1 files changed, 98 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/scratchpad/Mixer.scala b/src/compiler/scala/tools/nsc/scratchpad/Mixer.scala
new file mode 100644
index 0000000000..46ccc32097
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/scratchpad/Mixer.scala
@@ -0,0 +1,98 @@
+package scala.tools.nsc.scratchpad
+
+import java.io.{FileInputStream, InputStreamReader, IOException}
+
+import scala.runtime.ScalaRunTime.stringOf
+import java.lang.reflect.InvocationTargetException
+import scala.reflect.runtime.ReflectionUtils._
+import collection.mutable.ArrayBuffer
+
+class Mixer {
+
+  protected val stdSeparator = "//> "
+  protected val ctdSeparator = "//| "
+  protected val sepColumn = 50
+  protected val tabInc = 8
+
+  type Comments = Seq[(Int, Array[Char])]
+
+  def parseComments(comments: Array[Char]): Iterator[(Int, Array[Char])] = new Iterator[(Int, Array[Char])] {
+    var idx = 0
+    def hasNext = idx < comments.length
+    def next() = {
+      val nextSpace = comments indexOf (' ', idx)
+      var nextNL = comments indexOf ('\n', nextSpace + 1)
+      if (nextNL < 0) nextNL = comments.length
+      val result = 
+        (new String(comments.slice(idx, nextSpace)).toInt, comments.slice(nextSpace + 1, nextNL))
+      idx = nextNL + 1
+      result
+    }
+  }
+
+  def mix(source: Array[Char], comments: Array[Char]): Array[Char] = {
+    val mixed = new ArrayBuffer[Char]
+    var written = 0
+    def align() = {
+      var idx = mixed.lastIndexOf('\n') + 1
+      var col = 0
+      while (idx < mixed.length) {
+        col =
+          if (mixed(idx) == '\t') (col / tabInc) * tabInc + tabInc
+          else col + 1
+        idx += 1
+      }
+      if (col > sepColumn) {
+        mixed += '\n'
+        col = 0
+      }
+      mixed ++= (" " * (sepColumn - col))
+    }
+    for ((offset, cs) <- parseComments(comments)) {
+      val sep =
+        if (written < offset) {
+          for (i <- written until offset) mixed += source(i)
+          written = offset
+          stdSeparator
+        } else {
+          mixed += '\n'
+          ctdSeparator
+        }
+      align()
+      mixed ++= sep ++= cs
+    }
+    mixed ++= source.view(written, source.length)
+    mixed.toArray
+  }
+
+}
+
+object Mixer extends Mixer {
+
+  def contents(name: String): Array[Char] = {
+    val page = new Array[Char](2 << 14)
+    val buf = new ArrayBuffer[Char]
+    val in = new FileInputStream(name)
+    val rdr = new InputStreamReader(in)
+    var nread = 0
+    do {
+      nread = rdr.read(page, 0, page.length)
+      buf ++= (if (nread == page.length) page else page.take(nread))
+    } while (nread >= 0)
+    buf.toArray
+  }
+
+  def main(args: Array[String]) {
+    val mixer = new Mixer
+    try {
+      require(args.length == 2, "required arguments: file1 file2")
+      val source = contents(args(0))
+      val comments = contents(args(1))
+      val mixed = mixer.mix(source, comments)
+      println(mixed.mkString)
+    } catch {
+      case ex: IOException =>
+        println("error: "+ ex.getMessage)
+    }
+  }
+}