Cleanup: Some simplifications in json_schema_compiler.

tools/json_schema_compiler/util.h

Index: tools/json_schema_compiler/util.h
diff --git a/tools/json_schema_compiler/util.h b/tools/json_schema_compiler/util.h
index b844dd2882c03137cfa7410504fea566e515aeed..dbd010884502e933b507d5557239359ce020725a 100644
--- a/tools/json_schema_compiler/util.h
+++ b/tools/json_schema_compiler/util.h
@@ -16,26 +16,21 @@ 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()))
@@ -47,14 +42,15 @@ bool GetItemFromList(const base::ListValue& from,
 // 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;
@@ -64,19 +60,13 @@ bool PopulateArrayFromList(
 // 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;
 }
 
@@ -97,7 +87,7 @@ 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(
@@ -110,8 +100,8 @@ void PopulateListFromArray(
   }
 }
 
-// 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,