Use a metaclass instead of @add_slots

10 files changed, 34 insertions, 33 deletions

diff --git a/attoconf/_version.py b/attoconf/_version.py
index 18e1fb6..791d3d9 100644
--- a/attoconf/_version.py
+++ b/attoconf/_version.py
@@ -11,7 +11,7 @@ minor = 9
 
 # Incremented if there is a bugfix release.
 # Might not be contiguous.
-patch = 0
+patch = 1
 
 # Reserved for distributors and forks.
 # Contains arbitrary text, but no parentheses or newlines.
diff --git a/attoconf/classy.py b/attoconf/classy.py
index a27230d..98d54aa 100644
--- a/attoconf/classy.py
+++ b/attoconf/classy.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
@@ -19,24 +19,33 @@ from __future__ import print_function, division, absolute_import
 
 from .core import Project, Build
 
-# TODO: put this in a metaclass
-# some of the init/jiggle logic would also be simplified by a metaclass
+class PolymorphicSlotMergerMetaclass(type):
+
+    def __new__(meta, name, bases, dct):
+        if '__slots__' not in dct:
+            s = ()
+            for b in bases:
+                s2 = b.__dict__.get('_merge_slots_', ())
+                if isinstance(s2, basestring):
+                    s2 = (s2,)
+                s += s2
+            s += dct.get('_merge_slots_', ())
+            dct['__slots__'] = s
+        else:
+            assert dct['__slots__'] == ()
+        return type.__new__(meta, name, bases, dct)
+
+
+# TODO: remove this for 1.0
 def add_slots(cls):
-    ''' A decorator that fixes __slots__ after multiple inheritance.
-    '''
-    return type(cls.__name__, cls.__bases__,
-            dict(cls.__dict__, __slots__=cls.slots()))
+    return cls
 
 class ClassyProject(Project):
     ''' A more convenient, objectish, way of setting up a project.
     '''
     __slots__ = ()
-    @classmethod
-    def slots(self):
-        ''' slots don't work too well with multiple inheritance,
-            so make the most-derived class create all the slots
-        '''
-        return ()
+    _merge_slots_ = ()
+    __metaclass__ = PolymorphicSlotMergerMetaclass
 
     def __init__(self, srcdir):
         super(ClassyProject, self).__init__(srcdir)
diff --git a/attoconf/core.py b/attoconf/core.py
index 0d196e9..8fff40f 100644
--- a/attoconf/core.py
+++ b/attoconf/core.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
diff --git a/attoconf/lib/arches.py b/attoconf/lib/arches.py
index 8c70f0b..63f6244 100644
--- a/attoconf/lib/arches.py
+++ b/attoconf/lib/arches.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
diff --git a/attoconf/lib/c.py b/attoconf/lib/c.py
index bc32c49..03f77da 100644
--- a/attoconf/lib/c.py
+++ b/attoconf/lib/c.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
diff --git a/attoconf/lib/install.py b/attoconf/lib/install.py
index f43b2a1..3dc7f5b 100644
--- a/attoconf/lib/install.py
+++ b/attoconf/lib/install.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
@@ -141,11 +141,7 @@ def psdir(build, DIR):
 
 class Install(ClassyProject):
     __slots__ = ()
-
-    @classmethod
-    def slots(cls):
-        return super(Install, cls).slots() + (
-                'package', 'package_name')
+    _merge_slots_ = ('package', 'package_name')
 
     # Compatibility with configure written for attoconf < 0.7
     # In attoconf 1.0, the positional srcdir argument will go away,
diff --git a/attoconf/lib/make.py b/attoconf/lib/make.py
index b965f28..f815cd0 100644
--- a/attoconf/lib/make.py
+++ b/attoconf/lib/make.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
@@ -62,9 +62,7 @@ class Make(ClassyProject):
     ''' Post hook to generate a Makefile from Makefile.in
     '''
     __slots__ = ()
-    @classmethod
-    def slots(cls):
-        return super(Make, cls).slots() + ('make_in', 'make_out')
+    _merge_slots_ = ('make_in', 'make_out')
 
     # compatibility with attoconf < 0.7
     def __init__(self, srcdir,
diff --git a/attoconf/lib/templates.py b/attoconf/lib/templates.py
index d6fc24d..0ec1a3e 100644
--- a/attoconf/lib/templates.py
+++ b/attoconf/lib/templates.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
@@ -62,9 +62,7 @@ class Templates(ClassyProject):
     ''' Post hook to generate output files from *.in templates
     '''
     __slots__ = ()
-    @classmethod
-    def slots(cls):
-        return super(Templates, cls).slots() + ('template_files',)
+    _merge_slots_ = ('template_files')
 
     # this class didn't exist in attoconf < 0.7, no need for compatibility
     def __init__(self, template_files, **kwargs):
diff --git a/attoconf/tests/test_core.py b/attoconf/tests/test_core.py
index 09c2c64..d8de71f 100644
--- a/attoconf/tests/test_core.py
+++ b/attoconf/tests/test_core.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #
diff --git a/attoconf/types.py b/attoconf/types.py
index e7c8465..8a8d56a 100644
--- a/attoconf/types.py
+++ b/attoconf/types.py
@@ -1,4 +1,4 @@
-#   Copyright 2013 Ben Longbons <b.r.longbons@gmail.com>
+#   Copyright 2013-2014 Ben Longbons <b.r.longbons@gmail.com>
 #
 #   This file is part of attoconf.
 #