JS templates

sdk/lib/_internal/compiler/implementation/js/printer.dart

Index: sdk/lib/_internal/compiler/implementation/js/printer.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js/printer.dart b/sdk/lib/_internal/compiler/implementation/js/printer.dart
index 975cbf6dd43ba44f12bd45edf1f812c0c35fb082..38c9449ba582b223acdaea8a1b7fd30d72c46322 100644
--- a/sdk/lib/_internal/compiler/implementation/js/printer.dart
+++ b/sdk/lib/_internal/compiler/implementation/js/printer.dart
@@ -878,17 +878,24 @@ class Printer implements NodeVisitor {
     outLn(node.code);
   }
 
-  visitJSExpression(JSExpression node) {
-    compiler.internalError(NO_LOCATION_SPANNABLE,
-        'JSPrinter should never see a JSExpression.');
+  visitInterpolatedNode(InterpolatedNode node) {
+    out('#${node.name}');
   }
 
-  visitInterpolatedExpression(InterpolatedExpression node) {
-    visit(node.value);
-  }
+  visitInterpolatedExpression(InterpolatedExpression node) =>
+      visitInterpolatedNode(node);
+
+  visitInterpolatedLiteral(InterpolatedLiteral node) =>
+      visitInterpolatedNode(node);
+
+  visitInterpolatedParameter(InterpolatedParameter node) =>
+      visitInterpolatedNode(node);
+
+  visitInterpolatedSelector(InterpolatedSelector node) =>
+      visitInterpolatedNode(node);
 
   visitInterpolatedStatement(InterpolatedStatement node) {
-    visit(node.value);
+    outLn('#${node.name}');
   }
 
   void visitComment(Comment node) {
@@ -1103,6 +1110,12 @@ class MinifyRenamer implements LocalNamer {
   // use the same namespace for arguments and variables, starting with A, and
   // moving on to a0, a1, etc.
   String declareVariable(String oldName) {
+    // Variables of this $form$ are used in pattern matching the message of JS
+    // exceptions, so should not be renamed.
+    // TODO(sra): Introduce a way for indicating in the JS text which variables
+    // should not be renamed.
+    if (oldName.startsWith(r'$') && oldName.endsWith(r'$')) return oldName;
+
     var newName;
     if (variableNumber + parameterNumber < LOWER_CASE_LETTERS) {
       // Variables start from z and go backwards, for better gzipability.