Fix for issue 3401: Implement casts in Analyzer

compiler/javatests/com/google/dart/compiler/parser/SyntaxTest.java

Index: compiler/javatests/com/google/dart/compiler/parser/SyntaxTest.java
===================================================================
--- compiler/javatests/com/google/dart/compiler/parser/SyntaxTest.java	(revision 8336)
+++ compiler/javatests/com/google/dart/compiler/parser/SyntaxTest.java	(working copy)
@@ -24,6 +24,7 @@
 import com.google.dart.compiler.ast.DartStringInterpolation;
 import com.google.dart.compiler.ast.DartStringLiteral;
 import com.google.dart.compiler.ast.DartTryStatement;
+import com.google.dart.compiler.ast.DartTypeExpression;
 import com.google.dart.compiler.ast.DartTypeNode;
 import com.google.dart.compiler.ast.DartUnit;
 import com.google.dart.compiler.ast.DartVariableStatement;
@@ -180,6 +181,18 @@
     assertEquals(3, ((DartIntegerLiteral)array.getExpressions().get(2)).getValue().intValue());
   }
 
+  public void testAs() {
+    DartUnit unit = parseUnit("phony_cast.dart", "var x = 3 as int;");
+    List<DartNode> nodes = unit.getTopLevelNodes();
+    assertEquals(1, nodes.size());
+    DartFieldDefinition f = (DartFieldDefinition)nodes.get(0);
+    DartField fieldX = f.getFields().get(0);
+    DartBinaryExpression cast = (DartBinaryExpression) fieldX.getValue();
+    assertTrue(cast.getArg1() instanceof DartIntegerLiteral);
+    assertEquals(Token.AS, cast.getOperator());
+    assertTrue(cast.getArg2() instanceof DartTypeExpression);
+  }
+
   public void testMapLiteral() {
     DartUnit unit = parseUnit("phony_map_literal.dart", "var x = <int>{'a':1,'b':2,'c':3};");
     List<DartNode> nodes = unit.getTopLevelNodes();