New Context architecture based on cloning

1 files changed, 55 insertions, 2 deletions

diff --git a/src/dotty/tools/dotc/core/Printers.scala b/src/dotty/tools/dotc/core/Printers.scala
index 67d4d3422..d7476c433 100644
--- a/src/dotty/tools/dotc/core/Printers.scala
+++ b/src/dotty/tools/dotc/core/Printers.scala
@@ -3,8 +3,28 @@ package core
 
 import Types._, Symbols._, Contexts._, Scopes._
 
+trait Printers {
+
+  private[this] var _diagnostics: Option[StringBuilder] = _
+  protected def diagnostics_=(diagnostics: Option[StringBuilder]) = _diagnostics = diagnostics
+  def diagnostics: Option[StringBuilder] = _diagnostics
+
+  def diagnose(str: => String) =
+    for (sb <- diagnostics) {
+      sb.setLength(0)
+      sb.append(str)
+    }
+}
+
+
 object Printers {
 
+  trait PrinterBase { self: ContextBase =>
+
+    private[core] var showRecursions = 0
+
+  }
+
   abstract class Printer {
     def show(tp: Type)(implicit ctx: Context): String
     def show(sym: Symbol)(implicit ctx: Context): String
@@ -13,9 +33,41 @@ object Printers {
     def show(sc: Scope)(implicit ctx: Context): String
   }
 
+  object StdPrinter {
+    final val maxShowRecursions = 50
+  }
+
   class StdPrinter extends Printer {
-    def show(tp: Type)(implicit ctx: Context): String = ???
-    def show(sym: Symbol)(implicit ctx: Context): String = ???
+    import StdPrinter._
+
+    def controlled(op: => String)(implicit ctx: Context): String =
+      if (ctx.showRecursions < maxShowRecursions)
+        try {
+          ctx.showRecursions += 1
+          op
+        } finally {
+          ctx.showRecursions -= 1
+        }
+      else {
+        if (???/*ctx.settings.debug.value*/) {
+          ctx.warning("Exceeded recursion depth attempting to print type.")
+          (new Throwable).printStackTrace
+        }
+        "..."
+      }
+
+    def show(tp: Type)(implicit ctx: Context): String = controlled {
+      tp match {
+        case TermRef(pre, name) =>
+          ??? // showPrefix(pre) + show(name)
+
+
+
+      }
+    }
+    def show(sym: Symbol)(implicit ctx: Context): String = controlled {
+      ???
+    }
     def showLocated(sym: Symbol)(implicit ctx: Context): String = ???
     def showDef(sym: Symbol)(implicit ctx: Context): String = ???
     def show(sc: Scope)(implicit ctx: Context): String =
@@ -23,4 +75,5 @@ object Printers {
   }
 
 
+
 }
\ No newline at end of file