files for io, used by xml parsing

2 files changed, 205 insertions, 0 deletions

diff --git a/sources/scala/io/Position.scala b/sources/scala/io/Position.scala
new file mode 100644
index 0000000000..4fb57b9dc7
--- /dev/null
+++ b/sources/scala/io/Position.scala
@@ -0,0 +1,84 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2004, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+package scala.io;
+
+/** convenience methods to encode line and column number in one
+ *  single integer. The encode line (column)
+ * numbers range from 0 to LINE_MASK (COLUMN_MASK), where 0 indicates
+ * that the line (column) is the undefined and 1 represents the first
+ * line (column). Line (Column) numbers greater than LINE_MASK
+ * (COLUMN_MASK) are replaced by LINE_MASK (COLUMN_MASK). Furthermore,
+ * if the encoded line number is LINE_MASK, the column number is
+ * always set to 0.
+
+ * The following properties hold:
+ * - the undefined position is 0: encode(0,0) == 0
+ * - encodings are non-negative : encode(line,column) >= 0
+ * - position order is preserved:
+ *   (line1 < line2) || (line1 == line2 && column1 < column2)
+ * implies
+ *   encode(line1,column1) <= encode(line2,column2)
+ *  @author Burak Emir (translated from work by Matthias Zengers and others)
+ */
+object Position {
+
+  /** Number of bits used to encode the line number */
+  final val LINE_BITS   = 20;
+  /** Number of bits used to encode the column number */
+  final val COLUMN_BITS = 31 - LINE_BITS; // no negatives => 31
+
+  /** Mask to decode the line number */
+  final val LINE_MASK   = (1 << LINE_BITS) - 1;
+  /** Mask to decode the column number */
+  final val COLUMN_MASK = (1 << COLUMN_BITS) - 1;
+
+  /** The undefined position */
+  final val NOPOS       = 0;
+
+  /** The first position in a source file */
+  final val FIRSTPOS    = encode(1, 1);
+
+    //########################################################################
+    // Public Functions
+
+  /** Encodes a position into a single integer. */
+  final def encode(line: Int, column: Int): Int = {
+    var line1, column1 = 0;
+    if( line < 0 )
+      error(line+" < 0");
+    if(( line == 0 )&&(column != 0))
+      error(line+","+column+" not allowed");
+    if( column < 0 )
+      error(line+","+column+" not allowed");
+
+    if (line >= LINE_MASK) { line1 = LINE_MASK; column1 = 0; }
+    if (column > COLUMN_MASK) column1 = COLUMN_MASK;
+    (line1 << COLUMN_BITS) | column1;
+  }
+
+  /** Returns the line number of the encoded position. */
+  final def line(pos: Int): Int = {
+    (pos >> COLUMN_BITS) & LINE_MASK;
+  }
+
+  /** Returns the column number of the encoded position. */
+  final def column(pos: Int): Int = {
+    pos & COLUMN_MASK;
+  }
+
+  /** Returns a string representation of the encoded position. */
+  def toString(pos: Int): String = {
+    val sb = new StringBuffer();
+    sb.append(line(pos));
+    sb.append(':');
+    sb.append(column(pos));
+    sb.toString();
+  }
+}
diff --git a/sources/scala/io/Source.scala b/sources/scala/io/Source.scala
new file mode 100644
index 0000000000..8c22e2f3bf
--- /dev/null
+++ b/sources/scala/io/Source.scala
@@ -0,0 +1,121 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2004, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+package scala.io;
+
+/** convenience methods to create an iterable representation of a source file
+ *  @author Burak Emir
+ */
+object Source {
+
+  /** creates Source from array of bytes, with empty description
+   */
+  def fromBytes(bytes: Array[Byte]): Source =
+    fromString(new String(bytes));
+
+  /** creates Source from array of bytes with given encoding, with empty description
+   */
+  def fromBytes(bytes: Array[Byte], enc: String): Source =
+    fromString(new String(bytes, enc));
+
+  /** creates Source from array of characters, with empty description
+   */
+  def fromChars(chars: Array[Char]): Source = {
+    val it = Iterator.fromArray(chars);
+    new Source {
+      val iter = it;
+    }
+  }
+  /** creates Source from string, with empty description
+   */
+  def fromString(s: String): Source = {
+    val it = Iterator.fromString(s);
+    new Source {
+      val iter = it;
+    }
+  }
+
+  /** creates Source from file with given name, setting its description to
+   *  filename.
+   */
+  def fromFile(name: String): Source =
+    fromFile( new java.io.File( name ));
+
+  /** creates Source from file with given name, using given encoding, setting
+   *  its description to filename.
+   */
+  def fromFile(name: String, enc: String): Source =
+    fromFile( new java.io.File( name ), enc);
+
+  /** creates Source from file, using default character encoding, setting its
+   *  description to filename.
+   */
+  def fromFile(file: java.io.File): Source = {
+    val arr: Array[Byte] = new Array[Byte]( file.length().asInstanceOf[Int] );
+    val is = new java.io.FileInputStream( file );
+    is.read( arr );
+    val s = fromBytes(arr);
+    s.descr = file.getName();
+    s
+  }
+
+  /** creates Source from file, using given character encoding, setting its
+   *  description to filename.
+   */
+  def fromFile(file: java.io.File, enc: String): Source = {
+    val arr: Array[Byte] = new Array[Byte]( file.length().asInstanceOf[Int] );
+    val is = new java.io.FileInputStream( file );
+    is.read( arr );
+    val s = fromBytes(arr, enc);
+    s.descr = file.getName();
+    s
+  }
+}
+
+/** an iterable representation of source files.
+ *  @author Burak Emir
+ */
+abstract class Source extends Iterator[Char] {
+  /** default col increment for tabs '\t', set to 4 */
+  val tabinc = 4;
+
+  val iter: Iterator[Char];
+  /** returns next characters, updates positions and assigns the character
+   *  ch as side effect
+   */
+  def next = {
+    ch = iter.next;
+    pos = Position.encode(cline,ccol);
+    ch match {
+      case '\n' =>
+        ccol = 1;
+        cline = cline + 1;
+      case '\t' =>
+        ccol = ccol + tabinc;
+      case _ =>
+        ccol = ccol + 1;
+    }
+    ch
+  };
+  /** returns true if this source has more characters
+   */
+  def hasNext = iter.hasNext;
+
+  var cline = 1;
+  var ccol = 1;
+  /** position of last character returned by next*/
+  var pos = 0;
+
+  /** the last character returned by next.
+   *  the value before the first call to next is undefined
+   */
+  var ch: Char = _;
+  /** description of this source */
+  var descr:String = "";
+}