1 files changed, 57 insertions, 0 deletions
diff --git a/compiler/src/dotty/tools/dotc/util/SourcePosition.scala b/compiler/src/dotty/tools/dotc/util/SourcePosition.scala
new file mode 100644
index 000000000..aad4995d8
--- /dev/null
+++ b/compiler/src/dotty/tools/dotc/util/SourcePosition.scala
@@ -0,0 +1,57 @@
+package dotty.tools
+package dotc
+package util
+
+import Positions.{Position, NoPosition}
+
+/** A source position is comprised of a position in a source file */
+case class SourcePosition(source: SourceFile, pos: Position, outer: SourcePosition = NoSourcePosition)
+extends interfaces.SourcePosition {
+  def exists = pos.exists
+
+  def lineContent: String = source.lineContent(point)
+
+  def point: Int = pos.point
+  /** The line of the position, starting at 0 */
+  def line: Int = source.offsetToLine(point)
+
+  /** The lines of the position */
+  def lines: List[Int] =
+    List.range(source.offsetToLine(start), source.offsetToLine(end + 1)) match {
+      case Nil => line :: Nil
+      case xs => xs
+    }
+
+  def lineOffsets: List[Int] =
+    lines.map(source.lineToOffset(_))
+
+  def lineContent(lineNumber: Int): String =
+    source.lineContent(source.lineToOffset(lineNumber))
+
+  def beforeAndAfterPoint: (List[Int], List[Int]) =
+    lineOffsets.partition(_ <= point)
+
+  /** The column of the position, starting at 0 */
+  def column: Int = source.column(point)
+
+  def start: Int = pos.start
+  def startLine: Int = source.offsetToLine(start)
+  def startColumn: Int = source.column(start)
+
+  def end: Int = pos.end
+  def endLine: Int = source.offsetToLine(end)
+  def endColumn: Int = source.column(end)
+
+  def withOuter(outer: SourcePosition) = new SourcePosition(source, pos, outer)
+
+  override def toString =
+    if (source.exists) s"${source.file}:${line + 1}"
+    else s"(no source file, offset = ${pos.point})"
+}
+
+/** A sentinel for a non-existing source position */
+@sharable object NoSourcePosition extends SourcePosition(NoSource, NoPosition) {
+  override def toString = "?"
+  override def withOuter(outer: SourcePosition) = outer
+}
+