sympy/core/methods.py

   1 """ Defines default methods for unary and binary operations.
   2 """
   3
   4 from basic import Basic, S, SympifyError, sympify
   5 #from add import Add    /cyclic/
   6 #from mul import Mul    /cyclic/
   7 #from pow import Pow    /cyclic/
   8 #from relational import Equality, Unequality, Inequality, StrictInequality /cyclic/
   9 #from sympy.functions.elementary.complexes import abs as abs_   /cyclic/
  10
  11 def _no_unary_operation(op, obj):
  12     return 'unary operation `%s` not defined for %s' % (op, obj.__class__.__name__)
  13 def _no_binary_operation(op, obj1, obj2):
  14     return 'binary operation `%s` not defined between %s and %s' \
  15            % (op, obj1.__class__.__name__, obj2.__class__.__name__)
  16
  17 class ArithMeths(object):
  18
  19     def __pos__(self):
  20         return self
  21     def __neg__(self):
  22         return S.NegativeOne * self
  23     def __abs__(self):
  24         return abs_(self)
  25     def __add__(self, other):
  26         try:
  27             other = sympify(other)
  28         except SympifyError:
  29             return NotImplemented
  30         if not isinstance(other, Basic):
  31             return NotImplemented
  32         return Add(self, other)
  33     def __radd__(self, other):
  34         return sympify(other).__add__(self)
  35     def __sub__(self, other):
  36         try:
  37             other = sympify(other)
  38         except SympifyError:
  39             return NotImplemented
  40         if not isinstance(other, Basic):
  41             return NotImplemented
  42         return self + (-other)
  43     def __rsub__(self, other):
  44         return sympify(other).__sub__(self)
  45     def __mul__(self, other):
  46         # FIXME this is a dirty hack. matrix should be ordinary SymPy object
  47         from sympy.matrices import Matrix
  48         if isinstance(other, Matrix): return NotImplemented
  49         try:
  50             other = sympify(other)
  51         except SympifyError:
  52             return NotImplemented
  53         if not isinstance(other, Basic):
  54             return NotImplemented
  55         return Mul(self, other)
  56     def __rmul__(self, other):
  57         return sympify(other).__mul__(self)
  58     def __pow__(self, other):
  59         try:
  60             other = sympify(other)
  61         except SympifyError:
  62             return NotImplemented
  63         if not isinstance(other, Basic):
  64             return NotImplemented
  65         return Pow(self, other)
  66     def __rpow__(self, other):
  67         try:
  68             other = sympify(other)
  69         except SympifyError:
  70             return NotImplemented
  71         if not isinstance(other, Basic):
  72             return NotImplemented
  73         return other.__pow__(self)
  74     def __div__(self, other):
  75         try:
  76             other = sympify(other)
  77         except SympifyError:
  78             return NotImplemented
  79         if not isinstance(other, Basic):
  80             return NotImplemented
  81         return self * (other ** S.NegativeOne)
  82     def __truediv__(self, other):
  83         return self.__div__(other)
  84     def __rdiv__(self, other):
  85         return sympify(other).__div__(self)
  86     def __rtruediv__(self, other):
  87         return self.__rdiv__(other)
  88
  89 class NoArithMeths(object):
  90
  91     def __pos__(self):
  92         raise TypeError, _no_unary_operation('+', self)
  93     def __neg__(self):
  94         raise TypeError, _no_unary_operation('-', self)
  95     def __add__(self, other):
  96         raise TypeError, _no_binary_operation('+', self, other)
  97     def __radd__(self, other):
  98         raise TypeError, _no_binary_operation('+', other, self)
  99     def __sub__(self, other):
 100         raise TypeError, _no_binary_operation('-', self, other)
 101     def __rsub__(self, other):
 102         raise TypeError, _no_binary_operation('-', other, self)
 103     def __mul__(self, other):
 104         raise TypeError, _no_binary_operation('*', self, other)
 105     def __rmul__(self, other):
 106         raise TypeError, _no_binary_operation('*', other, self)
 107     def __div__(self, other):
 108         raise TypeError, _no_binary_operation('/', self, other)
 109     def __rdiv__(self, other):
 110         raise TypeError, _no_binary_operation('/', other, self)
 111     def __pow__(self, other):
 112         raise TypeError, _no_binary_operation('**', self, other)
 113     def __rpow__(self, other):
 114         raise TypeError, _no_binary_operation('**', other, self)
 115     def _eval_power(self, other):
 116         return None
 117
 118 class RelMeths(object):
 119
 120     def __eq__(self, other):
 121         try:
 122             other = sympify(other)
 123         except ValueError:
 124             return False
 125         return Equality(self, other)
 126     def __ne__(self, other):
 127         try:
 128             other = sympify(other)
 129         except ValueError:
 130             return True
 131         return Unequality(self, other)
 132     def __lt__(self, other):
 133         #return sympify(other) > self
 134         return StrictInequality(self, other)
 135     def __gt__(self, other):
 136         return StrictInequality(other, self)
 137         #return sympify(other) < self
 138     def __le__(self, other):
 139         return Inequality(self, other)
 140     def __ge__(self, other):
 141         return sympify(other) <= self
 142
 143 class NoRelMeths(object):
 144
 145     def __eq__(self, other):
 146         return Equality(self, other)
 147     def __ne__(self, other):
 148         return Unequality(self, other)
 149     def __lt__(self, other):
 150         return hash(self) < hash(other)
 151         raise TypeError, _no_binary_operation('<', self, other)
 152     def __gt__(self, other):
 153         return hash(self) > hash(other)
 154         raise TypeError, _no_binary_operation('>', self, other)
 155     def __le__(self, other):
 156         raise TypeError, _no_binary_operation('<=', self, other)
 157     def __ge__(self, other):
 158         raise TypeError, _no_binary_operation('>=', self, other)