedIterator[FlatString] is noautoinit
-	# Maximum position to iterate on (e.g. Rope.length)
+	# Maximum position to iterate on (e.g. Rope.bytelen)
 	var max: Int is noautoinit
 	# Position (char) in the Rope (0-indexed)
 	var pos: Int is noautoinit
@@ -680,7 +673,7 @@ private class RopeByteIterator
 		pns = pos - subs.index
 		self.pos = pos
 		ns = subs.item._items
-		max = root.length - 1
+		max = root.bytelen - 1
 	end
 
 	redef fun item do return ns[pns]
@@ -828,7 +821,7 @@ private class ReverseRopeSubstrings
 	redef fun next do
 		if pos < 0 then return
 		var curr = iter.prev
-		var currit = curr.node
+		var currit = curr.as(not null).node
 		while curr != null do
 			currit = curr.node
 			if not currit isa Concat then
@@ -935,14 +928,14 @@ private class RopeSubstrings
 	redef fun next do
 		pos += str.length
 		if pos > max then return
-		var it = iter.prev
+		var it = iter.prev.as(not null)
 		var rnod = it.node
 		loop
 			if not rnod isa Concat then
 				it.ldone = true
 				it.rdone = true
 				str = rnod.as(FlatString)
-				iter = it.as(not null)
+				iter = it
 				break
 			end
 			if not it.ldone then
@@ -954,7 +947,7 @@ private class RopeSubstrings
 				rnod = rnod._right
 				it = new RopeCharIteratorPiece(rnod, false, false, it)
 			else
-				it = it.prev
+				it = it.prev.as(not null)
 				rnod = it.node
 				continue
 			end
@@ -984,18 +977,45 @@ private class RopeBytes
 
 	redef type SELFTYPE: Concat
 
+	var cache: FlatString is noinit
+
+	var cache_start: Int = -1
+
+	var cache_end: Int = -1
+
 	redef fun [](i) do
-		var nod: String = target
+		assert i >= 0 and i < target._bytelen
+		var flps = _cache_start
+		if i >= flps and i <= _cache_end then
+			return _cache.bytes[i - flps]
+		end
+		var lf = get_leaf_at(i)
+		return lf.bytes[i - _cache_start]
+	end
+
+	fun get_leaf_at(pos: Int): FlatString do
+		var flps = _cache_start
+		if pos >= flps and pos <= _cache_end then
+			return _cache
+		end
+		var s: String = target
+		var st = pos
 		loop
-			if nod isa FlatString then return nod._items[i]
-			if not nod isa Concat then abort
-			var lft = nod._left
-			if lft.bytelen >= i then
-				nod = nod._right
+			if s isa FlatString then break
+			s = s.as(Concat)
+			var lft = s._left
+			var llen = lft.bytelen
+			if pos >= llen then
+				s = s._right
+				pos -= llen
 			else
-				nod = lft
+				s = lft
 			end
 		end
+		_cache_start = st - pos
+		_cache_end = st - pos + s.bytelen - 1
+		_cache = s
+		return s
 	end
 
 	redef fun iterator_from(i) do return new RopeByteIterator.from(target, i)