redef fun length do return root.length
+ # Iterator on the nodes of the rope, in forward postfix order
+ private fun postfix(from: Int): Postfix do return new Postfix.from(self, from)
+
+ # Iterator on the leaves of the rope, forward order
+ private fun leaves(from: Int): LeavesIterator do return new LeavesIterator(self, from)
+
+ # Iterator on the substrings from 0, in forward order
+ fun substrings: IndexedIterator[Text] do return new SubstringsIterator(self, 0)
+
+ # Iterator on the substrings, starting at position `from`, in forward order
+ fun substrings_from(from: Int): IndexedIterator[Text] do return new SubstringsIterator(self, from)
+
# Path to the Leaf for `position`
private fun node_at(position: Int): Path
do
var done = false
end
+# Simple Postfix iterator on the nodes of a Rope
+private class Postfix
+ super IndexedIterator[RopeNode]
+
+ # Target Rope to iterate on
+ var target: Rope
+
+ # Current position in Rope
+ var pos: Int
+
+ # Visited nodes
+ var stack = new List[IteratorElement]
+
+ init from(tgt: Rope, pos: Int)
+ do
+ self.target = tgt
+ self.pos = pos
+ if pos < 0 or pos >= tgt.length then return
+ var path = tgt.node_at(pos)
+ self.pos -= path.offset
+ for i in path.stack do
+ var item = new IteratorElement(i.node)
+ item.left = true
+ if i.right then item.right = true
+ stack.push item
+ end
+ var item = new IteratorElement(path.leaf)
+ item.done = true
+ stack.push item
+ end
+
+ redef fun item
+ do
+ assert is_ok
+ return stack.last.node
+ end
+
+ redef fun is_ok do return not stack.is_empty
+
+ redef fun index do return pos
+
+ redef fun next do
+ if stack.is_empty then return
+ if pos > target.length-1 then
+ stack.clear
+ return
+ end
+ var lst = stack.last
+ if lst.done then
+ if lst.node isa Leaf then
+ pos += lst.node.length
+ end
+ stack.pop
+ next
+ return
+ end
+ if not lst.left then
+ lst.left = true
+ var nod = lst.node
+ if nod isa Concat and nod.left != null then
+ stack.push(new IteratorElement(nod.left.as(not null)))
+ next
+ return
+ end
+ end
+ if not lst.right then
+ lst.right = true
+ var nod = lst.node
+ if nod isa Concat and nod.right != null then
+ stack.push(new IteratorElement(nod.right.as(not null)))
+ next
+ return
+ end
+ end
+ lst.done = true
+ end
+end
+
+# Iterates on the leaves (substrings) of the Rope
+class LeavesIterator
+ super IndexedIterator[Leaf]
+
+ private var nodes: Postfix
+
+ init(tgt: Rope, pos: Int)
+ do
+ nodes = tgt.postfix(pos)
+ end
+
+ redef fun is_ok do return nodes.is_ok
+
+ redef fun item
+ do
+ assert is_ok
+ return nodes.item.as(Leaf)
+ end
+
+ redef fun index do return nodes.index
+
+ redef fun next
+ do
+ while nodes.is_ok do
+ nodes.next
+ if nodes.is_ok and nodes.item isa Leaf then break
+ end
+ end
+end
+
+# Uses the leaves and calculates a new substring on each iteration
+class SubstringsIterator
+ super IndexedIterator[Text]
+
+ private var nodes: IndexedIterator[Leaf]
+
+ # Current position in Rope
+ var pos: Int
+
+ # Current substring, computed from the current Leaf and indexes
+ var substring: Text
+
+ init(tgt: Rope, pos: Int)
+ do
+ nodes = tgt.leaves(pos)
+ self.pos = pos
+ if pos < 0 or pos >= tgt.length then return
+ make_substring
+ end
+
+ # Compute the bounds of the current substring and makes the substring
+ private fun make_substring
+ do
+ substring = nodes.item.str
+ var min = 0
+ var length = substring.length
+ if nodes.index < pos then
+ min = pos - nodes.index
+ end
+ substring = substring.substring(min, length)
+ end
+
+ redef fun is_ok do return nodes.is_ok
+
+ redef fun item
+ do
+ assert is_ok
+ return substring
+ end
+
+ redef fun index do return pos
+
+ redef fun next
+ do
+ pos += substring.length
+ nodes.next
+ if nodes.is_ok then make_substring
+ end
+
+end
+