fix #30 and add #19 sys.stdin, sys.stdout, sys.stderr (#32)

lib/sys.py

@@ -14,8 +14,8 @@
 
 """System-specific parameters and functions."""
 
-from __go__.os import Args
-from __go__.grumpy import SysModules, MaxInt  # pylint: disable=g-multiple-import
+from __go__.os import Args, Stdin, Stdout, Stderr
+from __go__.grumpy import SysModules, MaxInt, NewFileFromFD  # pylint: disable=g-multiple-import
 from __go__.runtime import Version
 
 argv = []
@@ -28,6 +28,10 @@ modules = SysModules
 py3kwarning = False
 warnoptions = []
 
+stdin  =  NewFileFromFD(Stdin.Fd())
+stdout =  NewFileFromFD(Stdout.Fd())
+stderr =  NewFileFromFD(Stderr.Fd())
+
 
 class _Flags(object):
   """Container class for sys.flags."""

runtime/file.go

@@ -44,7 +44,9 @@ type File struct {
 // NewFileFromFD creates a file object from the given file descriptor fd.
 func NewFileFromFD(fd uintptr) *File {
 	// TODO: Use fcntl or something to get the mode of the descriptor.
-	return &File{Object: Object{typ: FileType}, mode: "?", open: true, file: os.NewFile(fd, "<fdopen>")}
+	file := &File{Object: Object{typ: FileType}, mode: "?", open: true, file: os.NewFile(fd, "<fdopen>")}
+	file.reader = bufio.NewReader(file.file)
+	return file
 }
 
 func toFileUnsafe(o *Object) *File {