cleanup errors and fix a couple field negative tests

frog/library.dart

 // Copyright (c) 2011, 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.
 
 class LibraryImport {
   String prefix;
   Library library;
   LibraryImport(this.library, [this.prefix = null]);
 }
 
@@ skipping 158 matching lines @@
     for (var imported in imports) {
       var newRet = null;
       if (imported.prefix == null) {
         newRet = imported.library.types[name];
       } else if (imported.prefix == name) {
         newRet = imported.library.topType;
       }
       if (newRet != null) {
         // TODO(jimhug): Should not need ret != newRet here or below.
         if (ret != null  && ret != newRet) {
-          world.error('conflicting types for "$name"', ret.span);
-          world.error('conflicting types for "$name"', newRet.span);
+          world.error('conflicting types for "$name"', ret.span, newRet.span);
         } else {
           ret = newRet;
         }
       }
     }
     return ret;
   }
 
   Member lookup(String name, SourceSpan span) {
     var retType = findTypeByName(name);
     var ret = null;
 
     if (retType != null) {
       ret = retType.typeMember;
     }
 
     var newRet = topType.getMember(name);
     // TODO(jimhug): Shares too much code with body of loop.
     if (newRet != null) {
       if (ret != null && ret != newRet) {
-        world.error('conflicting members for "$name"', span);
-        world.error('conflicting members for "$name"', ret.span);
-        world.error('conflicting members for "$name"', newRet.span);
+        world.error('conflicting members for "$name"',
+          span, ret.span, newRet.span);
       } else {
         ret = newRet;
       }
     }
 
     // Check all imports even if ret != null to detect conflicting names.
     // TODO(jimhug): Only do this on first lookup.
     for (var imported in imports) {
       if (imported.prefix == null) {
         newRet = imported.library.topType.getMember(name);
         if (newRet != null) {
           if (ret != null && ret != newRet) {
-            world.error('conflicting members for "$name"', span);
-            world.error('conflicting members for "$name"', ret.span);
-            world.error('conflicting members for "$name"', newRet.span);
+            world.error('conflicting members for "$name"',
+              span, ret.span, newRet.span);
           } else {
             ret = newRet;
           }
         }
       }
     }
     return ret;
   }
 
   resolve() {
@@ skipping 118 matching lines @@
 
         var filename = library.makeFullPath(name);
 
         if (library.imports.some((li) => li.library.baseSource == filename)) {
           // TODO(jimhug): Can you import a lib twice with different prefixes?
           world.error('duplicate import of "$name"', node.span);
           return;
         }
 
         var newLib = library.addImport(filename, prefix);
-        if (newLib.name == null && !filename.startsWith('dart:')) {
-          world.info('imported library "$name" has no #library directive',
-            node.span);
-        }
+        // TODO(jimhug): Add check that imported library has a #library
         break;
 
       case "source":
         seenSource = true;
         name = getSingleStringArg(node);
         addSourceFromName(name, node.span);
         if (seenResource) {
           world.error('#sources must come before any #resource', node.span);
         }
         break;
@@ skipping 78 matching lines @@
 
   void visitFunctionDefinition(FunctionDefinition node) {
     currentType.addMethod(node.name.name, node);
   }
 
   void visitFunctionTypeDefinition(FunctionTypeDefinition node) {
     var type = library.addType(node.func.name.name, node, false);
     type.addMethod('\$call', node.func);
   }
 }