intrude import string
+# Used when searching for a particular node
+# Returns the path to the node from the root of the rope
+# Also, the node and the offset for seeked position in the rope
+private class Path
+ # Leaf found
+ var leaf: Leaf
+ # Offset in leaf
+ var offset: Int
+ # Stack of the nodes traversed, and the path used
+ var stack: List[PathElement]
+end
+
+# An element for a Path, has the concat node and whether or not
+# left or right child was visited.
+private class PathElement
+ # Visited node
+ var node: Concat
+ # Was the left child visited ?
+ var left = false
+ # Was the right child visited ?
+ var right = false
+end
+
# A node for a Rope
private abstract class RopeNode
# Length of the node
var length = 0
+
+ # Transforms the current node to a Leaf.
+ # This might be costly to invoke since this produces a FlatString concatenation.
+ # Can be used internally to limit the growth of the Rope when working with small leaves.
+ fun to_leaf: Leaf is abstract
end
# Node that represents a concatenation between two nodes (of any RopeNode type)
super RopeNode
# Left child of the node
- var _left: nullable RopeNode = null
+ var left: nullable RopeNode
# Right child of the node
- var _right: nullable RopeNode = null
-
- fun left: nullable RopeNode do return _left
- fun right: nullable RopeNode do return _right
+ var right: nullable RopeNode
- fun left=(l: RopeNode)
+ init(l: nullable RopeNode, r: nullable RopeNode)
do
- _left = l
- length = l.length
- if _right != null then length += _right.length
+ left = l
+ right = r
+ if l != null then length += l.length
+ if r != null then length += r.length
end
- fun right=(r: RopeNode)
+ redef fun to_leaf
do
- _right = r
- length = r.length
- if _left != null then length += _left.length
+ if left == null then
+ if right == null then return new StringLeaf("".as(FlatString))
+ return right.to_leaf
+ end
+ if right == null then return left.as(not null).to_leaf
+ return new StringLeaf((left.to_leaf.str.as(FlatString) + right.to_leaf.str.as(FlatString)).as(FlatString))
end
end
# Leaf of a Rope, contains a FlatString
-private class Leaf
+private abstract class Leaf
super RopeNode
# Encapsulated FlatString in the leaf node
- var str: FlatString
+ var str: FlatText
+
+end
+
+private class StringLeaf
+ super Leaf
init(val: FlatString) do
self.str = val
length = str.length
end
+ redef fun to_leaf do return self
end
# Basic structure, binary tree with a root node.
# Root node, entry point of a Rope.
private var root: RopeNode
+ # Cached version of self as a flat String
+ private var str_representation: nullable NativeString = null
+
+ # Empty Rope
+ init do from("")
+
+ # Creates a new Rope with `s` as root
+ init from(s: String) do
+ if s isa RopeString then root = s.root else root = new StringLeaf(s.as(FlatString))
+ end
+
+ private init from_root(r: RopeNode)
+ do
+ root = r
+ end
+
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
+ redef fun substrings 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)
+
+ # Iterator on the nodes of the rope, in backwards postfix order
+ private fun reverse_postfix(from: Int): ReversePostfix do return new ReversePostfix.from(self, from)
+
+ # Iterator on the leaves of the rope, backwards order
+ private fun reverse_leaves(from: Int): ReverseLeavesIterator do return new ReverseLeavesIterator(self,from)
+
+ # Iterator on the substrings, in reverse order
+ fun reverse_substrings: IndexedIterator[Text] do return new ReverseSubstringsIterator(self, length-1)
+
+ # Iterator on the substrings, in reverse order, starting iteration at position `from`
+ fun reverse_substrings_from(from: Int): IndexedIterator[Text] do return new ReverseSubstringsIterator(self, from)
+
+ redef fun output
+ do
+ for i in substrings do
+ i.output
+ end
+ end
+
+ redef fun to_cstring
+ do
+ if str_representation != null then return str_representation.as(not null)
+
+ var native_final_str = calloc_string(length + 1)
+
+ native_final_str[length] = '\0'
+
+ if self.length == 0 then
+ str_representation = native_final_str
+ return native_final_str
+ end
+
+ var offset = 0
+
+ for i in substrings do
+ var str = i.flatten
+ if str isa FlatString then str.items.copy_to(native_final_str, str.length, str.index_from, offset)
+ offset += i.length
+ end
+
+ str_representation = native_final_str
+
+ return native_final_str
+ end
+
+ # Path to the Leaf for `position`
+ private fun node_at(position: Int): Path
+ do
+ assert position >= 0 and position < length
+ return get_node_from(root.as(not null), 0, position, new List[PathElement])
+ end
+
+ # Builds the path to Leaf at position `seek_pos`
+ private fun get_node_from(node: RopeNode, curr_pos: Int, seek_pos: Int, stack: List[PathElement]): Path
+ do
+ assert curr_pos >= 0
+ if node isa Leaf then return new Path(node, seek_pos - curr_pos, stack)
+ node = node.as(Concat)
+
+ if node.left != null then
+ var next_pos = curr_pos + node.left.length
+ stack.add(new PathElement(node))
+ if next_pos > seek_pos then
+ stack.last.left = true
+ return get_node_from(node.left.as(not null), curr_pos, seek_pos, stack)
+ end
+ stack.last.right = true
+ return get_node_from(node.right.as(not null), next_pos, seek_pos, stack)
+ else
+ var vis = new PathElement(node)
+ vis.right = true
+ stack.add(vis)
+ return get_node_from(node.right.as(not null), curr_pos, seek_pos, stack)
+ end
+ end
+
+ redef fun ==(o)
+ do
+ if not o isa Text then return false
+ if o.length != self.length then return false
+ var oit = o.chars.iterator
+ for i in self.chars.iterator do
+ if i != oit.item then return false
+ oit.next
+ end
+ return true
+ end
end
# Rope that cannot be modified
redef fun to_s do return self
+ redef fun empty do return once new RopeString.from("")
+
+ redef var chars: SequenceRead[Char] = new RopeStringChars(self)
+
+ redef fun reversed
+ do
+ var ret = empty.as(RopeString)
+ for i in substrings do
+ ret = ret.prepend(i.reversed.to_s).as(RopeString)
+ end
+ return ret
+ end
+
+ redef fun to_upper
+ do
+ var ret = empty
+ for i in substrings do
+ ret += i.to_upper
+ end
+ return ret
+ end
+
+ redef fun to_lower
+ do
+ var ret = empty
+ for i in substrings do
+ ret += i.to_lower
+ end
+ return ret
+ end
+
+ redef fun +(o) do return insert_at(o.to_s, length)
+
+ redef fun *(n)
+ do
+ var ret = new RopeString.from("")
+ for i in [0..n[ do
+ ret = (ret + self).as(RopeString)
+ end
+ return ret
+ end
+
+ # Inserts a String `str` at position `pos`
+ redef fun insert_at(str, pos)
+ do
+ if str.length == 0 then return self
+ if self.length == 0 then return new RopeString.from(str)
+
+ assert pos >= 0 and pos <= length
+
+ if pos == length then return append(str).as(RopeString)
+
+ var path = node_at(pos)
+
+ var last_concat: Concat
+
+ if path.offset == 0 then
+ if str isa FlatString then
+ last_concat = new Concat(new StringLeaf(str), path.leaf)
+ else
+ last_concat = new Concat(str.as(RopeString).root, path.leaf)
+ end
+ else if path.offset == path.leaf.length then
+ if str isa FlatString then
+ last_concat = new Concat(path.leaf, new StringLeaf(str))
+ else
+ last_concat = new Concat(path.leaf, str.as(RopeString).root)
+ end
+ else
+ var s = path.leaf.str
+ var l_half = s.substring(0, s.length - path.offset)
+ var r_half = s.substring_from(s.length - path.offset)
+ var cct: Concat
+ var ll = new StringLeaf(l_half.as(FlatString))
+ if str isa FlatString then
+ cct = new Concat(ll, new StringLeaf(str))
+ else
+ cct = new Concat(ll, str.as(RopeString).root)
+ end
+ last_concat = new Concat(cct, new StringLeaf(r_half.as(FlatString)))
+ end
+
+ for i in path.stack.reverse_iterator do
+ if i.left then
+ last_concat = new Concat(last_concat, i.node.right)
+ else
+ last_concat = new Concat(i.node.left, last_concat)
+ end
+ end
+
+ return new RopeString.from_root(last_concat)
+ end
+
+ # Adds `s` at the beginning of self
+ redef fun prepend(s) do return insert_at(s, 0)
+
+ # Adds `s` at the end of self
+ redef fun append(s)
+ do
+ if self.is_empty then return s
+ return new RopeString.from_root(append_to_path(root,s))
+ end
+
+ # Builds a new path from root to the rightmost node with s appended
+ private fun append_to_path(node: RopeNode, s: String): RopeNode
+ do
+ var cct: Concat
+ if node isa Leaf then
+ if s isa FlatString then
+ cct = new Concat(node, new StringLeaf(s))
+ else
+ cct = new Concat(node, s.as(RopeString).root)
+ end
+ else
+ var n = node.as(Concat)
+ var right = n.right
+ var lft = n.left.as(not null)
+ if right == null then
+ if s isa FlatString then
+ cct = new Concat(lft, new StringLeaf(s))
+ else
+ cct = new Concat(lft, s.as(RopeString).root)
+ end
+ else
+ cct = new Concat(lft, append_to_path(right, s))
+ end
+ end
+ return cct
+ end
+
+ # O(log(n))
+ #
+ # var rope = new RopeString.from("abcd")
+ # assert rope.substring(1, 2) == "bc"
+ # assert rope.substring(-1, 2) == "a"
+ # assert rope.substring(1, 0) == ""
+ # assert rope.substring(2, 5) == "cd"
+ #
+ redef fun substring(pos, len)
+ do
+ if pos < 0 then
+ len += pos
+ pos = 0
+ end
+
+ if pos + len > length then len = length - pos
+
+ if len <= 0 then return new RopeString.from("")
+
+ var path = node_at(pos)
+
+ var lf = path.leaf
+ var offset = path.offset
+
+ if path.leaf.str.length - offset > len then lf = new StringLeaf(lf.str.substring(offset,len).as(FlatString)) else lf = new StringLeaf(lf.str.substring_from(offset).as(FlatString))
+
+ var nod: RopeNode = lf
+
+ for i in path.stack.reverse_iterator do
+ if i.right then continue
+ nod = new Concat(nod, i.node.right)
+ end
+
+ var ret = new RopeString
+ ret.root = nod
+
+ path = ret.node_at(len-1)
+
+ offset = path.offset
+ nod = new StringLeaf(path.leaf.str.substring(0, offset+1).as(FlatString))
+
+ for i in path.stack.reverse_iterator do
+ if i.left then continue
+ nod = new Concat(i.node.left, nod)
+ end
+
+ ret.root = nod
+
+ return ret
+ end
+end
+
+redef class FlatString
+
+ redef fun append(s) do return (new RopeString.from(self)) + s
+
+ redef fun prepend(s) do return (new RopeString.from(self)).prepend(s)
+
+ redef fun insert_at(s, pos)
+ do
+ if pos == 0 then return prepend(s)
+ if pos == length then return append(s)
+
+ var l = substring(0,pos)
+ var r = substring_from(pos)
+ var ret: String = new RopeString.from(l)
+ ret += s
+ return ret + r
+ end
+
+end
+
+private class RopeStringChars
+ super SequenceRead[Char]
+
+ var tgt: Rope
+
+ redef fun [](pos)
+ do
+ assert pos < tgt.length
+ var path = tgt.node_at(pos)
+ return path.leaf.str.chars[path.offset]
+ end
+
+ redef fun iterator do return iterator_from(0)
+
+ redef fun iterator_from(pos) do return new RopeCharIterator(tgt, pos)
+
+ redef fun reverse_iterator do return reverse_iterator_from(tgt.length-1)
+
+ redef fun reverse_iterator_from(pos) do return new ReverseRopeCharIterator(tgt, pos)
+end
+
+# Used to iterate on a Rope
+private class IteratorElement
+
+ init(e: RopeNode)
+ do
+ if e isa Leaf then
+ left = true
+ right = true
+ end
+ node = e
+ end
+
+ # The node being visited
+ var node: RopeNode
+ # If the node has a left child, was it visited ?
+ var left = false
+ # If the node has a right child, was it visited ?
+ var right = false
+ # Was the current node visited ?
+ 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
+
+class RopeCharIterator
+ super IndexedIterator[Char]
+
+ var substrings: IndexedIterator[Text]
+
+ var pos: Int
+
+ var max: Int
+
+ var substr_iter: IndexedIterator[Char]
+
+ init(tgt: Rope, from: Int)
+ do
+ substrings = tgt.substrings_from(from)
+ max = tgt.length - 1
+ if not substrings.is_ok then
+ pos = tgt.length
+ return
+ end
+ pos = from
+ substr_iter = substrings.item.chars.iterator
+ end
+
+ redef fun item do return substr_iter.item
+
+ redef fun is_ok do return pos <= max
+
+ redef fun index do return pos
+
+ redef fun next
+ do
+ pos += 1
+ if substr_iter.is_ok then
+ substr_iter.next
+ end
+ if not substr_iter.is_ok then
+ substrings.next
+ if substrings.is_ok then
+ substr_iter = substrings.item.chars.iterator
+ end
+ end
+ end
+end
+
+private class ReversePostfix
+ super IndexedIterator[RopeNode]
+
+ var target: Rope
+
+ var pos: Int
+
+ var min = 0
+
+ var stack = new List[IteratorElement]
+
+ init from(tgt: Rope, pos: Int)
+ do
+ self.pos = pos
+ target = tgt
+ 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 elemt = new IteratorElement(i.node)
+ elemt.right = true
+ if i.left then
+ elemt.left = true
+ end
+ stack.push elemt
+ end
+ stack.push(new IteratorElement(path.leaf))
+ stack.last.done = true
+ 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 < min then
+ stack.clear
+ return
+ end
+ var lst = stack.last
+ if lst.done then
+ stack.pop
+ next
+ return
+ end
+ if not lst.right then
+ var nod = lst.node.as(Concat)
+ var rgt = nod.right
+ lst.right = true
+ if rgt != null then
+ stack.push(new IteratorElement(rgt))
+ next
+ return
+ end
+ end
+ if not lst.left then
+ var nod = lst.node.as(Concat)
+ var lft = nod.left
+ lst.left = true
+ if lft != null then
+ stack.push(new IteratorElement(lft))
+ next
+ return
+ end
+ end
+ if lst.node isa Leaf then pos -= lst.node.length
+ lst.done = true
+ end
+end
+
+private class ReverseLeavesIterator
+ super IndexedIterator[Leaf]
+
+ var nodes: ReversePostfix
+
+ init(tgt: Rope, from: Int)
+ do
+ nodes = tgt.reverse_postfix(from)
+ 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 next do
+ while nodes.is_ok do
+ nodes.next
+ if nodes.is_ok then if nodes.item isa Leaf then break
+ end
+ end
+
+ redef fun index do return nodes.index
+
+end
+
+private class ReverseSubstringsIterator
+ super IndexedIterator[Text]
+
+ var leaves: ReverseLeavesIterator
+
+ var pos: Int
+
+ var str: Text
+
+ init(tgt: Rope, from: Int)
+ do
+ leaves = tgt.reverse_leaves(from)
+ pos = from
+ if not leaves.is_ok then return
+ str = leaves.item.str
+ make_substring
+ end
+
+ fun make_substring
+ do
+ if pos >= (leaves.index + str.length - 1) then return
+ str = str.substring(0, (pos - leaves.index + 1))
+ end
+
+ redef fun is_ok do return leaves.is_ok
+
+ redef fun item do
+ assert is_ok
+ return str
+ end
+
+ redef fun index do return pos
+
+ redef fun next do
+ pos -= str.length
+ leaves.next
+ if not leaves.is_ok then return
+ str = leaves.item.str
+ make_substring
+ end
+end
+
+private class ReverseRopeCharIterator
+ super IndexedIterator[Char]
+
+ var substrs: IndexedIterator[Text]
+
+ var pos: Int
+
+ var subiter: IndexedIterator[Char]
+
+ init(tgt: Rope, from: Int)
+ do
+ substrs = tgt.reverse_substrings_from(from)
+ if not substrs.is_ok then
+ pos = -1
+ return
+ end
+ subiter = substrs.item.chars.reverse_iterator
+ pos = from
+ end
+
+ redef fun is_ok do return pos >= 0
+
+ redef fun item do
+ assert is_ok
+ return subiter.item
+ end
+
+ redef fun index do return pos
+
+ redef fun next do
+ pos -= 1
+ if subiter.is_ok then subiter.next
+ if not subiter.is_ok then
+ if substrs.is_ok then substrs.next
+ if substrs.is_ok then subiter = substrs.item.chars.reverse_iterator
+ end
+ end
end
nitlanguage / nit.git / blobdiff