1/*  Title:      Pure/PIDE/markup_tree.scala
2    Author:     Fabian Immler, TU Munich
3    Author:     Makarius
4
5Markup trees over nested / non-overlapping text ranges.
6*/
7
8package isabelle
9
10
11import scala.collection.immutable.SortedMap
12import scala.collection.mutable
13import scala.annotation.tailrec
14
15
16object Markup_Tree
17{
18  /* construct trees */
19
20  val empty: Markup_Tree = new Markup_Tree(Branches.empty)
21
22  def merge(trees: List[Markup_Tree], range: Text.Range, elements: Markup.Elements): Markup_Tree =
23    (empty /: trees)(_.merge(_, range, elements))
24
25  def merge_disjoint(trees: List[Markup_Tree]): Markup_Tree =
26    trees match {
27      case Nil => empty
28      case head :: tail =>
29        new Markup_Tree(
30          (head.branches /: tail) {
31            case (branches, tree) =>
32              (branches /: tree.branches) {
33                case (bs, (r, entry)) =>
34                  require(!bs.isDefinedAt(r))
35                  bs + (r -> entry)
36              }
37          })
38    }
39
40
41  /* tree building blocks */
42
43  object Entry
44  {
45    def apply(markup: Text.Markup, subtree: Markup_Tree): Entry =
46      Entry(markup.range, List(markup.info), subtree)
47  }
48
49  sealed case class Entry(
50    range: Text.Range,
51    rev_markup: List[XML.Elem],
52    subtree: Markup_Tree)
53  {
54    def markup: List[XML.Elem] = rev_markup.reverse
55
56    def filter_markup(elements: Markup.Elements): List[XML.Elem] =
57    {
58      var result: List[XML.Elem] = Nil
59      for (elem <- rev_markup if elements(elem.name))
60        result ::= elem
61      result.toList
62    }
63
64    def + (markup: Text.Markup): Entry = copy(rev_markup = markup.info :: rev_markup)
65    def \ (markup: Text.Markup): Entry = copy(subtree = subtree + markup)
66  }
67
68  object Branches
69  {
70    type T = SortedMap[Text.Range, Entry]
71    val empty: T = SortedMap.empty(Text.Range.Ordering)
72  }
73
74
75  /* XML representation */
76
77  @tailrec private def strip_elems(
78      elems: List[XML.Elem], body: XML.Body): (List[XML.Elem], XML.Body) =
79    body match {
80      case List(XML.Wrapped_Elem(markup1, body1, body2)) =>
81        strip_elems(XML.Elem(markup1, body1) :: elems, body2)
82      case List(XML.Elem(markup1, body1)) =>
83        strip_elems(XML.Elem(markup1, Nil) :: elems, body1)
84      case _ => (elems, body)
85    }
86
87  private def make_trees(acc: (Int, List[Markup_Tree]), tree: XML.Tree): (Int, List[Markup_Tree]) =
88    {
89      val (offset, markup_trees) = acc
90
91      strip_elems(Nil, List(tree)) match {
92        case (Nil, body) =>
93          (offset + XML.text_length(body), markup_trees)
94
95        case (elems, body) =>
96          val (end_offset, subtrees) = ((offset, Nil: List[Markup_Tree]) /: body)(make_trees)
97          if (offset == end_offset) acc
98          else {
99            val range = Text.Range(offset, end_offset)
100            val entry = Entry(range, elems, merge_disjoint(subtrees))
101            (end_offset, new Markup_Tree(Branches.empty, entry) :: markup_trees)
102          }
103      }
104    }
105
106  def from_XML(body: XML.Body): Markup_Tree =
107    merge_disjoint(((0, Nil: List[Markup_Tree]) /: body)(make_trees)._2)
108}
109
110
111final class Markup_Tree private(val branches: Markup_Tree.Branches.T)
112{
113  import Markup_Tree._
114
115  private def this(branches: Markup_Tree.Branches.T, entry: Markup_Tree.Entry) =
116    this(branches + (entry.range -> entry))
117
118  private def overlapping(range: Text.Range): Branches.T =
119    if (branches.isEmpty ||
120        (range.contains(branches.firstKey.start) && branches.lastKey.stop <= range.stop))
121      branches
122    else {
123      val start = Text.Range(range.start)
124      val stop = Text.Range(range.stop)
125      val bs = branches.range(start, stop)
126      branches.get(stop) match {
127        case Some(end) if range overlaps end.range => bs + (end.range -> end)
128        case _ => bs
129      }
130    }
131
132  def restrict(range: Text.Range): Markup_Tree =
133    new Markup_Tree(overlapping(range))
134
135  def is_empty: Boolean = branches.isEmpty
136
137  def + (new_markup: Text.Markup): Markup_Tree =
138  {
139    val new_range = new_markup.range
140
141    branches.get(new_range) match {
142      case None => new Markup_Tree(branches, Entry(new_markup, empty))
143      case Some(entry) =>
144        if (entry.range == new_range)
145          new Markup_Tree(branches, entry + new_markup)
146        else if (entry.range.contains(new_range))
147          new Markup_Tree(branches, entry \ new_markup)
148        else if (new_range.contains(branches.head._1) && new_range.contains(branches.last._1))
149          new Markup_Tree(Branches.empty, Entry(new_markup, this))
150        else {
151          val body = overlapping(new_range)
152          if (body.forall(e => new_range.contains(e._1)))
153            new Markup_Tree(branches -- body.keys, Entry(new_markup, new Markup_Tree(body)))
154          else {
155            Output.warning("Ignored overlapping markup information: " + new_markup + "\n" +
156              body.filter(e => !new_range.contains(e._1)).values.mkString("\n"))
157            this
158          }
159        }
160    }
161  }
162
163  def merge(other: Markup_Tree, root_range: Text.Range, elements: Markup.Elements): Markup_Tree =
164  {
165    def merge_trees(tree1: Markup_Tree, tree2: Markup_Tree): Markup_Tree =
166      (tree1 /: tree2.branches)(
167        { case (tree, (range, entry)) =>
168            if (!range.overlaps(root_range)) tree
169            else
170              (merge_trees(tree, entry.subtree) /: entry.filter_markup(elements))(
171                { case (t, elem) => t + Text.Info(range, elem) })
172        })
173
174    if (this eq other) this
175    else {
176      val tree1 = this.restrict(root_range)
177      val tree2 = other.restrict(root_range)
178      if (tree1.is_empty) tree2
179      else merge_trees(tree1, tree2)
180    }
181  }
182
183  def cumulate[A](root_range: Text.Range, root_info: A, elements: Markup.Elements,
184    result: (A, Text.Markup) => Option[A]): List[Text.Info[A]] =
185  {
186    def results(x: A, entry: Entry): Option[A] =
187    {
188      var y = x
189      var changed = false
190      for {
191        elem <- entry.filter_markup(elements)
192        y1 <- result(y, Text.Info(entry.range, elem))
193      } { y = y1; changed = true }
194      if (changed) Some(y) else None
195    }
196
197    def traverse(
198      last: Text.Offset,
199      stack: List[(Text.Info[A], List[(Text.Range, Entry)])]): List[Text.Info[A]] =
200    {
201      stack match {
202        case (parent, (range, entry) :: more) :: rest =>
203          val subrange = range.restrict(root_range)
204          val subtree = entry.subtree.overlapping(subrange).toList
205          val start = subrange.start
206
207          results(parent.info, entry) match {
208            case Some(res) =>
209              val next = Text.Info(subrange, res)
210              val nexts = traverse(start, (next, subtree) :: (parent, more) :: rest)
211              if (last < start) parent.restrict(Text.Range(last, start)) :: nexts
212              else nexts
213            case None => traverse(last, (parent, subtree ::: more) :: rest)
214          }
215
216        case (parent, Nil) :: rest =>
217          val stop = parent.range.stop
218          val nexts = traverse(stop, rest)
219          if (last < stop) parent.restrict(Text.Range(last, stop)) :: nexts
220          else nexts
221
222        case Nil =>
223          val stop = root_range.stop
224          if (last < stop) List(Text.Info(Text.Range(last, stop), root_info))
225          else Nil
226      }
227    }
228    traverse(root_range.start,
229      List((Text.Info(root_range, root_info), overlapping(root_range).toList)))
230  }
231
232  def to_XML(root_range: Text.Range, text: CharSequence, elements: Markup.Elements): XML.Body =
233  {
234    def make_text(start: Text.Offset, stop: Text.Offset): XML.Body =
235      if (start == stop) Nil
236      else List(XML.Text(text.subSequence(start, stop).toString))
237
238    def make_elems(rev_markups: List[XML.Elem], body: XML.Body): XML.Body =
239      (body /: rev_markups) {
240        case (b, elem) =>
241          if (!elements(elem.name)) b
242          else if (elem.body.isEmpty) List(XML.Elem(elem.markup, b))
243          else List(XML.Wrapped_Elem(elem.markup, elem.body, b))
244      }
245
246    def make_body(elem_range: Text.Range, elem_markup: List[XML.Elem], entries: Branches.T)
247      : XML.Body =
248    {
249      val body = new mutable.ListBuffer[XML.Tree]
250      var last = elem_range.start
251      for ((range, entry) <- entries) {
252        val subrange = range.restrict(elem_range)
253        body ++= make_text(last, subrange.start)
254        body ++= make_body(subrange, entry.rev_markup, entry.subtree.overlapping(subrange))
255        last = subrange.stop
256      }
257      body ++= make_text(last, elem_range.stop)
258      make_elems(elem_markup, body.toList)
259    }
260   make_body(root_range, Nil, overlapping(root_range))
261  }
262
263  override def toString: String =
264    branches.toList.map(_._2) match {
265      case Nil => "Empty"
266      case list => list.mkString("Tree(", ",", ")")
267    }
268}
269