Add support for command-line editing to ddbg.

tools/ddbg/bin/ddbg.dart

Index: tools/ddbg/bin/ddbg.dart
===================================================================
--- tools/ddbg/bin/ddbg.dart	(revision 0)
+++ tools/ddbg/bin/ddbg.dart	(working copy)
@@ -9,16 +9,20 @@
 import "dart:io";
 import "dart:async";
 
+import "../lib/commando.dart";
 
+
 Map<int, Completer> outstandingCommands;
 
 Socket vmSock;
 String vmData;
-var stdinSubscription;
+Commando cmdo;
 var vmSubscription;
 int seqNum = 0;
 int isolate_id = -1;
 
+Process targetProcess;
+
 final verbose = false;
 final printMessages = false;
 
@@ -60,7 +64,7 @@
 void quitShell() {
   vmSubscription.cancel();
   vmSock.close();
-  stdinSubscription.cancel();
+  cmdo.done();
 }
 
 
@@ -75,6 +79,19 @@
   return completer.future;
 }
 
+
+typedef void HandlerType(response);
+
+HandlerType hidePrompt(void handler(response)) {
+  // Hide the command prompt immediately.
+  cmdo.hide();
+  return (response) {
+    handler(response);
+    cmdo.show();
+  };
+}
+
+
 void processCommand(String cmdLine) {
   
   void huh() {
@@ -82,6 +99,7 @@
   }
 
   seqNum++;
+  cmdLine = cmdLine.trim();
   var args = cmdLine.split(' ');
   if (args.length == 0) {
     return;
@@ -93,17 +111,17 @@
     var cmd = { "id": seqNum,
                 "command": simple_commands[command],
                 "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } else if (command == "bt") {
     var cmd = { "id": seqNum,
                 "command": "getStackTrace",
                 "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleStackTraceResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleStackTraceResponse));
   } else if (command == "ll") {
     var cmd = { "id": seqNum,
                 "command": "getLibraries",
                 "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleGetLibraryResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetLibraryResponse));
   } else if (command == "sbp" && args.length >= 2) {
     var url, line;
     if (args.length == 2 && pausedLocation != null) {
@@ -119,19 +137,19 @@
                 "params": { "isolateId" : isolate_id,
                             "url": url,
                             "line": line }};
-    sendCmd(cmd).then((result) => handleSetBpResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleSetBpResponse));
   } else if (command == "rbp" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "removeBreakpoint",
                 "params": { "isolateId" : isolate_id,
                             "breakpointId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } else if (command == "ls" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "getScriptURLs",
                 "params": { "isolateId" : isolate_id,
                             "libraryId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetScriptsResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetScriptsResponse));
   } else if (command == "eval" && args.length > 3) {
     var expr = args.getRange(3, args.length).join(" ");
     var target = args[1];
@@ -150,83 +168,83 @@
                 "params": { "isolateId": isolate_id,
                             target: int.parse(args[2]),
                             "expression": expr } };
-    sendCmd(cmd).then((result) => handleEvalResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleEvalResponse));
   } else if (command == "po" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "getObjectProperties",
                 "params": { "isolateId" : isolate_id,
                             "objectId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetObjPropsResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetObjPropsResponse));
   } else if (command == "pl" && args.length >= 3) {
-     var cmd;
-     if (args.length == 3) {
-       cmd = { "id": seqNum,
-               "command": "getListElements",
-               "params": { "isolateId" : isolate_id,
-                           "objectId": int.parse(args[1]),
-                           "index": int.parse(args[2]) } };
+    var cmd;
+    if (args.length == 3) {
+      cmd = { "id": seqNum,
+              "command": "getListElements",
+              "params": { "isolateId" : isolate_id,
+                          "objectId": int.parse(args[1]),
+                          "index": int.parse(args[2]) } };
     } else {
-       cmd = { "id": seqNum,
-               "command": "getListElements",
-               "params": { "isolateId" : isolate_id,
-                           "objectId": int.parse(args[1]),
-                           "index": int.parse(args[2]),
-                           "length": int.parse(args[3]) } };
+      cmd = { "id": seqNum,
+              "command": "getListElements",
+              "params": { "isolateId" : isolate_id,
+                          "objectId": int.parse(args[1]),
+                          "index": int.parse(args[2]),
+                          "length": int.parse(args[3]) } };
     }
-    sendCmd(cmd).then((result) => handleGetListResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetListResponse));
   } else if (command == "pc" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "getClassProperties",
                 "params": { "isolateId" : isolate_id,
                             "classId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetClassPropsResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetClassPropsResponse));
   } else if (command == "plib" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "getLibraryProperties",
                 "params": {"isolateId" : isolate_id,
                            "libraryId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetLibraryPropsResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetLibraryPropsResponse));
   } else if (command == "slib" && args.length == 3) {
     var cmd = { "id": seqNum,
                 "command": "setLibraryProperties",
                 "params": {"isolateId" : isolate_id,
                            "libraryId": int.parse(args[1]),
                            "debuggingEnabled": args[2] } };
-    sendCmd(cmd).then((result) => handleSetLibraryPropsResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleSetLibraryPropsResponse));
   } else if (command == "pg" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "getGlobalVariables",
                 "params": { "isolateId" : isolate_id,
                             "libraryId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetGlobalVarsResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetGlobalVarsResponse));
   } else if (command == "gs" && args.length == 3) {
     var cmd = { "id": seqNum,
                 "command":  "getScriptSource",
                 "params": { "isolateId" : isolate_id,
                             "libraryId": int.parse(args[1]),
                             "url": args[2] } };
-    sendCmd(cmd).then((result) => handleGetSourceResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetSourceResponse));
   } else if (command == "tok" && args.length == 3) {
     var cmd = { "id": seqNum,
                 "command":  "getLineNumberTable",
                 "params": { "isolateId" : isolate_id,
                             "libraryId": int.parse(args[1]),
                             "url": args[2] } };
-    sendCmd(cmd).then((result) => handleGetLineTableResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetLineTableResponse));
   } else if (command == "epi" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command":  "setPauseOnException",
                 "params": { "isolateId" : isolate_id,
                             "exceptions": args[1] } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } else if (command == "li") {
     var cmd = { "id": seqNum, "command": "getIsolateIds" };
-    sendCmd(cmd).then((result) => handleGetIsolatesResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetIsolatesResponse));
   } else if (command == "i" && args.length == 2) {
     var cmd = { "id": seqNum,
                 "command": "interrupt",
                 "params": { "isolateId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } else if (command == "q") {
     quitShell();
   } else if (command == "h") {
@@ -366,7 +384,7 @@
 }
 
 
-handleGetIsolatesResponse(response) {
+void handleGetIsolatesResponse(response) {
   Map result = response["result"];
   print("Isolates: ${result["isolateIds"]}");
 }
@@ -470,32 +488,39 @@
   }
   var event = msg["event"];
   if (event == "paused") {
+    cmdo.hide();
     handlePausedEvent(msg);
+    cmdo.show();
     return;
   }
   if (event == "breakpointResolved") {
     Map params = msg["params"];
     assert(params != null);
+    cmdo.hide();
     print("BP ${params["breakpointId"]} resolved and "
           "set at line ${params["line"]}.");
+    cmdo.show();
     return;
   }
   if (event == "isolate") {
     Map params = msg["params"];
     assert(params != null);
+    cmdo.hide();
     print("Isolate ${params["id"]} has been ${params["reason"]}.");
+    cmdo.show();
     return;
   }
   if (msg["id"] != null) {
     var id = msg["id"];
     if (outstandingCommands.containsKey(id)) {
+      var completer = outstandingCommands.remove(id);
       if (msg["error"] != null) {
         print("VM says: ${msg["error"]}");
+        // TODO(turnidge): Rework how hide/show happen.  For now
+        cmdo.show();
       } else {
-        var completer = outstandingCommands[id];
         completer.complete(msg);
       }
-      outstandingCommands.remove(id);
     }
   }
 }
@@ -600,7 +625,31 @@
   return 0;
 }
 
+List<String> debuggerCommandCompleter(List<String> commandParts) {
+  List<String> completions = new List<String>();
 
+  // TODO(turnidge): Have a global command table and use it to for
+  // help messages, command completion, and command dispatching.  For now
+  // we hardcode the list here.
+  //
+  // TODO(turnidge): Implement completion for arguments as well.
+  List<String> allCommands = ['q', 'bt', 'r', 's', 'so', 'si', 'sbp', 'rbp',
+                              'po', 'eval', 'pl', 'pc', 'll', 'plib', 'slib',
+                              'pg', 'ls', 'gs', 'tok', 'epi', 'li', 'i', 'h'];
+
+  // Completion of first word in the command.
+  if (commandParts.length == 1) {
+    String prefix = commandParts.last;
+    for (String command in allCommands) {
+      if (command.startsWith(prefix)) {
+        completions.add(command);
+      }
+    } 
+  }
+
+  return completions;
+}
+
 void debuggerMain() {
   outstandingCommands = new Map<int, Completer>();
   Socket.connect("127.0.0.1", 5858).then((s) {
@@ -620,20 +669,46 @@
           // TODO(floitsch): do we want to print the stack trace?
           quitShell();
         });
-    stdinSubscription = stdin.transform(UTF8.decoder)
-                             .transform(new LineSplitter())
-                             .listen((String line) => processCommand(line));
+    cmdo = new Commando(stdin, stdout, processCommand,
+                        completer:debuggerCommandCompleter);
   });
 }
 
-void main(List<String> arguments) {
-  if (arguments.length > 0) {
-    arguments = <String>['--debug', '--verbose_debug']..addAll(arguments);
-    Process.start(Platform.executable, arguments).then((Process process) {
-      process.stdin.close();
-      process.exitCode.then((int exitCode) {
-        print('${arguments.join(" ")} exited with $exitCode');
-      });
+void main(List<String> args) {
+  if (args.length > 0) {
+    if (verbose) {
+      args = <String>['--debug', '--verbose_debug']..addAll(args);
+    } else {
+      args = <String>['--debug']..addAll(args);
+    }
+    Process.start(Platform.executable, args).then((Process process) {
+        targetProcess = process;
+        process.stdin.close();
+
+        // TODO(turnidge): For now we only show full lines of output
+        // from the debugged process.  Should show each character.
+        process.stdout
+            .transform(UTF8.decoder)
+            .transform(new LineSplitter())
+            .listen((String line) {
+                // Hide/show command prompt across asynchronous output.
+                if (cmdo != null) {
+                  cmdo.hide();
+                }
+                print("$line");
+                if (cmdo != null) {
+                  cmdo.show();
+                }
+              });
+
+        process.exitCode.then((int exitCode) {
+            if (exitCode == 0) {
+              print('Program exited normally.');
+            } else {
+              print('Program exited with code $exitCode.');
+            }
+          });
+
       debuggerMain();
     });
   } else {