Fix a couple of bugs in the REPL.

- Not sure what was going on, but fix #456. It makes more sense for the
  REPL to invoke the compiled code as a fiber than a function anyway.

- Flush stdout before reading from stdin since System.print() no longer
  does that automatically.

src/optional/wren_opt_meta.c

@@ -9,30 +9,23 @@
 
 void metaCompile(WrenVM* vm)
 {
-  // Evaluate the code in the module where the calling function was defined.
-  // That's one stack frame back from the top since the top-most frame is the
-  // helper eval() method in Meta itself.
-  ObjClosure* caller = vm->fiber->frames[vm->fiber->numFrames - 2].closure;
-  ObjModule* module = caller->fn->module;
-
   const char* source = wrenGetSlotString(vm, 1);
   bool isExpression = wrenGetSlotBool(vm, 2);
   bool printErrors = wrenGetSlotBool(vm, 3);
-  
-  // Compile it.
-  ObjFn* fn = wrenCompile(vm, module, source, isExpression, printErrors);
 
+  // TODO: Allow passing in module?
+  ObjFiber* fiber = wrenCompileSource(vm, "main", source,
+                                      isExpression, printErrors);
+  
   // Return the result. We can't use the public API for this since we have a
-  // bare ObjFn.
-  if (fn == NULL)
+  // bare ObjFiber*.
+  if (fiber == NULL)
   {
     vm->apiStack[0] = NULL_VAL;
   }
   else
   {
-    wrenPushRoot(vm, (Obj*)fn);
-    vm->apiStack[0] = OBJ_VAL(wrenNewClosure(vm, fn));
-    wrenPopRoot(vm);
+    vm->apiStack[0] = OBJ_VAL(fiber);
   }
 }
 
@@ -60,7 +53,8 @@ void metaGetModuleVariables(WrenVM* vm) {
   for (int i = 0; i < names->elements.count; i++)
   {
     String* name = &module->variableNames.data[i];
-    names->elements.data[i] = wrenNewString(vm, name->buffer, name->length);
+    names->elements.data[i] = wrenNewStringLength(vm,
+                                                  name->buffer, name->length);
   }
 }
 

src/optional/wren_opt_meta.wren

@@ -10,11 +10,11 @@ class Meta {
   static eval(source) {
     if (!(source is String)) Fiber.abort("Source code must be a string.")
 
-    var fn = compile_(source, false, false)
+    var fiber = compile_(source, false, false)
     // TODO: Include compile errors.
-    if (fn == null) Fiber.abort("Could not compile source code.")
+    if (fiber == null) Fiber.abort("Could not compile source code.")
 
-    Fiber.new(fn).call()
+    fiber.call()
   }
 
   static compileExpression(source) {
@@ -22,6 +22,11 @@ class Meta {
     return compile_(source, true, true)
   }
 
+  static compile(source) {
+    if (!(source is String)) Fiber.abort("Source code must be a string.")
+    return compile_(source, false, true)
+  }
+
   foreign static compile_(source, isExpression, printErrors)
   foreign static getModuleVariables_(module)
 }

src/optional/wren_opt_meta.wren.inc

@@ -12,11 +12,11 @@ static const char* metaModuleSource =
 "  static eval(source) {\n"
 "    if (!(source is String)) Fiber.abort(\"Source code must be a string.\")\n"
 "\n"
-"    var fn = compile_(source, false, false)\n"
+"    var fiber = compile_(source, false, false)\n"
 "    // TODO: Include compile errors.\n"
-"    if (fn == null) Fiber.abort(\"Could not compile source code.\")\n"
+"    if (fiber == null) Fiber.abort(\"Could not compile source code.\")\n"
 "\n"
-"    Fiber.new(fn).call()\n"
+"    fiber.call()\n"
 "  }\n"
 "\n"
 "  static compileExpression(source) {\n"
@@ -24,6 +24,11 @@ static const char* metaModuleSource =
 "    return compile_(source, true, true)\n"
 "  }\n"
 "\n"
+"  static compile(source) {\n"
+"    if (!(source is String)) Fiber.abort(\"Source code must be a string.\")\n"
+"    return compile_(source, false, true)\n"
+"  }\n"
+"\n"
 "  foreign static compile_(source, isExpression, printErrors)\n"
 "  foreign static getModuleVariables_(module)\n"
 "}\n";