A compact tree printer, for primitives like mys...

A compact tree printer, for primitives like myself who do all their
debugging in the console and need extraneous information filtered out.
New option: -Ycompact-trees. Supply that in conjunction with -Xprint:all
and suddenly the output is a (relative) masterpiece of concision. Review
by anyone who is game to review such a thing. Community?

1 files changed, 17 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/TreeInfo.scala b/src/compiler/scala/tools/nsc/ast/TreeInfo.scala
index fd7227c371..aa0e484578 100644
--- a/src/compiler/scala/tools/nsc/ast/TreeInfo.scala
+++ b/src/compiler/scala/tools/nsc/ast/TreeInfo.scala
@@ -350,4 +350,21 @@ abstract class TreeInfo {
     case TypeDef(_, _, _, _) => !isAbsTypeDef(tree)
     case _ => false
   }
+
+  /** Some handy extractors for spotting true and false expressions
+   *  through the haze of braces.
+   */
+  abstract class SeeThroughBlocks[T] {
+    protected def unapplyImpl(x: Tree): T
+    def unapply(x: Tree): T = x match {
+      case Block(Nil, expr)         => unapply(expr)
+      case _                        => unapplyImpl(x)
+    }
+  }
+  object IsTrue extends SeeThroughBlocks[Boolean] {
+    protected def unapplyImpl(x: Tree): Boolean = x equalsStructure Literal(Constant(true))
+  }
+  object IsFalse extends SeeThroughBlocks[Boolean] {
+    protected def unapplyImpl(x: Tree): Boolean = x equalsStructure Literal(Constant(false))
+  }
 }