ceph/src/boost/tools/build/src/util/set.py

   1 #  (C) Copyright David Abrahams 2001. Permission to copy, use, modify, sell and
   2 #  distribute this software is granted provided this copyright notice appears in
   3 #  all copies. This software is provided "as is" without express or implied
   4 #  warranty, and with no claim as to its suitability for any purpose.
   5
   6 from b2.util import is_iterable
   7 from .utility import to_seq
   8
   9
  10 def difference (b, a):
  11     """ Returns the elements of B that are not in A.
  12     """
  13     a = set(a)
  14     result = []
  15     for item in b:
  16         if item not in a:
  17             result.append(item)
  18     return result
  19
  20 def intersection (set1, set2):
  21     """ Removes from set1 any items which don't appear in set2 and returns the result.
  22     """
  23     assert is_iterable(set1)
  24     assert is_iterable(set2)
  25     result = []
  26     for v in set1:
  27         if v in set2:
  28             result.append (v)
  29     return result
  30
  31 def contains (small, large):
  32     """ Returns true iff all elements of 'small' exist in 'large'.
  33     """
  34     small = to_seq (small)
  35     large = to_seq (large)
  36
  37     for s in small:
  38         if not s in large:
  39             return False
  40     return True
  41
  42 def equal (a, b):
  43     """ Returns True iff 'a' contains the same elements as 'b', irrespective of their order.
  44         # TODO: Python 2.4 has a proper set class.
  45     """
  46     assert is_iterable(a)
  47     assert is_iterable(b)
  48     return contains (a, b) and contains (b, a)