C++ compiler.

Rely on the new mbed repository rather than hardcode a lot of C++ in
TouchDevelop.

editor/external.ts

@@ -83,23 +83,6 @@ module TDev {
             });
         }
 
-        var cppPrelude =
-            '#include "mbed.h"\n'+
-            '#include <string>\n'+
-            'DigitalOut led2(LED2), led1(LED1);\n'+
-            'Serial pc(USBTX, USBRX);\n'+
-            'typedef void (*callback)();\n'+
-            'void microbit_register(const string& event, callback f) {\n'+
-            '    if (event == "start")\n'+
-            '        f();\n'+
-            '}\n'+
-            'void microbit_set_led(int led, int val) {\n'+
-            '    if (led == 2)\n'+
-            '        led2 = val;\n'+
-            '    else if (led == 1)\n'+
-            '        led1 = val;\n'+
-            '}\n';
-
         export class Channel {
             constructor(
                 private editor: ExternalEditor,
@@ -234,7 +217,7 @@ module TDev {
                         }
                         cpp.then((cpp: string) => {
                             console.log(cpp);
-                            cpp = cppPrelude + cpp;
+                            cpp = "#include \"prelude.h\"\n" + cpp;
                             Cloud.postUserInstalledCompileAsync(this.guid, cpp).then(json => {
                                 // Success.
                                 console.log(json);

editor/microbit/emitter.ts

@@ -32,7 +32,7 @@ module TDev {
 
     var knownMicrobitCalls: { [index: string]: string } = {
       "on": "microbit_register",
-      "wait": "wait",
+      "wait": "wait_ms",
       "set led": "microbit_set_led",
     };
 
@@ -53,6 +53,13 @@ module TDev {
       }
 
       public visitLocalRef(env: EmitterEnv, name: string, id: string) {
+        // In our translation, referring to a TouchDevelop identifier never
+        // requires adding a reference operator (&). Things passed by reference
+        // are either:
+        // - function pointers (a.k.a. "handlers" in TouchDevelop lingo), for
+        //   which C and C++ accept both "f" and "&f" (we hence use the former)
+        // - arrays, strings, user-defined objects, which are in fact of type
+        //   "shared_ptr<T>", no "&" operator here.
         return H.mangle(name, id);
       }
 
@@ -95,7 +102,7 @@ module TDev {
             throw "Unknown microbit call: "+name;
           return mkCall(knownMicrobitCalls[name]);
         } else if (name == ":=") {
-          return this.visit(env, receiver) + " = " + this.visit(env, args[0]);
+          return this.visit(env, receiver) + " = " + argsCode[0];
         } else {
           throw "Unknown call "+name;
         }