Make scoping more prominent in the CPS IR's printed representation.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.ir_nodes_sexpr;
 
 import '../constants/values.dart';
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 
@@ skipping 43 matching lines @@
     String body = indentBlock(() => visit(node.body.body));
     return '$indentation(FunctionDefinition $name ($parameters) return'
         ' ($closureVariables)\n$body)';
   }
 
   String visitFieldDefinition(FieldDefinition node) {
     String name = node.element.name;
     if (node.hasInitializer) {
       namer.setReturnContinuation(node.body.returnContinuation);
       String body = indentBlock(() => visit(node.body.body));
-      return '$indentation(FieldDefinition $name (return)\n'
+      return '$indentation(FieldDefinition $name () return\n'
              '$body)';
     } else {
       return '$indentation(FieldDefinition $name)';
     }
   }
 
   String visitLetPrim(LetPrim node) {
     String name = newValueName(node.primitive);
     String value = visit(node.primitive);
-    String body = visit(node.body);
-    return '$indentation(LetPrim $name $value)\n$body';
+    String body = indentBlock(() => visit(node.body));
+    return '$indentation(LetPrim ($name $value)\n$body)';
   }
 
   String visitLetCont(LetCont node) {
     String cont = newContinuationName(node.continuation);
     // TODO(karlklose): this should be changed to `.map(visit).join(' ')`  and
     // should recurse to [visit].  Currently we can't do that, because the
     // unstringifier_test produces [LetConts] with dummy arguments on them.
     String parameters = node.continuation.parameters
-        .map((p) => ' ${decorator(p, newValueName(p))}')
-        .join('');
-    String contBody = indentBlock(() => visit(node.continuation.body));
-    String body = visit(node.body);
+        .map((p) => '${decorator(p, newValueName(p))}')
+        .join(' ');
+    String contBody =
+        indentBlock(() => indentBlock(() => visit(node.continuation.body)));

[Kevin Millikin (Google), 2015/01/06 08:01:52]

I'd actually like to align these bodies, but that's not so easy.  As a hack, I'm
indenting them twice this way.

+    String body = indentBlock(() => visit(node.body));
     String op = node.continuation.isRecursive ? 'LetCont*' : 'LetCont';
-    return '$indentation($op ($cont$parameters)\n'
+    return '$indentation($op ($cont ($parameters)\n'
            '$contBody)\n'
-           '$body';
+           '$body)';
   }
 
   String formatArguments(Invoke node) {
     int positionalArgumentCount = node.selector.positionalArgumentCount;
     List<String> args = new List<String>();
     args.addAll(
         node.arguments.getRange(0, positionalArgumentCount).map(access));
     for (int i = 0; i < node.selector.namedArgumentCount; ++i) {
       String name = node.selector.namedArguments[i];
       Definition arg = node.arguments[positionalArgumentCount + i].definition;
       args.add("($name: $arg)");
     }
-    return args.join(' ');
+    return '(${args.join(' ')})';
   }
 
   String visitInvokeStatic(InvokeStatic node) {
     String name = node.target.name;
     String cont = access(node.continuation);
     String args = formatArguments(node);
     return '$indentation(InvokeStatic $name $args $cont)';
   }
 
   String visitInvokeMethod(InvokeMethod node) {
@@ skipping 19 matching lines @@
       callName = '${node.type}.${node.target.name}';
     }
     String cont = access(node.continuation);
     String args = formatArguments(node);
     return '$indentation(InvokeConstructor $callName $args $cont)';
   }
 
   String visitConcatenateStrings(ConcatenateStrings node) {
     String cont = access(node.continuation);
     String args = node.arguments.map(access).join(' ');
-    return '$indentation(ConcatenateStrings $args $cont)';
+    return '$indentation(ConcatenateStrings ($args) $cont)';
   }
 
   String visitInvokeContinuation(InvokeContinuation node) {
     String cont = access(node.continuation);
     String args = node.arguments.map(access).join(' ');
     String op =
         node.isRecursive ? 'InvokeContinuation*' : 'InvokeContinuation';
-    return '$indentation($op $cont $args)';
+    return '$indentation($op $cont ($args))';
   }
 
   String visitBranch(Branch node) {
     String condition = visit(node.condition);
     String trueCont = access(node.trueContinuation);
     String falseCont = access(node.falseContinuation);
     return '$indentation(Branch $condition $trueCont $falseCont)';
   }
 
   String visitConstant(Constant node) {
     String value =
         node.expression.value.accept(new ConstantStringifier(), null);
     return '(Constant $value)';
   }
 
   String visitThis(This node) {
     return '(This)';
   }
 
   String visitReifyTypeVar(ReifyTypeVar node) {
     return '$indentation(ReifyTypeVar ${node.typeVariable.name})';
   }
 
   String visitCreateFunction(CreateFunction node) {
-    String function = indentBlock(() => visit(node.definition));
+    String function =
+        indentBlock(() => indentBlock(() => visit(node.definition)));
     return '(CreateFunction\n$function)';
   }
 
   String visitContinuation(Continuation node) {
     // Continuations are visited directly in visitLetCont.
     return '(Unexpected Continuation)';
   }
 
   String visitGetClosureVariable(GetClosureVariable node) {
     return '(GetClosureVariable ${visit(node.variable.definition)})';
@@ skipping 141 matching lines @@
   void setReturnContinuation(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     _names[node] = 'return';
   }
 
   String getName(Node node) {
     assert(_names.containsKey(node));
     return _names[node];
   }
 }