1 files changed, 264 insertions, 0 deletions
diff --git a/compiler/src/dotty/tools/dotc/parsing/SymbolicXMLBuilder.scala b/compiler/src/dotty/tools/dotc/parsing/SymbolicXMLBuilder.scala
new file mode 100644
index 000000000..20b655a19
--- /dev/null
+++ b/compiler/src/dotty/tools/dotc/parsing/SymbolicXMLBuilder.scala
@@ -0,0 +1,264 @@
+package dotty.tools
+package dotc
+package parsing
+
+import scala.collection.mutable
+import scala.xml.{ EntityRef, Text }
+import core._
+import Flags.Mutable
+import Names._, StdNames._, ast.Trees._, ast.{tpd, untpd}
+import Symbols._, Contexts._
+import util.Positions._
+import Parsers.Parser
+import scala.reflect.internal.util.StringOps.splitWhere
+import scala.language.implicitConversions
+
+/** This class builds instance of `Tree` that represent XML.
+ *
+ *  Note from martin: This needs to have its position info reworked. I don't
+ *  understand exactly what's done here. To make validation pass, I set many
+ *  positions to be transparent. Not sure this is a good idea for navigating
+ *  XML trees in the IDE but it's the best I can do right now. If someone
+ *  who understands this part better wants to give it a shot, please do!
+ *
+ *  @author  Burak Emir
+ *  @version 1.0
+ */
+class SymbolicXMLBuilder(parser: Parser, preserveWS: Boolean)(implicit ctx: Context) {
+
+  import Constants.Constant
+  import untpd._
+
+  import parser.atPos
+
+  private[parsing] var isPattern: Boolean = _
+
+  private object xmltypes extends ScalaTypeNames {
+    val _Comment: TypeName             = "Comment"
+    val _Elem: TypeName                = "Elem"
+    val _EntityRef: TypeName           = "EntityRef"
+    val _Group: TypeName               = "Group"
+    val _MetaData: TypeName            = "MetaData"
+    val _NamespaceBinding: TypeName    = "NamespaceBinding"
+    val _NodeBuffer: TypeName          = "NodeBuffer"
+    val _PrefixedAttribute: TypeName   = "PrefixedAttribute"
+    val _ProcInstr: TypeName           = "ProcInstr"
+    val _Text: TypeName                = "Text"
+    val _Unparsed: TypeName            = "Unparsed"
+    val _UnprefixedAttribute: TypeName = "UnprefixedAttribute"
+  }
+
+  private object xmlterms extends ScalaTermNames {
+    val _Null: TermName     = "Null"
+    val __Elem: TermName    = "Elem"
+    val __Text: TermName    = "Text"
+    val _buf: TermName      = "$buf"
+    val _md: TermName       = "$md"
+    val _plus: TermName     = "$amp$plus"
+    val _scope: TermName    = "$scope"
+    val _tmpscope: TermName = "$tmpscope"
+    val _xml: TermName      = "xml"
+  }
+
+  import xmltypes.{_Comment, _Elem, _EntityRef, _Group, _MetaData, _NamespaceBinding, _NodeBuffer,
+    _PrefixedAttribute, _ProcInstr, _Text, _Unparsed, _UnprefixedAttribute}
+
+  import xmlterms.{_Null, __Elem, __Text, _buf, _md, _plus, _scope, _tmpscope, _xml}
+
+  // convenience methods
+  private def LL[A](x: A*): List[List[A]] = List(List(x:_*))
+  private def const(x: Any) = Literal(Constant(x))
+  private def wild                          = Ident(nme.WILDCARD)
+  private def wildStar                      = Ident(tpnme.WILDCARD_STAR)
+  private def _scala(name: Name)            = scalaDot(name)
+  private def _scala_xml(name: Name)        = Select(_scala(_xml), name)
+
+  private def _scala_xml_Comment            = _scala_xml(_Comment)
+  private def _scala_xml_Elem               = _scala_xml(_Elem)
+  private def _scala_xml_EntityRef          = _scala_xml(_EntityRef)
+  private def _scala_xml_Group              = _scala_xml(_Group)
+  private def _scala_xml_MetaData           = _scala_xml(_MetaData)
+  private def _scala_xml_NamespaceBinding   = _scala_xml(_NamespaceBinding)
+  private def _scala_xml_NodeBuffer         = _scala_xml(_NodeBuffer)
+  private def _scala_xml_Null               = _scala_xml(_Null)
+  private def _scala_xml_PrefixedAttribute  = _scala_xml(_PrefixedAttribute)
+  private def _scala_xml_ProcInstr          = _scala_xml(_ProcInstr)
+  private def _scala_xml_Text               = _scala_xml(_Text)
+  private def _scala_xml_Unparsed           = _scala_xml(_Unparsed)
+  private def _scala_xml_UnprefixedAttribute= _scala_xml(_UnprefixedAttribute)
+  private def _scala_xml__Elem              = _scala_xml(__Elem)
+  private def _scala_xml__Text              = _scala_xml(__Text)
+
+  /** Wildly wrong documentation deleted in favor of "self-documenting code." */
+  protected def mkXML(
+    pos: Position,
+    isPattern: Boolean,
+    pre: Tree,
+    label: Tree,
+    attrs: Tree,
+    scope: Tree,
+    empty: Boolean,
+    children: Seq[Tree]): Tree =
+  {
+    def starArgs =
+      if (children.isEmpty) Nil
+      else List(Typed(makeXMLseq(pos, children), wildStar))
+
+    def pat    = Apply(_scala_xml__Elem, List(pre, label, wild, wild) ::: convertToTextPat(children))
+    def nonpat = New(_scala_xml_Elem, List(List(pre, label, attrs, scope, if (empty) Literal(Constant(true)) else Literal(Constant(false))) ::: starArgs))
+
+    atPos(pos) { if (isPattern) pat else nonpat }
+  }
+
+  final def entityRef(pos: Position, n: String) =
+    atPos(pos)( New(_scala_xml_EntityRef, LL(const(n))) )
+
+  // create scala.xml.Text here <: scala.xml.Node
+  final def text(pos: Position, txt: String): Tree = atPos(pos) {
+    if (isPattern) makeTextPat(const(txt))
+    else makeText1(const(txt))
+  }
+
+  def makeTextPat(txt: Tree)                = Apply(_scala_xml__Text, List(txt))
+  def makeText1(txt: Tree)                  = New(_scala_xml_Text, LL(txt))
+  def comment(pos: Position, text: String)  = atPos(pos)( Comment(const(text)) )
+  def charData(pos: Position, txt: String)  = atPos(pos)( makeText1(const(txt)) )
+
+  def procInstr(pos: Position, target: String, txt: String) =
+    atPos(pos)( ProcInstr(const(target), const(txt)) )
+
+  protected def Comment(txt: Tree)                  = New(_scala_xml_Comment, LL(txt))
+  protected def ProcInstr(target: Tree, txt: Tree)  = New(_scala_xml_ProcInstr, LL(target, txt))
+
+  /** @todo: attributes */
+  def makeXMLpat(pos: Position, n: String, args: Seq[Tree]): Tree = {
+    val (prepat, labpat) = splitPrefix(n) match {
+      case (Some(pre), rest)  => (const(pre), const(rest))
+      case _                  => (wild, const(n))
+    }
+    mkXML(pos, true, prepat, labpat, null, null, false, args)
+  }
+
+  protected def convertToTextPat(t: Tree): Tree = t match {
+    case _: Literal => makeTextPat(t)
+    case _          => t
+  }
+  protected def convertToTextPat(buf: Seq[Tree]): List[Tree] =
+    (buf map convertToTextPat).toList
+
+  def parseAttribute(pos: Position, s: String): Tree = {
+    val ts = scala.xml.Utility.parseAttributeValue(s) map {
+      case Text(s)      => text(pos, s)
+      case EntityRef(s) => entityRef(pos, s)
+    }
+    ts.length match {
+      case 0 => TypedSplice(tpd.ref(defn.NilModule) withPos pos)
+      case 1 => ts.head
+      case _ => makeXMLseq(pos, ts.toList)
+    }
+  }
+
+  def isEmptyText(t: Tree) = t match {
+    case Literal(Constant("")) => true
+    case _ => false
+  }
+
+  /** could optimize if args.length == 0, args.length == 1 AND args(0) is <: Node. */
+  def makeXMLseq(pos: Position, args: Seq[Tree]) = {
+    val buffer = ValDef(_buf, TypeTree(), New(_scala_xml_NodeBuffer, ListOfNil))
+    val applies = args filterNot isEmptyText map (t => Apply(Select(Ident(_buf), _plus), List(t)))
+
+    atPos(pos)( Block(buffer :: applies.toList, Ident(_buf)) )
+  }
+
+  /** Returns (Some(prefix) | None, rest) based on position of ':' */
+  def splitPrefix(name: String): (Option[String], String) = splitWhere(name, _ == ':', true) match {
+    case Some((pre, rest))  => (Some(pre), rest)
+    case _                  => (None, name)
+  }
+
+  /** Various node constructions. */
+  def group(pos: Position, args: Seq[Tree]): Tree =
+    atPos(pos)( New(_scala_xml_Group, LL(makeXMLseq(pos, args))) )
+
+  def unparsed(pos: Position, str: String): Tree =
+    atPos(pos)( New(_scala_xml_Unparsed, LL(const(str))) )
+
+  def element(pos: Position, qname: String, attrMap: mutable.Map[String, Tree], empty: Boolean, args: Seq[Tree]): Tree = {
+    def handleNamespaceBinding(pre: String, z: String): Tree = {
+      def mkAssign(t: Tree): Tree = Assign(
+        Ident(_tmpscope),
+        New(_scala_xml_NamespaceBinding, LL(const(pre), t, Ident(_tmpscope)))
+      )
+
+      val uri1 = attrMap(z) match {
+        case Apply(_, List(uri @ Literal(Constant(_)))) => mkAssign(uri)
+        case Select(_, nme.Nil)                         => mkAssign(const(null))  // allow for xmlns="" -- bug #1626
+        case x                                          => mkAssign(x)
+      }
+      attrMap -= z
+      uri1
+    }
+
+    /** Extract all the namespaces from the attribute map. */
+    val namespaces: List[Tree] =
+      for (z <- attrMap.keys.toList ; if z startsWith "xmlns") yield {
+        val ns = splitPrefix(z) match {
+          case (Some(_), rest)  => rest
+          case _                => null
+        }
+        handleNamespaceBinding(ns, z)
+      }
+
+    val (pre, newlabel) = splitPrefix(qname) match {
+      case (Some(p), x) => (p, x)
+      case (None, x)    => (null, x)
+    }
+
+    def mkAttributeTree(pre: String, key: String, value: Tree) = atPos(pos.toSynthetic) {
+      // XXX this is where we'd like to put Select(value, nme.toString_) for #1787
+      // after we resolve the Some(foo) situation.
+      val baseArgs = List(const(key), value, Ident(_md))
+      val (clazz, attrArgs) =
+        if (pre == null) (_scala_xml_UnprefixedAttribute, baseArgs)
+                    else (_scala_xml_PrefixedAttribute  , const(pre) :: baseArgs)
+
+      Assign(Ident(_md), New(clazz, LL(attrArgs: _*)))
+    }
+
+    def handlePrefixedAttribute(pre: String, key: String, value: Tree)  = mkAttributeTree(pre, key, value)
+    def handleUnprefixedAttribute(key: String, value: Tree)             = mkAttributeTree(null, key, value)
+
+    val attributes: List[Tree] =
+      for ((k, v) <- attrMap.toList.reverse) yield splitPrefix(k) match {
+        case (Some(pre), rest)  => handlePrefixedAttribute(pre, rest, v)
+        case _                  => handleUnprefixedAttribute(k, v)
+      }
+
+    lazy val scopeDef     = ValDef(_scope, _scala_xml_NamespaceBinding, Ident(_tmpscope))
+    lazy val tmpScopeDef  = ValDef(_tmpscope, _scala_xml_NamespaceBinding, Ident(_scope)).withFlags(Mutable)
+    lazy val metadataDef  = ValDef(_md, _scala_xml_MetaData, _scala_xml_Null).withFlags(Mutable)
+    val makeSymbolicAttrs = if (!attributes.isEmpty) Ident(_md) else _scala_xml_Null
+
+    val (attrResult, nsResult) =
+      (attributes.isEmpty, namespaces.isEmpty) match {
+        case (true ,  true)   => (Nil, Nil)
+        case (true , false)   => (scopeDef :: Nil, tmpScopeDef :: namespaces)
+        case (false,  true)   => (metadataDef :: attributes, Nil)
+        case (false, false)   => (scopeDef :: metadataDef :: attributes, tmpScopeDef :: namespaces)
+      }
+
+    val body = mkXML(
+      pos.toSynthetic,
+      false,
+      const(pre),
+      const(newlabel),
+      makeSymbolicAttrs,
+      Ident(_scope),
+      empty,
+      args
+    )
+
+    atPos(pos.toSynthetic)( Block(nsResult, Block(attrResult, body)) )
+  }
+}