Simplify line editor choice in d8.

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index 3ef0d54d209cea247cb95499e249c8a3b027b5f8..6d1e9d0be8c801ac8a3bbb017260299dd412f9d8 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -123,44 +123,23 @@ class Symbols {
 };
 
 
-LineEditor *LineEditor::first_ = NULL;
+#ifndef USE_READLINE_CONSOLE
 
+void LineEditor::Open() { }
 
-LineEditor::LineEditor(Type type, const char* name)
-    : type_(type),
-      name_(name),
-      next_(first_) {
-  first_ = this;
-}
-
+LineEditor::~LineEditor() { }
 
-LineEditor* LineEditor::Get() {
-  LineEditor* current = first_;
-  LineEditor* best = current;
-  while (current != NULL) {
-    if (current->type_ > best->type_)
-      best = current;
-    current = current->next_;
-  }
-  return best;
-}
+const char* LineEditor::name() { return "dumb"; }
 
+void LineEditor::AddHistory(const char* str) { }
 
-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_;
-};
-
-
-Handle<String> DumbLineEditor::Prompt(const char* prompt) {
+Handle<String> LineEditor::Prompt(const char* prompt) {
   printf("%s", prompt);
   return Shell::ReadFromStdin(isolate_);
 }
 
+#endif  // USE_READLINE_CONSOLE
+
 
 #ifndef V8_SHARED
 CounterMap* Shell::counter_map_;
@@ -1354,8 +1333,6 @@ int CompareKeys(const void* a, const void* b) {
 
 
 void Shell::OnExit() {
-  LineEditor* line_editor = LineEditor::Get();
-  if (line_editor) line_editor->Close();
 #ifndef V8_SHARED
   if (i::FLAG_dump_counters) {
     int number_of_counters = 0;
@@ -1509,12 +1486,11 @@ void Shell::RunShell(Isolate* isolate) {
   Context::Scope context_scope(evaluation_context_);
   HandleScope outer_scope;
   Handle<String> name = String::New("(d8)");
-  LineEditor* console = LineEditor::Get();
-  printf("V8 version %s [console: %s]\n", V8::GetVersion(), console->name());
-  console->Open();
+  LineEditor console(isolate);
+  printf("V8 version %s [console: %s]\n", V8::GetVersion(), console.name());
   while (true) {
     HandleScope inner_scope;
-    Handle<String> input = console->Prompt(Shell::kPrompt);
+    Handle<String> input = console.Prompt(Shell::kPrompt);
     if (input.IsEmpty()) break;
     ExecuteString(input, name, true, true);
   }
@@ -1913,7 +1889,6 @@ int Shell::Main(int argc, char* argv[]) {
   if (!SetOptions(argc, argv)) return 1;
   int result = 0;
   Isolate* isolate = Isolate::GetCurrent();
-  DumbLineEditor dumb_line_editor(isolate);
   {
     Initialize(isolate);
     Symbols symbols(isolate);