# A rope is a kind of string but instead of being flat, it relies on a binary tree structure to store data.
module ropes
-import file
intrude import string
-# Structure, tuple containing a LeafNode and an Int
-# Used for methods like [] or has/has_only
-private class TupleLeafNodePos
- private var curr_node: LeafNode
- private var corrected_pos: Int
- private var visit_stack: List[TupleVisitNode]
+# 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
-# Abstract class, represents all the services offered by both mutable and immutable ropes
-abstract class Rope
- super Comparable
- super StringCapable
-
- # Cached version of self as a flat String
- private var str_representation: nullable String = null
-
- redef type OTHER: Rope
+# 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
- # The first node of the hierarchy
- private var parent_node: RopeNode
+# A node for a Rope
+private abstract class RopeNode
+ # Length of the node
+ var length = 0
+end
- # Needed by the compiler to avoid producing an error with constructors in subclasses
- init do
- self.parent_node = new ConcatNode
- end
+# Node that represents a concatenation between two nodes (of any RopeNode type)
+private class Concat
+ super RopeNode
- # Initializes a new Rope with a text embedded in directly
- init with_string(str: String) do
- self.parent_node = new ConcatNode
- parent_node.as(ConcatNode).right_child = new LeafNode(str)
- parent_node.as(ConcatNode).update_data
- end
+ # Left child of the node
+ var _left: nullable RopeNode = null
+ # Right child of the node
+ var _right: nullable RopeNode = null
- # Returns a view on the rope
- fun chars: SequenceRead[Char]
- do
- return new CharRopeView(self)
- end
+ fun left: nullable RopeNode do return _left
+ fun right: nullable RopeNode do return _right
- # Gets the total length of the Rope
- fun length: Int
+ fun left=(l: RopeNode)
do
- return parent_node.length
+ _left = l
+ length = l.length
+ if _right != null then length += _right.length
end
- # Returns a flat version of self
- redef fun to_s
+ fun right=(r: RopeNode)
do
- if self.str_representation == null then flatten
- return str_representation.as(not null)
+ _right = r
+ length = r.length
+ if _left != null then length += _left.length
end
+end
- # Stores a flat version of self in cache
- private fun flatten: FlatString
- do
- var native_final_str = calloc_string(length + 1)
-
- native_final_str[length] = '\0'
-
- var offset = 0
-
- var iter = new DFSRopeLeafIterator(self)
-
- while iter.is_ok do
- iter.item.value.as(FlatString).items.copy_to(native_final_str, iter.item.value.length, 0, offset)
- offset += iter.item.value.length
- iter.next
- end
+# Leaf of a Rope, contains a FlatString
+private class Leaf
+ super RopeNode
- return native_final_str.to_s_with_length(length)
- end
+ # Encapsulated FlatString in the leaf node
+ var str: FlatString
- # Gets a node containing the substring to seek the char at the require position
- private fun get_node_for_pos(position: Int): TupleLeafNodePos
- do
- assert position >= 0 and position < self.length
-
- var curr_node: nullable RopeNode = parent_node
-
- var visit_stack = new List[TupleVisitNode]
-
- var curr_visit_tuple: TupleVisitNode
-
- loop
- if curr_node isa ConcatNode then
- curr_visit_tuple = new TupleVisitNode(curr_node)
- if curr_node.left_child != null and position < curr_node.left_child.length then
- curr_visit_tuple.left_visited = true
- curr_node = curr_node.left_child
- else if curr_node.right_child != null then
- curr_visit_tuple.left_visited = true
- curr_visit_tuple.right_visited = true
- if curr_node.left_child != null then position -= curr_node.left_child.length
- curr_node = curr_node.right_child
- else
- print "Fatal Error"
- abort
- end
- visit_stack.push(curr_visit_tuple)
- else if curr_node isa LeafNode then
- return new TupleLeafNodePos(curr_node, position, visit_stack)
- end
- end
+ init(val: FlatString) do
+ self.str = val
+ length = str.length
end
- # Concats two ropes and returns a new one
- fun +(other: Rope): Rope do
- var new_rope = new BufferRope
+end
- var first_iter = new DFSRopeLeafIterator(self)
+# Basic structure, binary tree with a root node.
+#
+# Also shared services by subsequent implementations.
+abstract class Rope
+ super Text
- while first_iter.is_ok do
- new_rope.append(first_iter.item.value)
- first_iter.next
- end
+ # Root node, entry point of a Rope.
+ private var root: RopeNode
- var second_iter = new DFSRopeLeafIterator(other)
+ # Cached version of self as a flat String
+ private var str_representation: nullable NativeString = null
- while second_iter.is_ok do
- new_rope.append(second_iter.item.value)
- second_iter.next
- end
+ # Empty Rope
+ init do from("")
- return new_rope
+ # Creates a new Rope with `s` as root
+ init from(s: String) do
+ if s isa RopeString then root = s.root else root = new Leaf(s.as(FlatString))
end
- # Returns a copy of several ropes concatenated
- #
- # Is equivalent to a chain of + operations
- # Except this one is optimized for performance
- fun multi_concat(ropes: Rope...): Rope
+ private init from_root(r: RopeNode)
do
- var new_rope = new BufferRope
+ root = r
+ end
- var self_iter = self.iterator
- while self_iter.is_ok do
- new_rope.append(self_iter.item.value)
- self_iter.next
- end
+ redef fun length do return root.length
- for i in ropes do
- var iter = i.iterator
- while iter.is_ok do
- new_rope.append(iter.item.value)
- iter.next
- end
- end
+ # Iterator on the nodes of the rope, in forward postfix order
+ private fun postfix(from: Int): Postfix do return new Postfix.from(self, from)
- return new_rope
- end
+ # Iterator on the leaves of the rope, forward order
+ private fun leaves(from: Int): LeavesIterator do return new LeavesIterator(self, from)
- # Appends the content of self multiple times in a new Rope object
- fun *(repeats: Int): Rope do
+ # Iterator on the substrings from 0, in forward order
+ redef fun substrings do return new SubstringsIterator(self, 0)
- var new_rope = new BufferRope
+ # Iterator on the substrings, starting at position `from`, in forward order
+ fun substrings_from(from: Int): IndexedIterator[Text] do return new SubstringsIterator(self, from)
- var str = self.to_s
+ # 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)
- for i in [1 .. repeats] do new_rope.append(str)
+ # Iterator on the leaves of the rope, backwards order
+ private fun reverse_leaves(from: Int): ReverseLeavesIterator do return new ReverseLeavesIterator(self,from)
- return new_rope
- end
+ # Iterator on the substrings, in reverse order
+ fun reverse_substrings: IndexedIterator[Text] do return new ReverseSubstringsIterator(self, length-1)
- # Returns an iterator on self
- #
- # Unsafe modifications on a MutableRope
- #
- private fun iterator: Iterator[LeafNode] do return new DFSRopeLeafIterator(self)
+ # 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)
- # Creates a subrope.
- #
- # var rope = (new BufferRope).append("abcd")
- #
- # assert rope.subrope(1, 2) == "bc"
- # assert rope.subrope(-1, ) == "a"
- # assert rope.subrope(1, 0) == ""
- # assert rope.subrope(2, 5) == "cd"
- #
- # A `index_from` index < 0 will be replaced by 0.
- # Unless a `count` value is > 0 at the same time.
- # In this case, `index_from += count` and `count -= index_from`.
- #
- fun subrope(index_from: Int, count: Int): Rope
+ redef fun output
do
- assert count >= 0
-
- if index_from < 0 then
- count += index_from
- if count < 0 then count = 0
- index_from = 0
+ for i in substrings do
+ i.output
end
+ end
- if count - index_from >= self.length then count = length - index_from
+ redef fun to_cstring
+ do
+ if str_representation != null then return str_representation.as(not null)
- var buffer = new BufferRope
+ var native_final_str = calloc_string(length + 1)
- var iter = new DFSRopeLeafIterator.with_index(self, index_from)
+ native_final_str[length] = '\0'
- var curr_subrope_index = index_from - iter.pos
+ if self.length == 0 then
+ str_representation = native_final_str
+ return native_final_str
+ end
- while iter.is_ok do
- if count == 0 then break
- if curr_subrope_index > 0 then
- if count >= iter.item.value.length then
- buffer.append(iter.item.value.substring(curr_subrope_index, count))
- count -= iter.item.value.length - curr_subrope_index
- curr_subrope_index = 0
- else
- buffer.append(iter.item.value.substring(curr_subrope_index, count))
- break
- end
- else
- if count >= iter.item.value.length then
- buffer.append(iter.item.value)
- count -= iter.item.value.length
- else
- buffer.append(iter.item.value.substring(0, count))
- break
- end
- end
+ var offset = 0
- iter.next
+ 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
- return buffer
- end
+ str_representation = native_final_str
- # Returns an upper (capitalized) version of self
- fun to_upper: Rope
- do
- var new_rope = new BufferRope
- var iter = new DFSRopeLeafIterator(self)
- while iter.is_ok do
- new_rope.append(iter.item.value.to_upper)
- iter.next
- end
- return new_rope
+ return native_final_str
end
- # Returns a lower (minuscule) version of self
- fun to_lower: Rope
+ # Path to the Leaf for `position`
+ private fun node_at(position: Int): Path
do
- var new_rope = new BufferRope
- var iter = new DFSRopeLeafIterator(self)
- while iter.is_ok do
- new_rope.append(iter.item.value.to_lower)
- iter.next
- end
- return new_rope
+ assert position >= 0 and position < length
+ return get_node_from(root.as(not null), 0, position, new List[PathElement])
end
- ############################################################################
- # Comparable Refined Methods #
- ############################################################################
-
- # Compares the current Rope to another object (either another rope or a String)
- redef fun == (other)
+ # 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
- if other == null or not (other isa Rope or other isa FlatText) then return false
- var self_iter = new RopeCharIterator(self)
- if other isa Rope then
- if self.length != other.length then return false
- var other_iterator = new RopeCharIterator(other)
- while self_iter.is_ok do
- if self_iter.item != other_iterator.item then return false
- self_iter.next
- other_iterator.next
- end
- else if other isa FlatText then
- var pos = 0
- if self.length != other.length then return false
- while self_iter.is_ok do
- if self_iter.item != other[pos] then return false
- pos += 1
- self_iter.next
+ 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
- return true
end
- # Checks if self is lesser than other
- #
- # Comparison done in lexicographical order
- # i.e. 'aa' < 'b'
- #
- redef fun <(other)
+ redef fun ==(o)
do
- var other_iter = other.chars.iterator
- for i in self.chars do
- if not other_iter.is_ok then return false
- if i < other_iter.item then return true
- if i > other_iter.item then return false
- other_iter.next
+ 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
- if other_iter.is_ok then return true
- return false
+ return true
end
-
end
-# Rope that can be modified
-#
-# /!\ Non Thread-safe /!\
-#
-class BufferRope
+# Rope that cannot be modified
+class RopeString
super Rope
+ super String
- var is_dirty: Bool = false
+ redef fun to_s do return self
- init
- do
- super
- end
+ redef fun empty do return once new RopeString.from("")
- redef init with_string(str)
- do
- super
- end
-
- ############################################################################
- # Tree Balancing Methods #
- ############################################################################
+ redef var chars: SequenceRead[Char] = new RopeStringChars(self)
- # Performs a right rotation on a node of the Rope
- #
- # Root Pivot
- # / \ / \
- # Pivot Leaf3 => Leaf1 Root
- # / \ / \
- # Leaf1 Leaf2 Leaf2 Leaf3
- private fun rotate_right(root: ConcatNode)
+ redef fun reversed
do
- assert root.left_child != null
- var pivot = root.left_child.as(ConcatNode)
- var root_new_left = pivot.right_child
- var root_parent = root.parent
-
- root.left_child = root_new_left
- pivot.right_child = root
- if root_parent == null then
- self.parent_node = pivot
- pivot.parent = null
- return
+ var ret = empty.as(RopeString)
+ for i in substrings do
+ ret = ret.prepend(i.reversed.to_s).as(RopeString)
end
-
- if root_parent.left_child == root then
- root_parent.left_child = pivot
- else
- root_parent.right_child = pivot
- end
-
- root.update_data
- pivot.update_data
- root_parent.update_data
+ return ret
end
- # Performs a left rotation on a node of the Rope
- #
- # Root Pivot
- # / \ / \
- # Leaf1 Pivot => Root Leaf3
- # / \ / \
- # Leaf2 Leaf3 Leaf1 Leaf2
- private fun rotate_left(root: ConcatNode)
+ redef fun to_upper
do
- assert root.right_child != null
- var pivot = root.right_child.as(ConcatNode)
- var root_new_right = pivot.left_child
- var root_parent = root.parent
-
- root.right_child = root_new_right
- pivot.left_child = root
- if root_parent == null then
- self.parent_node = pivot
- pivot.parent = null
- return
+ var ret = empty
+ for i in substrings do
+ ret += i.to_upper
end
-
- if root_parent.left_child == root then
- root_parent.left_child = pivot
- else
- root_parent.right_child = pivot
- end
-
- root.update_data
- pivot.update_data
- root_parent.update_data
+ return ret
end
- # Shortcut method to balance a node and its parents
- # based on the rules of the AVL Tree
- private fun balance_from_node(parent_node: nullable ConcatNode)
+ redef fun to_lower
do
- while parent_node != null do
- parent_node.update_data
- var node_balance = parent_node.balance_factor
- if node_balance < -1 or node_balance > 1 then
- balance_node(parent_node)
- end
- parent_node = parent_node.parent
+ var ret = empty
+ for i in substrings do
+ ret += i.to_lower
end
+ return ret
end
- # Performs rotations to balance a node according to AVL Tree rules
- private fun balance_node(node: ConcatNode)
+ redef fun +(o) do return insert_at(o.to_s, length)
+
+ redef fun *(n)
do
- var balance_factor = node.balance_factor
- if balance_factor < -1 then
- var right_balance = node.right_child.balance_factor
- if right_balance < 0 then
- rotate_left(node)
- else
- rotate_right(node.right_child.as(ConcatNode))
- rotate_left(node)
- end
- else
- var left_balance = node.left_child.balance_factor
- if left_balance > 0 then
- rotate_right(node)
- else
- rotate_left(node.left_child.as(ConcatNode))
- rotate_right(node)
- end
+ var ret = new RopeString.from("")
+ for i in [0..n[ do
+ ret = (ret + self).as(RopeString)
end
+ return ret
end
- ############################################################################
- # BufferRope exclusive Methods #
- ############################################################################
-
- # Appends a new Collection[Char] at the end of the current rope
- fun append(str: String): BufferRope
+ # Inserts a String `str` at position `pos`
+ redef fun insert_at(str, pos)
do
- var last_node = parent_node
-
- while last_node isa ConcatNode and last_node.right_child != null do
- last_node = last_node.right_child.as(not null)
- end
-
- if last_node isa ConcatNode then
- last_node.right_child = new LeafNode(str.to_s)
- else if last_node isa LeafNode then
- var last_node_parent = last_node.parent
- var new_concat = new ConcatNode
- last_node_parent.right_child = new_concat
- new_concat.left_child = last_node
- new_concat.right_child = new LeafNode(str.to_s)
- last_node = new_concat
- else
- print "Fatal Error, please report to the developers for more insight."
- abort
- end
+ if str.length == 0 then return self
+ if self.length == 0 then return new RopeString.from(str)
- balance_from_node(last_node)
+ assert pos >= 0 and pos <= length
- is_dirty = true
+ if pos == length then return append(str).as(RopeString)
- return self
- end
+ var path = node_at(pos)
- # Variatic function to append several collections of Chars
- fun append_multi(strs: String...): BufferRope
- do
- for i in strs do
- append(i)
- end
- return self
- end
+ var last_concat = new Concat
- # Adds a new Collection[Char] at the beginning of the rope
- fun prepend(str: String): BufferRope
- do
- var curr_node = parent_node
-
- while curr_node isa ConcatNode and curr_node.left_child != null do
- curr_node = curr_node.left_child.as(not null)
- end
-
- if curr_node isa ConcatNode then
- curr_node.left_child = new LeafNode(str.to_s)
- else if curr_node isa LeafNode then
- var parent = curr_node.parent
- var new_concat = new ConcatNode
- var new_leaf = new LeafNode(str.to_s)
- new_concat.left_child = new_leaf
- new_concat.right_child = curr_node
- parent.left_child = new_concat
- curr_node = new_concat
+ if path.offset == 0 then
+ last_concat.right = path.leaf
+ if str isa FlatString then last_concat.left = new Leaf(str) else last_concat.left = str.as(RopeString).root
+ else if path.offset == path.leaf.length then
+ if str isa FlatString then last_concat.right = new Leaf(str) else last_concat.right = str.as(RopeString).root
+ last_concat.left = path.leaf
else
- print "Fatal Error"
- abort
+ 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 = new Concat
+ cct.right = new Leaf(r_half.as(FlatString))
+ last_concat.left = new Leaf(l_half.as(FlatString))
+ if str isa FlatString then last_concat.right = new Leaf(str) else last_concat.right = str.as(RopeString).root
+ cct.left = last_concat
+ last_concat = cct
+ end
+
+ for i in path.stack.reverse_iterator do
+ var nod = new Concat
+ if i.left then
+ nod.right = i.node.right.as(not null)
+ nod.left = last_concat
+ else
+ nod.left = i.node.left.as(not null)
+ nod.right = last_concat
+ end
+ last_concat = nod
end
- balance_from_node(curr_node)
+ return new RopeString.from_root(last_concat)
+ end
- is_dirty = true
+ # Adds `s` at the beginning of self
+ redef fun prepend(s) do return insert_at(s, 0)
- return self
+ # 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
- # Variatic function to prepend several collections of Chars
- fun prepend_multi(strs: String...): BufferRope
+ # Builds a new path from root to the rightmost node with s appended
+ private fun append_to_path(node: RopeNode, s: String): RopeNode
do
- for i in strs do
- prepend(i)
+ var cct = new Concat
+ if node isa Leaf then
+ cct.left = node
+ if s isa FlatString then cct.right = new Leaf(s) else cct.right = s.as(RopeString).root
+ else if node isa Concat then
+ var right = node.right
+ if node.left != null then cct.left = node.left.as(not null)
+ if right == null then
+ if s isa FlatString then cct.right = new Leaf(s) else cct.right = s.as(RopeString).root
+ else
+ cct.right = append_to_path(right, s)
+ end
end
- return self
+ return cct
end
- # Adds the content of `str` after self, does not create a new rope object
- fun concat(str: Rope): Rope
+ # 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
- var other_iter = new DFSRopeLeafIterator(str)
-
- var modif_list = new List[String]
-
- while other_iter.is_ok do
- modif_list.push(other_iter.item.value)
- other_iter.next
+ if pos < 0 then
+ len += pos
+ pos = 0
end
- while modif_list.length > 0 do
- self.append(modif_list.shift)
- end
+ if pos + len > length then len = length - pos
- if not is_dirty then is_dirty = true
+ if len <= 0 then return new RopeString.from("")
- return self
- end
+ var path = node_at(pos)
- # Returns the content of the current BufferRope object as an ImmutableRope
- fun freeze: ImmutableRope
- do
- var buffer_rope = new BufferRope
- var new_rope = new ImmutableRope
+ var lf = path.leaf
+ var offset = path.offset
+
+ if path.leaf.str.length - offset > len then lf = new Leaf(lf.str.substring(offset,len).as(FlatString)) else lf = new Leaf(lf.str.substring_from(offset).as(FlatString))
- var iter = new DFSRopeLeafIterator(self)
+ var nod: RopeNode = lf
- while iter.is_ok do
- buffer_rope.append(iter.item.value)
- iter.next
+ for i in path.stack.reverse_iterator do
+ if i.right then continue
+ var tmp = new Concat
+ tmp.left = nod
+ var r = i.node.right
+ if r != null then tmp.right = r
+ nod = tmp
end
- new_rope.parent_node = buffer_rope.parent_node
+ var ret = new RopeString
+ ret.root = nod
- if not is_dirty then new_rope.str_representation = self.str_representation
+ path = ret.node_at(len-1)
- return new_rope
- end
+ offset = path.offset
+ nod = new Leaf(path.leaf.str.substring(0, offset+1).as(FlatString))
- # Unsafe method to convert self as an ImmutableRope
- #
- # To be used internally only
- private fun to_immutable: ImmutableRope
- do
- var immutable_self = new ImmutableRope
- immutable_self.parent_node = self.parent_node
- return immutable_self
- end
+ for i in path.stack.reverse_iterator do
+ if i.left then continue
+ var tmp = new Concat
+ tmp.right = nod
+ var l = i.node.left
+ if l != null then tmp.left = l
+ nod = tmp
+ end
- ############################################################################
- # Rope refined Methods #
- ############################################################################
+ ret.root = nod
- redef fun subrope(index_from: Int, count: Int): BufferRope
- do
- return super.as(BufferRope)
+ return ret
end
+end
- redef fun *(repeats: Int): BufferRope
- do
- return super.as(BufferRope)
- end
+redef class FlatString
- redef fun +(other: Rope): BufferRope
- do
- return super.as(BufferRope)
- end
+ redef fun append(s) do return (new RopeString.from(self)) + s
- redef fun multi_concat(ropes: Rope...): BufferRope
- do
- return super.as(BufferRope)
- end
+ redef fun prepend(s) do return (new RopeString.from(self)).prepend(s)
- # Refines to add a cache method, calculates only once for every modification
- # the string representation for self
- redef fun to_s
+ redef fun insert_at(s, pos)
do
- if self.str_representation == null or is_dirty then
- self.str_representation = flatten
- is_dirty = false
- end
- return self.str_representation.as(not null)
+ 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
-# Rope that cannot be modified
-class ImmutableRope
- super Rope
+private class RopeStringChars
+ super SequenceRead[Char]
- init
- do
- super
- end
+ var tgt: Rope
- redef init with_string(str)
+ redef fun [](pos)
do
- super
+ assert pos < tgt.length
+ var path = tgt.node_at(pos)
+ return path.leaf.str.chars[path.offset]
end
- ############################################################################
- # Rope refined Methods #
- ############################################################################
+ redef fun iterator do return iterator_from(0)
- redef fun subrope(index_from: Int, count: Int): ImmutableRope
- do
- return (super.as(BufferRope)).to_immutable
- end
+ redef fun iterator_from(pos) do return new RopeCharIterator(tgt, pos)
- redef fun *(repeats: Int): ImmutableRope
- do
- return (super.as(BufferRope)).to_immutable
- end
+ redef fun reverse_iterator do return reverse_iterator_from(tgt.length-1)
- redef fun +(other: Rope): ImmutableRope
- do
- return (super.as(BufferRope)).to_immutable
- end
+ redef fun reverse_iterator_from(pos) do return new ReverseRopeCharIterator(tgt, pos)
+end
- redef fun multi_concat(ropes: Rope...): ImmutableRope
+# Used to iterate on a Rope
+private class IteratorElement
+
+ init(e: RopeNode)
do
- return (super.as(BufferRope)).to_immutable
+ 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
-############################################
-# Rope view classes #
-############################################
+# Simple Postfix iterator on the nodes of a Rope
+private class Postfix
+ super IndexedIterator[RopeNode]
-class CharRopeView
- super SequenceRead[Char]
+ # Target Rope to iterate on
+ var target: Rope
+
+ # Current position in Rope
+ var pos: Int
- # Targeted Rope for the view
- private var target: Rope
+ # Visited nodes
+ var stack = new List[IteratorElement]
- init(tgt: Rope)
+ 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 [](position)
+ redef fun item
do
- var tuple = target.get_node_for_pos(position)
- return tuple.curr_node.value[tuple.corrected_pos]
+ assert is_ok
+ return stack.last.node
end
- redef fun first do return self[0]
+ redef fun is_ok do return not stack.is_empty
- redef fun index_of(char)
- do
- var intern_iter = new RopeCharIterator(target)
- while intern_iter.is_ok do
- if intern_iter.item == char then return intern_iter.index
- intern_iter.next
- end
- return -1
- end
+ redef fun index do return pos
- redef fun iterator do
- return new RopeCharIterator(target)
+ 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
- redef fun last do return self[self.length-1]
+# Iterates on the leaves (substrings) of the Rope
+class LeavesIterator
+ super IndexedIterator[Leaf]
- redef fun length do return target.length
+ private var nodes: Postfix
- redef fun count(item)
+ init(tgt: Rope, pos: Int)
do
- var count = 0
- var iter = self.iterator
-
- for i in self do
- if i == item then count += 1
- end
-
- return count
+ nodes = tgt.postfix(pos)
end
- redef fun has_only(item)
- do
- for i in self do
- if i != item then return false
- end
- return true
- end
-
- redef fun is_empty do return length == 0
+ redef fun is_ok do return nodes.is_ok
- redef fun to_a do
- return to_s.to_a
+ redef fun item
+ do
+ assert is_ok
+ return nodes.item.as(Leaf)
end
- redef fun to_s do
- return target.to_s
- end
+ redef fun index do return nodes.index
- redef fun ==(other)
+ redef fun next
do
- if not other isa SequenceRead[Char] then return false
-
- if self.length != other then return false
-
- var iter = other.iterator
-
- for i in self do
- if i != iter.item then return false
- iter.next
+ while nodes.is_ok do
+ nodes.next
+ if nodes.is_ok and nodes.item isa Leaf then break
end
-
- return true
end
-
end
-###########################################
-# Iterator classes #
-###########################################
-
-# A tuple representing the state of a node for a tree parsing algorithm
-private class TupleVisitNode
+# Uses the leaves and calculates a new substring on each iteration
+class SubstringsIterator
+ super IndexedIterator[Text]
- init(tgt: ConcatNode)
- do
- self.node = tgt
- end
-
- private var node: ConcatNode
+ private var nodes: IndexedIterator[Leaf]
- private var left_visited = false
- private var right_visited = false
-
-end
+ # Current position in Rope
+ var pos: Int
-# Any kind of iterator parsing a Rope for LeafNodes
-private abstract class RopeIterator
- super IndexedIterator[LeafNode]
+ # Current substring, computed from the current Leaf and indexes
+ var substring: Text
- # Rope meant to be visited
- private var _target: Rope
+ 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
- private fun target: Rope do return self._target
+ # 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
- # Position in target
- private var pos = 0
+ redef fun is_ok do return nodes.is_ok
- init(tgt: Rope)
+ redef fun item
do
- self._target = tgt
+ assert is_ok
+ return substring
end
- init with_index(tgt: Rope, index: Int)
+ redef fun index do return pos
+
+ redef fun next
do
- self._target = tgt
+ pos += substring.length
+ nodes.next
+ if nodes.is_ok then make_substring
end
end
-# Iterator returning the content of a rope one char at a time
class RopeCharIterator
super IndexedIterator[Char]
- # The iterator used to visit the rope
- private var sub_str_iter: DFSRopeLeafIterator
+ var substrings: IndexedIterator[Text]
- # The current position in the rope
- private var abs_pos = 0
+ var pos: Int
- # The position in the current substring
- private var sub_pos: Int = 0
+ var max: Int
- # The substring contained in the current node visited by `sub_str_iter`
- private var curr_substring: nullable String
+ var substr_iter: IndexedIterator[Char]
- init(tgt: Rope)
+ init(tgt: Rope, from: Int)
do
- sub_str_iter = new DFSRopeLeafIterator(tgt)
- if sub_str_iter.is_ok then curr_substring = sub_str_iter.item.value
+ 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 curr_substring[sub_pos]
+ redef fun item do return substr_iter.item
- redef fun is_ok
- do
- if sub_str_iter.is_ok then return true
- if not sub_str_iter.is_ok and curr_substring != null and sub_pos < curr_substring.length then return true
- return false
- end
+ redef fun is_ok do return pos <= max
+
+ redef fun index do return pos
redef fun next
do
- assert is_ok
- if sub_pos < curr_substring.length - 1 then
- sub_pos += 1
- else
- sub_str_iter.next
- if sub_str_iter.is_ok then
- curr_substring = sub_str_iter.item.value
- sub_pos = 0
- else
- sub_pos = curr_substring.length
+ 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
- abs_pos += 1
end
-
- redef fun index do return abs_pos
-
end
-# Special kind of iterator
-#
-# Performs a Depth-First Search on RopeLeaf items
-#
-private class DFSRopeLeafIterator
- super RopeIterator
+private class ReversePostfix
+ super IndexedIterator[RopeNode]
- # Stack of the visited nodes in the rope
- private var visit_stack = new List[TupleVisitNode]
+ var target: Rope
- # The leaf node being visited by the iterator
- private var curr_leaf: nullable LeafNode
+ var pos: Int
- init(tgt: Rope)
- do
- super
+ var min = 0
- var first_node = target.parent_node
+ var stack = new List[IteratorElement]
- if first_node isa ConcatNode then
- visit_stack.push(new TupleVisitNode(first_node))
- else if first_node isa LeafNode then
- curr_leaf = first_node
- return
+ 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
-
- next_body
+ stack.push(new IteratorElement(path.leaf))
+ stack.last.done = true
end
- # Creates a new iterator on `tgt` starting at `index`
- redef init with_index(tgt: Rope, index: Int)
- do
- super
-
- var returned_tuple = target.get_node_for_pos(index)
- curr_leaf = returned_tuple.curr_node
- visit_stack = returned_tuple.visit_stack
- pos = index - returned_tuple.corrected_pos
+ redef fun item do
+ assert is_ok
+ return stack.last.node
end
- redef fun is_ok do return curr_leaf != null
+ redef fun is_ok do return not stack.is_empty
+
+ redef fun index do return pos
redef fun next
do
- assert is_ok
- pos += curr_leaf.value.length
- next_body
+ 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 fun next_body
- do
- var next_node: nullable RopeNode
- while not visit_stack.is_empty do
- var curr_concat_tuple = visit_stack.last
- if not curr_concat_tuple.left_visited then
-
- curr_concat_tuple.left_visited = true
-
- next_node = curr_concat_tuple.node.left_child
-
- if next_node == null then continue
-
- if next_node isa ConcatNode then
- visit_stack.push(new TupleVisitNode(next_node))
- else if next_node isa LeafNode then
- curr_leaf = next_node
- return
- end
-
- else if not curr_concat_tuple.right_visited then
+private class ReverseLeavesIterator
+ super IndexedIterator[Leaf]
- curr_concat_tuple.right_visited = true
+ var nodes: ReversePostfix
- next_node = curr_concat_tuple.node.right_child
+ init(tgt: Rope, from: Int)
+ do
+ nodes = tgt.reverse_postfix(from)
+ end
- if next_node == null then continue
+ redef fun is_ok do return nodes.is_ok
- if next_node isa ConcatNode then
- visit_stack.push(new TupleVisitNode(next_node))
- else if next_node isa LeafNode then
- curr_leaf = next_node
- return
- end
+ redef fun item do
+ assert is_ok
+ return nodes.item.as(Leaf)
+ end
- else
- visit_stack.pop
- 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
- self.curr_leaf = null
end
- redef fun item
- do
- assert is_ok
- return curr_leaf.as(not null)
- end
+ redef fun index do return nodes.index
end
-###########################################
-# Node classes #
-###########################################
-
-# A node for a Rope
-private abstract class RopeNode
-
- private var _length = 0
-
- private var parent: nullable ConcatNode = null
-
- private var height = 0
-
- # The balance factor of a node, if it is a Leaf, it equals its length
- # Else, it will be equal to the difference between the height on the left and on the right
- private fun balance_factor: Int do return height end
+private class ReverseSubstringsIterator
+ super IndexedIterator[Text]
- fun length: Int do return _length
+ var leaves: ReverseLeavesIterator
- private fun length=(len: Int)
- do
- _length = len
- end
-end
-
-# Node that represents a concatenation between two nodes (of any RopeNode type)
-private class ConcatNode
- super RopeNode
+ var pos: Int
- private var _left_child: nullable RopeNode = null
- private var _right_child: nullable RopeNode = null
+ var str: Text
- private fun left_child: nullable RopeNode
+ init(tgt: Rope, from: Int)
do
- if _left_child != null then
- return _left_child
- else
- return null
- end
+ leaves = tgt.reverse_leaves(from)
+ pos = from
+ if not leaves.is_ok then return
+ str = leaves.item.str
+ make_substring
end
- private fun right_child: nullable RopeNode
+ fun make_substring
do
- if _right_child != null then
- return _right_child
- else
- return null
- end
+ if pos >= (leaves.index + str.length - 1) then return
+ str = str.substring(0, (pos - leaves.index + 1))
end
- private fun left_child=(new_node: nullable RopeNode)
- do
- self._left_child = new_node
- new_node.parent = self
- update_data
- end
+ redef fun is_ok do return leaves.is_ok
- private fun right_child=(new_node: nullable RopeNode)
- do
- self._right_child = new_node
- new_node.parent = self
- update_data
+ redef fun item do
+ assert is_ok
+ return str
end
- # Updates the internal data of the current node
- #
- # Concretely, updates the length and the height of the node
- private fun update_data
- do
- self.length = 0
- self.height = 1
- if left_child != null then
- self.length += left_child.length
- if left_child.height + 1 > self.height then self.height = left_child.height + 1
- end
- if right_child != null then
- self.length += right_child.length
- if right_child.height + 1 > self.height then self.height = right_child.height + 1
- end
- end
+ redef fun index do return pos
- # Computes and returns the balance factor (used for AVL trees)
- #
- # Formula : left.height - right.height
- redef private fun balance_factor
- do
- var left_height = 0
- var right_height = 0
- if left_child != null then left_height = left_child.height
- if right_child != null then right_height = right_child.height
- return left_height - right_height
+ redef fun next do
+ pos -= str.length
+ leaves.next
+ if not leaves.is_ok then return
+ str = leaves.item.str
+ make_substring
end
end
-# A leaf node contains a substring of some sort
-private class LeafNode
- super RopeNode
+private class ReverseRopeCharIterator
+ super IndexedIterator[Char]
- # Encapsulated string in the leaf node
- private var _value: String
+ var substrs: IndexedIterator[Text]
- init(val: String)
- do
- self._value = val.to_s
- self.length = val.length
- end
+ var pos: Int
- private fun value: String do return self._value
+ var subiter: IndexedIterator[Char]
- private fun value= (val: String)
+ init(tgt: Rope, from: Int)
do
- _value = val
+ 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
-end
-#####################################################
-# Foreign classes refinement #
-#####################################################
+ redef fun is_ok do return pos >= 0
-redef class String
- redef fun ==(other)
- do
- if other isa Rope then
- return other == self
- else
- return super
- end
+ redef fun item do
+ assert is_ok
+ return subiter.item
end
-end
-redef class Buffer
- redef fun ==(other)
- do
- if other isa Rope then
- return other == self
- else
- return super
+ 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 / commitdiff