Esempio n. 1
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    def test_if_(self):
        """Test if_."""
        def return_nine():
            return 9

        def return_ten():
            return 10

        self.assertEqual(3, utils.if_(True, 3, 4))
        self.assertEqual(4, utils.if_(False, 3, 4))
        self.assertEqual(9, utils.if_(True, return_nine, return_ten))
        self.assertEqual(10, utils.if_(False, return_nine, return_ten))
Esempio n. 2
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  def test_if_(self):
    """Test if_."""
    def return_nine():
      return 9

    def return_ten():
      return 10

    self.assertEqual(3, utils.if_(True, 3, 4))
    self.assertEqual(4, utils.if_(False, 3, 4))
    self.assertEqual(9, utils.if_(True, return_nine, return_ten))
    self.assertEqual(10, utils.if_(False, return_nine, return_ten))
Esempio n. 3
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def unify(x, y, s):
    """Unify expressions x,y with substitution s; return a substitution that
  would make x,y equal, or None if x,y can not unify. x and y can be
  variables (e.g. Expr('x')), constants, lists, or Exprs. [Fig. 9.1]
  >>> unify(x + y, y + C, {})
  {y: C, x: y}
  """
    if s is None:
        return None
    elif x == y:
        return s
    elif is_variable(x):
        return unify_var(x, y, s)
    elif is_variable(y):
        return unify_var(y, x, s)
    elif isinstance(x, Expr) and isinstance(y, Expr):
        return unify(x.args, y.args, unify(x.op, y.op, s))
    elif isterm(x) or isterm(y) or not x or not y:
        return utils.if_(x == y, s, None)
    elif utils.is_sequence(x) and utils.is_sequence(y) and len(x) == len(y):
        return unify(x[1:], y[1:], unify(x[0], y[0], s))
    else:
        return None
Esempio n. 4
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def unify(x, y, s):
  """Unify expressions x,y with substitution s; return a substitution that
  would make x,y equal, or None if x,y can not unify. x and y can be
  variables (e.g. Expr('x')), constants, lists, or Exprs. [Fig. 9.1]
  >>> unify(x + y, y + C, {})
  {y: C, x: y}
  """
  if s is None:
    return None
  elif x == y:
    return s
  elif is_variable(x):
    return unify_var(x, y, s)
  elif is_variable(y):
    return unify_var(y, x, s)
  elif isinstance(x, Expr) and isinstance(y, Expr):
    return unify(x.args, y.args, unify(x.op, y.op, s))
  elif isterm(x) or isterm(y) or not x or not y:
    return utils.if_(x == y, s, None)
  elif utils.is_sequence(x) and utils.is_sequence(y) and len(x) == len(y):
    return unify(x[1:], y[1:], unify(x[0], y[0], s))
  else:
    return None