Cleanup: Some simplifications in json_schema_compiler.

tools/json_schema_compiler/util.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef TOOLS_JSON_SCHEMA_COMPILER_UTIL_H__
 #define TOOLS_JSON_SCHEMA_COMPILER_UTIL_H__
 
 #include <string>
 #include <vector>
 
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 
 namespace json_schema_compiler {
 
 namespace util {
 
-// Creates a new item at |out| from |from|[|index|]. These are used by template
+// Populates the item |out| from the value |from|. These are used by template
 // specializations of |Get(Optional)ArrayFromList|.
-bool GetItemFromList(const base::ListValue& from, int index, int* out);
-bool GetItemFromList(const base::ListValue& from, int index, bool* out);
-bool GetItemFromList(const base::ListValue& from, int index, double* out);
-bool GetItemFromList(const base::ListValue& from, int index, std::string* out);
-bool GetItemFromList(const base::ListValue& from,
-                     int index,
-                     linked_ptr<base::Value>* out);
-bool GetItemFromList(const base::ListValue& from,
-                     int index,
-                     linked_ptr<base::DictionaryValue>* out);
+bool PopulateItem(const base::Value& from, int* out);
+bool PopulateItem(const base::Value& from, bool* out);
+bool PopulateItem(const base::Value& from, double* out);
+bool PopulateItem(const base::Value& from, std::string* out);
+bool PopulateItem(const base::Value& from, linked_ptr<base::Value>* out);
+bool PopulateItem(const base::Value& from,
+                  linked_ptr<base::DictionaryValue>* out);
 
 // This template is used for types generated by tools/json_schema_compiler.
-template<class T>
-bool GetItemFromList(const base::ListValue& from,
-                     int index,
-                     linked_ptr<T>* out) {
-  const base::DictionaryValue* dict;
-  if (!from.GetDictionary(index, &dict))
+template <class T>
+bool PopulateItem(const base::Value& from, linked_ptr<T>* out) {
+  const base::DictionaryValue* dict = nullptr;
+  if (!from.GetAsDictionary(&dict))
     return false;
   scoped_ptr<T> obj(new T());
   if (!T::Populate(*dict, obj.get()))
     return false;
   *out = linked_ptr<T>(obj.release());
   return true;
 }
 
 // Populates |out| with |list|. Returns false if there is no list at the
 // specified key or if the list has anything other than |T|.
 template <class T>
-bool PopulateArrayFromList(
-    const base::ListValue& list, std::vector<T>* out) {
+bool PopulateArrayFromList(const base::ListValue& list,
+                           std::vector<T>* out) {
   out->clear();
-  T value;
+  T item;
   for (size_t i = 0; i < list.GetSize(); ++i) {

[not at google - send to devlin, 2015/01/15 20:47:30]

I notice that ListValue has an iterator-like interface with begin() and end(), I
wonder if the (const base::Value* value : list) syntax works here? That'd be
simpler. There's no way that "list.Get(i, &value)" should ever be able to fail.

[pneubeck (no reviews), 2015/01/16 08:20:13]

Yes, forgot about that.
Did the same to the other for loop below.

-    if (!GetItemFromList(list, i, &value))
+    const base::Value* value = nullptr;
+    if (!list.Get(i, &value) || !PopulateItem(*value, &item))
       return false;
-    out->push_back(value);
+    out->push_back(item);
   }
 
   return true;
 }
 
 // Creates a new vector containing |list| at |out|. Returns
 // true on success or if there is nothing at the specified key. Returns false
 // if anything other than a list of |T| is at the specified key.
 template <class T>
-bool PopulateOptionalArrayFromList(
-    const base::ListValue& list,
-    scoped_ptr<std::vector<T> >* out) {
+bool PopulateOptionalArrayFromList(const base::ListValue& list,
+                                   scoped_ptr<std::vector<T>>* out) {
   out->reset(new std::vector<T>());
-  T value;
-  for (size_t i = 0; i < list.GetSize(); ++i) {
-    if (!GetItemFromList(list, i, &value)) {
-      out->reset();
-      return false;
-    }
-    (*out)->push_back(value);
+  if (!PopulateArrayFromList(list, out->get())) {
+    out->reset();
+    return false;
   }
-
   return true;
 }
 
 // Appends a Value newly created from |from| to |out|. These used by template
 // specializations of |Set(Optional)ArrayToList|.
 void AddItemToList(const int from, base::ListValue* out);
 void AddItemToList(const bool from, base::ListValue* out);
 void AddItemToList(const double from, base::ListValue* out);
 void AddItemToList(const std::string& from, base::ListValue* out);
 void AddItemToList(const linked_ptr<base::Value>& from,
                    base::ListValue* out);
 void AddItemToList(const linked_ptr<base::DictionaryValue>& from,
                    base::ListValue* out);
 
 // This template is used for types generated by tools/json_schema_compiler.
 template<class T>
 void AddItemToList(const linked_ptr<T>& from, base::ListValue* out) {
   out->Append(from->ToValue().release());
 }
 
-// Set |out| to the the contents of |from|. Requires GetItemFromList to be
+// Set |out| to the the contents of |from|. Requires PopulateItem to be
 // implemented for |T|.
 template <class T>
 void PopulateListFromArray(
     const std::vector<T>& from,
     base::ListValue* out) {
   out->Clear();
   for (typename std::vector<T>::const_iterator it = from.begin();
       it != from.end(); ++it) {
     AddItemToList(*it, out);
   }
 }
 
-// Set |out| to the the contents of |from| if |from| is non-NULL. Requires
-// GetItemFromList to be implemented for |T|.
+// Set |out| to the the contents of |from| if |from| is not null. Requires
+// PopulateItem to be implemented for |T|.
 template <class T>
 void PopulateListFromOptionalArray(
     const scoped_ptr<std::vector<T> >& from,
     base::ListValue* out) {
   if (from.get())
     PopulateListFromArray(*from, out);
 
 }
 
 template <class T>
@@ skipping 10 matching lines @@
     return CreateValueFromArray(*from);
   return scoped_ptr<base::Value>();
 }
 
 std::string ValueTypeToString(base::Value::Type type);
 
 }  // namespace util
 }  // namespace json_schema_compiler
 
 #endif // TOOLS_JSON_SCHEMA_COMPILER_UTIL_H__