nmigen/tools.py

   1 from collections.abc import Iterable
   2 import functools
   3 import warnings
   4
   5
   6 __all__ = ["flatten", "union", "log2_int", "bits_for", "deprecated"]
   7
   8
   9 def flatten(i):
  10     for e in i:
  11         if isinstance(e, Iterable):
  12             yield from flatten(e)
  13         else:
  14             yield e
  15
  16
  17 def union(i, start=None):
  18     r = start
  19     for e in i:
  20         if r is None:
  21             r = e
  22         else:
  23             r |= e
  24     return r
  25
  26
  27 def log2_int(n, need_pow2=True):
  28     if n == 0:
  29         return 0
  30     r = (n - 1).bit_length()
  31     if need_pow2 and (1 << r) != n:
  32         raise ValueError("{} is not a power of 2".format(n))
  33     return r
  34
  35
  36 def bits_for(n, require_sign_bit=False):
  37     if n > 0:
  38         r = log2_int(n + 1, False)
  39     else:
  40         require_sign_bit = True
  41         r = log2_int(-n, False)
  42     if require_sign_bit:
  43         r += 1
  44     return r
  45
  46
  47 def deprecated(message, stacklevel=2):
  48     def decorator(f):
  49         @functools.wraps(f)
  50         def wrapper(*args, **kwargs):
  51             warnings.warn(message, DeprecationWarning, stacklevel=stacklevel)
  52             return f(*args, **kwargs)
  53         return wrapper
  54     return decorator
  55
  56
  57 def extend(cls):
  58     def decorator(f):
  59         if isinstance(f, property):
  60             name = f.fget.__name__
  61         else:
  62             name = f.__name__
  63         setattr(cls, name, f)
  64     return decorator