Merge pull request #72 from leonardt/rebind-bv

Rebind bv

hwtypes/adt_meta.py

@@ -12,13 +12,6 @@
 __all__ = ['BoundMeta', 'TupleMeta', 'ProductMeta', 'SumMeta', 'EnumMeta']
 
 
-def _issubclass(sub : tp.Any, parent : type) -> bool:
-    try:
-        return issubclass(sub, parent)
-    except TypeError:
-        return False
-
-
 def _is_dunder(name):
     return (len(name) > 4
             and name[:2] == name[-2:] == '__'
@@ -355,7 +348,11 @@ def rebind(cls, A : type, B : type):
                 new_fields[field] = T.rebind(A, B)
             else:
                 new_fields[field] = T
-        return cls.unbound_t.from_fields(cls.__name__, new_fields, cls.__module__, cls.__qualname__)
+
+        if new_fields != cls.field_dict:
+            return cls.unbound_t.from_fields(cls.__name__, new_fields, cls.__module__, cls.__qualname__)
+        else:
+            return cls
 
 class SumMeta(BoundMeta):
     def __new__(mcs, name, bases, namespace, fields=None, **kwargs):

hwtypes/adt_util.py

@@ -0,0 +1,19 @@
+from .adt_meta import BoundMeta
+from .bit_vector_abc import AbstractBitVectorMeta, AbstractBitVector
+
+from .util import _issubclass
+
+def rebind_bitvector(adt, bv_type: AbstractBitVectorMeta):
+    if _issubclass(adt, AbstractBitVector):
+        if adt.is_sized:
+            return bv_type[adt.size]
+        else:
+            return bv_type
+    elif isinstance(adt, BoundMeta):
+        new_adt = adt
+        for field in adt.fields:
+            new_field = rebind_bitvector(field, bv_type)
+            new_adt = new_adt.rebind(field, new_field)
+        return new_adt
+    else:
+        return adt

hwtypes/bit_vector_abc.py

@@ -5,6 +5,7 @@
 import weakref
 import warnings
 
+from .util import _issubclass
 
 TypeFamily = namedtuple('TypeFamily', ['Bit', 'BitVector', 'Unsigned', 'Signed'])
 

hwtypes/util.py

@@ -1,3 +1,5 @@
+import typing as tp
+
 class TypedProperty:
     '''
     Behaves mostly like property except:
@@ -82,3 +84,10 @@ def setter(self, fset):
 
     def deleter(self, fdel):
         return type(self)(self.T)(self.fget, self.fset, fdel, self.__doc__)
+
+
+def _issubclass(sub : tp.Any, parent : type) -> bool:
+    try:
+        return issubclass(sub, parent)
+    except TypeError:
+        return False

tests/test_adt.py

@@ -2,6 +2,8 @@
 from hwtypes.adt import Product, Sum, Enum, Tuple
 from hwtypes.adt_meta import _RESERVED_NAMES, ReservedNameError
 from hwtypes.modifiers import new
+from hwtypes.adt_util import rebind_bitvector
+from hwtypes.bit_vector import AbstractBitVector, BitVector
 
 class En1(Enum):
     a = 0
@@ -281,3 +283,29 @@ def test_rebind_recusrive():
     P4 = P3.rebind(C, D)
     assert P4.C == D
     assert D in P4.S1.fields
+    P5 = P2.rebind(P1, A)
+    assert P5.S1 == Sum[C, A]
+
+
+class F(Product):
+    Y = AbstractBitVector
+
+
+class P(Product):
+    X = AbstractBitVector[16]
+    S = Sum[AbstractBitVector[4], AbstractBitVector[8]]
+    T = Tuple[AbstractBitVector[32]]
+    F = F
+
+
+def test_rebind_bv():
+    P_bound = rebind_bitvector(P, BitVector)
+    assert P_bound.X == BitVector[16]
+    assert P_bound.S == Sum[BitVector[4], BitVector[8]]
+    assert P_bound.T[0] == BitVector[32]
+    assert P_bound.F.Y == BitVector
+
+    P_unbound = rebind_bitvector(P_bound, AbstractBitVector)
+    assert P_unbound.X == AbstractBitVector[16]
+    assert P_unbound.S == Sum[AbstractBitVector[4], AbstractBitVector[8]]
+    assert P_unbound.T[0] == AbstractBitVector[32]