Auto-convert character case for functions and allow private functions.

Private functions are available in the current script only: they use
Vim's <SID> prefix.

This fixes both issues #1 and #3.

examples/example6.vim

@@ -0,0 +1,26 @@
+python << eop
+import os
+import vim
+from vim_bridge import bridged
+
+@bridged
+def public():
+    return "I am public."
+
+@bridged
+def _private():
+    return "I am private (available in the current script only)."
+
+@bridged
+def my_name_is_auto_converted():
+    return "In Python, I'm called my_name_is_auto_converted, but in Vim, I'm called MyNameIsAutoConverted :)"
+
+@bridged
+def _long_private_name():
+    return "I'm private, and my case is converted automatically."
+eop
+
+echo Public()
+echo s:Private()
+echo MyNameIsAutoConverted()
+echo s:LongPrivateName()

vim_bridge/__init__.py

@@ -5,6 +5,13 @@
 VERSION = (0, 3)
 __version__ = ".".join(map(str, VERSION[0:2]))
 
+def _convert_function_name(fname):
+    private = fname.startswith('_')
+    if private:
+        fname = fname[1:]
+    fname = "".join([part.capitalize() for part in fname.split('_')])
+    return (private, fname)
+
 def _get_arguments(func):
     return func.func_code.co_varnames[:func.func_code.co_argcount]
 
@@ -14,7 +21,9 @@ def bridged(fin):
 
     func_args = _get_arguments(fin)
 
-    lines = ['fun! %s(%s)' % (fin.func_name, ", ".join(func_args))]
+    private, vimname = _convert_function_name(fin.func_name)
+    private = private and "s:" or ""
+    lines = ['fun! %s%s(%s)' % (private, vimname, ", ".join(func_args))]
     lines.append('python << endp')
     for arg in func_args:
         lines.append('__vim_bridge_%s = vim.eval("a:%s")' % (arg, arg))