fix analyzer warnings and hints

found this with:
$ dartanalyzer --fatal-warnings --package-warnings bin/devc.dart | (! grep $PWD)

[email protected], [email protected]

Review URL: https://chromereviews.googleplex.com/147897013

Author: John Messerly

lib/src/checker/rules.dart

@@ -253,15 +253,15 @@ class RestrictedRules extends TypeRules {
 
     // "Traditional" name-based subtype check.
     if (t1 is InterfaceType && t2 is InterfaceType) {
-      return _isInterfaceSubTypeOf(t1 as InterfaceType, t2 as InterfaceType);
+      return _isInterfaceSubTypeOf(t1, t2);
     }
 
     if (t1 is! FunctionType && t2 is! FunctionType) return false;
 
     if (t1 is InterfaceType && t2 is FunctionType) {
       var callType = getCallMethodType(t1);
       if (callType == null) return false;
-      return isFunctionSubTypeOf(callType, t2 as FunctionType);
+      return isFunctionSubTypeOf(callType, t2);
     }
 
     if (t1 is FunctionType && t2 is InterfaceType) {

lib/src/codegen/ast_builder.dart

@@ -117,7 +117,6 @@ class AstBuilder {
   static FunctionExpression expressionFunction(
       List<FormalParameter> params, Expression body, [bool decl = false]) {
     FormalParameterList fl = formalParameterList(params);
-    Token semi = (decl) ? new Token(TokenType.SEMICOLON, 0) : null;
     ExpressionFunctionBody b = RawAstBuilder.expressionFunctionBody(body, decl);
     return RawAstBuilder.functionExpression(fl, b);
   }

lib/src/codegen/code_generator.dart

@@ -4,7 +4,6 @@ import 'dart:async' show Future;
 import 'dart:io';
 
 import 'package:analyzer/src/generated/ast.dart' show CompilationUnit;
-import 'package:analyzer/src/generated/element.dart';
 import 'package:path/path.dart' as path;
 
 import 'package:ddc/src/info.dart';

lib/src/codegen/js_codegen.dart

@@ -297,7 +297,6 @@ var $libName;
   void _initializeFields(List<FieldDeclaration> fields,
       [FormalParameterList parameters,
       NodeList<ConstructorInitializer> initializers]) {
-    var initialized = new Set<String>();
 
     // Run field initializers if they can have side-effects.
     var unsetFields = new Map<String, Expression>();
@@ -1104,8 +1103,3 @@ class JSGenerator extends CodeGenerator {
     return new UnitGenerator(unit, libraryDir, info, rules).generate();
   }
 }
-
-class _Property {
-  MethodDeclaration getter;
-  MethodDeclaration setter;
-}

lib/src/codegen/reify_coercions.dart

@@ -421,7 +421,7 @@ class TypeManager {
       var tpl = alias.typeParameters;
       if (tpl != null) {
         var ltp = tpl.typeParameters;
-        var ts = ltp.map((t) => AstBuilder.typeName(t.name, null));
+        ts = ltp.map((t) => AstBuilder.typeName(t.name, null));
       }
       var name = alias.name;
       return AstBuilder.typeName(name, ts);