migen.fhdl.structure: have Cat() flat_iteration-ize its arguments

diff --git a/migen/fhdl/structure.py b/migen/fhdl/structure.py
index a94c198b643a0abcaf1fbed754b83a62f601e1b8..aba747b308e3474dce9f99ebaf2fb50ab71b414d 100644 (file)
--- a/migen/fhdl/structure.py
+++ b/migen/fhdl/structure.py
@@ -4,6 +4,7 @@ import builtins
 from collections import defaultdict
 
 from migen.fhdl import tracer
+from migen.util.misc import flat_iteration
 
 class HUID:
        __next_uid = 0
@@ -87,7 +88,7 @@ class Value(HUID):
                elif isinstance(key, slice):
                        start, stop, step = key.indices(flen(self))
                        if step != 1:
-                               return Cat(*(self[i] for i in range(start, stop, step)))
+                               return Cat(self[i] for i in range(start, stop, step))
                        return _Slice(self, start, stop)
                else:
                        raise KeyError
@@ -155,11 +156,11 @@ class Cat(Value):
        meeting these properties. The bit length of the return value is the sum of
        the bit lengths of the arguments::
 
-               flen(Cat(*args)) == sum(flen(arg) for arg in args)
+               flen(Cat(args)) == sum(flen(arg) for arg in args)
 
        Parameters
        ----------
-       *args : Value, inout
+       *args : Values or iterables of Values, inout
                `Value` s to be concatenated.
 
        Returns
@@ -169,7 +170,7 @@ class Cat(Value):
        """
        def __init__(self, *args):
                Value.__init__(self)
-               self.l = args
+               self.l = list(flat_iteration(args))
 
 class Replicate(Value):
        """Replicate a value