Remove dependency on scala-xml.

Mimic https://github.com/scala/scala/commit/4e9b33ab24bb3bf922c37a05a79af364b7b32b84

1 files changed, 169 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/parsing/Utility.scala b/src/dotty/tools/dotc/parsing/Utility.scala
new file mode 100644
index 000000000..44ed268e1
--- /dev/null
+++ b/src/dotty/tools/dotc/parsing/Utility.scala
@@ -0,0 +1,169 @@
+package dotty.tools.dotc.parsing
+
+import scala.collection.mutable
+
+
+/**
+ * The `Utility` object provides utility functions for processing instances
+ * of bound and not bound XML classes, as well as escaping text nodes.
+ *
+ * @author Burak Emir
+ */
+object Utility {
+  import scala.reflect.internal.Chars.SU
+
+  private val unescMap = Map(
+    "lt"    -> '<',
+    "gt"    -> '>',
+    "amp"   -> '&',
+    "quot"  -> '"',
+    "apos"  -> '\''
+  )
+
+  /**
+   * Appends unescaped string to `s`, `amp` becomes `&amp;`,
+   * `lt` becomes `&lt;` etc..
+   *
+   * @return    `'''null'''` if `ref` was not a predefined entity.
+   */
+  private final def unescape(ref: String, s: StringBuilder): StringBuilder =
+    ((unescMap get ref) map (s append _)).orNull
+
+  def parseAttributeValue[T](value: String, text: String => T, entityRef: String => T): List[T] = {
+    val sb  = new StringBuilder
+    var rfb: StringBuilder = null
+    val nb = new mutable.ListBuffer[T]()
+
+    val it = value.iterator
+    while (it.hasNext) {
+      var c = it.next()
+      // entity! flush buffer into text node
+      if (c == '&') {
+        c = it.next()
+        if (c == '#') {
+          c = it.next()
+          val theChar = parseCharRef ({ ()=> c },{ () => c = it.next() },{s => throw new RuntimeException(s)}, {s => throw new RuntimeException(s)})
+          sb.append(theChar)
+        }
+        else {
+          if (rfb eq null) rfb = new StringBuilder()
+          rfb append c
+          c = it.next()
+          while (c != ';') {
+            rfb.append(c)
+            c = it.next()
+          }
+          val ref = rfb.toString()
+          rfb.clear()
+          unescape(ref,sb) match {
+            case null =>
+              if (!sb.isEmpty) {  // flush buffer
+                nb += text(sb.toString())
+                sb.clear()
+              }
+              nb += entityRef(ref) // add entityref
+            case _ =>
+          }
+        }
+      }
+      else sb append c
+    }
+
+    if(!sb.isEmpty) // flush buffer
+      nb += text(sb.toString())
+
+    nb.toList
+  }
+
+  /**
+   * {{{
+   *   CharRef ::= "&amp;#" '0'..'9' {'0'..'9'} ";"
+   *             | "&amp;#x" '0'..'9'|'A'..'F'|'a'..'f' { hexdigit } ";"
+   * }}}
+   * See [66]
+   */
+  def parseCharRef(ch: () => Char, nextch: () => Unit, reportSyntaxError: String => Unit, reportTruncatedError: String => Unit): String = {
+    val hex  = (ch() == 'x') && { nextch(); true }
+    val base = if (hex) 16 else 10
+    var i = 0
+    while (ch() != ';') {
+      ch() match {
+        case '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' =>
+          i = i * base + ch().asDigit
+        case 'a' | 'b' | 'c' | 'd' | 'e' | 'f'
+           | 'A' | 'B' | 'C' | 'D' | 'E' | 'F' =>
+          if (! hex)
+            reportSyntaxError("hex char not allowed in decimal char ref\n" +
+                              "Did you mean to write &#x ?")
+          else
+            i = i * base + ch().asDigit
+        case SU =>
+          reportTruncatedError("")
+        case _ =>
+          reportSyntaxError("character '" + ch() + "' not allowed in char ref\n")
+      }
+      nextch()
+    }
+    new String(Array(i), 0, 1)
+  }
+
+  /** {{{
+   *  (#x20 | #x9 | #xD | #xA)
+   *  }}} */
+  final def isSpace(ch: Char): Boolean = ch match {
+    case '\u0009' | '\u000A' | '\u000D' | '\u0020' => true
+    case _                                         => false
+  }
+  /** {{{
+   *  (#x20 | #x9 | #xD | #xA)+
+   *  }}} */
+  final def isSpace(cs: Seq[Char]): Boolean = cs.nonEmpty && (cs forall isSpace)
+
+  /** {{{
+   *  NameChar ::= Letter | Digit | '.' | '-' | '_' | ':'
+   *             | CombiningChar | Extender
+   *  }}}
+   *  See [4] and Appendix B of XML 1.0 specification.
+  */
+  def isNameChar(ch: Char) = {
+    import java.lang.Character._
+    // The constants represent groups Mc, Me, Mn, Lm, and Nd.
+
+    isNameStart(ch) || (getType(ch).toByte match {
+      case COMBINING_SPACING_MARK |
+              ENCLOSING_MARK | NON_SPACING_MARK |
+              MODIFIER_LETTER | DECIMAL_DIGIT_NUMBER => true
+      case _                                         => ".-:" contains ch
+    })
+  }
+
+  /** {{{
+   *  NameStart ::= ( Letter | '_' )
+   *  }}}
+   *  where Letter means in one of the Unicode general
+   *  categories `{ Ll, Lu, Lo, Lt, Nl }`.
+   *
+   *  We do not allow a name to start with `:`.
+   *  See [3] and Appendix B of XML 1.0 specification
+   */
+  def isNameStart(ch: Char) = {
+    import java.lang.Character._
+
+    getType(ch).toByte match {
+      case LOWERCASE_LETTER |
+              UPPERCASE_LETTER | OTHER_LETTER |
+              TITLECASE_LETTER | LETTER_NUMBER => true
+      case _                                   => ch == '_'
+    }
+  }
+
+  /** {{{
+   *  Name ::= ( Letter | '_' ) (NameChar)*
+   *  }}}
+   *  See [5] of XML 1.0 specification.
+   */
+  def isName(s: String) =
+    s.nonEmpty && isNameStart(s.head) && (s.tail forall isNameChar)
+
+}
+