Simplify line editor choice in d8.

src/d8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 105 matching lines @@
 #undef DEFINE_SYMBOL_GETTER
 
  private:
   Isolate* isolate_;
 #define DEFINE_MEMBER(name, value) Persistent<String> name##_;
   FOR_EACH_SYMBOL(DEFINE_MEMBER)
 #undef DEFINE_MEMBER
 };
 
 
-LineEditor *LineEditor::first_ = NULL;
+LineEditor *LineEditor::current_ = NULL;
 
 
 LineEditor::LineEditor(Type type, const char* name)
-    : type_(type),
-      name_(name),
-      next_(first_) {
-  first_ = this;
+    : type_(type), name_(name) {
+  if (current_ == NULL || current_->type_ < type) current_ = this;

[rossberg, 2013/02/27 16:32:48]

Shouldn't you perhaps delete the current current_ here?

[Yang, 2013/02/28 12:59:57]

Would that be safe? Both DumbLineEditor and ReadLineEditor are stack allocated.
Besides, deleting would only make sense if the DumbLineEditor happens to be
constructed first. Otherwise both would stay alive.

 }
 
 
-LineEditor* LineEditor::Get() {
-  LineEditor* current = first_;
-  LineEditor* best = current;
-  while (current != NULL) {
-    if (current->type_ > best->type_)
-      best = current;
-    current = current->next_;
-  }
-  return best;
-}
-
-
 class DumbLineEditor: public LineEditor {
  public:
   explicit DumbLineEditor(Isolate* isolate)
       : LineEditor(LineEditor::DUMB, "dumb"), isolate_(isolate) { }
   virtual Handle<String> Prompt(const char* prompt);
  private:
   Isolate* isolate_;
 };
 
 
@@ skipping 1817 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif