New class. (MethodDefBase.__init__): Make 'self.ret' a 'ReturnType'

2008-07-14  Paul Pogonyshev  <pogonyshev@gmx.net>

	* codegen/definitions.py (ReturnType): New class.
	(MethodDefBase.__init__): Make 'self.ret' a 'ReturnType' instance,
	not string.  Accept 'optional' flag.

	* codegen/argtypes.py (ArgMatcher.get_reverse_ret): Test if
	'ptype' has true 'optional' attribute and copy it to 'props' then.

	* codegen/reversewrapper.py (ReturnType.support_optional): New
	class field, False by default.
	(GObjectReturn.support_optional, GObjectReturn.write_decl)
	(GObjectReturn.write_conversion): Support optional return.

svn path=/trunk/; revision=796

1 files changed, 17 insertions, 1 deletions

diff --git a/codegen/definitions.py b/codegen/definitions.py
index 617bcbe..5da488b 100644
--- a/codegen/definitions.py
+++ b/codegen/definitions.py
@@ -31,6 +31,17 @@ class Parameter(object):
         if old.pnull is not None:
             self.pnull = old.pnull
 
+# We currently subclass 'str' to make impact on the rest of codegen as
+# little as possible.  Later we can subclass 'object' instead, but
+# then we must find and adapt all places which expect return types to
+# be strings.
+class ReturnType(str):
+    def __new__(cls, *args, **kwds):
+        return str.__new__(cls, *args[:1])
+    def __init__(self, type_name, optional=False):
+        str.__init__(self, type_name)
+        self.optional = optional
+
 # Parameter for property based constructors
 class Property(object):
     def __init__(self, pname, optional, argname):
@@ -297,7 +308,12 @@ class MethodDefBase(Definition):
             elif arg[0] == 'gtype-id':
                 self.typecode = arg[1]
             elif arg[0] == 'return-type':
-                self.ret = arg[1]
+                type_name = arg[1]
+                optional = False
+                for prop in arg[2:]:
+                    if prop[0] == 'optional':
+                        optional = True
+                self.ret = ReturnType(type_name, optional)
             elif arg[0] == 'caller-owns-return':
                 self.caller_owns_return = arg[1] in ('t', '#t')
             elif arg[0] == 'unblock-threads':