Created Xcode 4 project, using the make target to build the tools, and with a...

Created Xcode 4 project, using the make target to build the tools, and with a native Xcode target to build a hello world example.

mruby/HelloMRuby/hello_mruby.c

+//
+//  hello_mruby.c
+//  mruby
+//
+//  Created by Paolo Bosetti on 5/22/12.
+//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
+//
+
+#include <stdio.h>

xcode/.gitignore

+xcuserdata
\ No newline at end of file

xcode/HelloMRuby/hello_mruby.c

+//
+//  hello_mruby.c
+//  mruby
+//
+//  Created by Paolo Bosetti on 5/22/12.
+//  Copyright (c) 2012 University of Trento. All rights reserved.
+//
+
+#include <stdlib.h>
+#include <stdio.h>
+
+/* Include the mruby header */
+#include <mruby.h>
+#include <mruby/proc.h>
+#include <mruby/data.h>
+#include <mruby/compile.h>
+
+
+
+int main(int argc, const char * argv[])
+{
+  struct mrb_parser_state *parse;
+  mrb_state *mrb = mrb_open();
+  char code[] = "p 'hello world!'";
+  int n;
+
+  printf("Executing Ruby code from C!\n");
+  parse = mrb_parse_string(mrb, code);
+  n = mrb_generate_code(mrb, parse->tree);
+  
+  mrb_run(mrb, mrb_proc_new(mrb, mrb->irep[n]), mrb_top_self(mrb));
+  
+  if (mrb->exc) {
+      mrb_p(mrb, mrb_obj_value(mrb->exc));
+  }
+  
+  mrb_close(mrb);
+  return 0;
+}
\ No newline at end of file

xcode/mruby.xcodeproj/project.xcworkspace/contents.xcworkspacedata

+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:mruby.xcodeproj">
+   </FileRef>
+</Workspace>