Source Code for Module glitter.raw.constant

  1  """Named constants. 
  2  """ 
  3   
  4  import re 
  5  import types 
  6   
  7 -class NamedConstant(object): 
  8      """Named constant. 
  9      """ 
 10   
 11 -    def __init__(self, name): 
 12          self._name = name 
 13   
 14 -    def __repr__(self): 
 15          return "%s(%s)" % (self._name, super(NamedConstant, self).__repr__()) 
 16   
 17 -    def __str__(self): 
 18          return self._name 
 19   
 20 -class IntConstant(NamedConstant, int): 
 21      """Named integer constant. 
 22      """ 
 23   
 24 -    def __new__(cls, name, value): 
 25          return int.__new__(cls, value) 
 26   
 27 -    def __init__(self, name, value): 
 28          NamedConstant.__init__(self, name) 
 29   
 30 -    def __hash__(self): 
 31          return int.__hash__(self) 
 32   
 33 -    def _split_name(self): 
 34          i = 0 
 35          while i < len(self._name) and self._name[-i-1:].isdigit(): 
 36              i += 1 
 37          basename = self._name[:-i] 
 38          digit = int(self._name[-i:]) if i > 0 else None 
 39          return basename, digit 
 40   
 41 -    def __add__(self, other): 
 42          if isinstance(other, NamedConstant): 
 43              raise TypeError("cannot add two constants") 
 44          else: 
 45              basename, digit = self._split_name() 
 46              if digit is None: 
 47                  raise TypeError("not a numeric constant") 
 48              digit += other 
 49              if digit < 0: 
 50                  raise ValueError("range exceeded") 
 51              return type(self)("%s%d" % (basename, digit), super(NamedConstant, self).__add__(other)) 
 52   
 53 -    def __radd__(self, other): 
 54          return self.__add__(other) 
 55   
 56 -    def __sub__(self, other): 
 57          if isinstance(other, NamedConstant): 
 58              return super(NamedConstant, self).__sub__(other) 
 59          else: 
 60              basename, digit = self._split_name() 
 61              if digit is None: 
 62                  raise TypeError("not a numeric constant") 
 63              digit -= other 
 64              if digit < 0: 
 65                  raise ValueError("range exceeded") 
 66              return type(self)("%s%d" % (basename, digit), super(NamedConstant, self).__add__(other)) 
 67   
 68 -    def __or__(self, other): 
 69          return type(self)("%s|%s" % (self, other), super(NamedConstant, self).__or__(other)) 
 70   
 71 -    def __ror__(self, other): 
 72          return self | other 
 73   
 74 -def make_constant(name, value): 
 75      """Create a named constant with name C{name} and value C{value}. 
 76   
 77      An appropriate wrapper class will be generated if necessary. 
 78      """ 
 79   
 80      dtype = type(value) 
 81   
 82      cls_name = "%sConstant" % "".join(x[0].upper() + x[1:] for x in dtype.__name__.split()) 
 83      if cls_name not in globals(): 
 84          d = { 
 85              "__new__": lambda cls, name, value: dtype.__new__(cls, value), 
 86              "__init__": lambda self, name, value: NamedConstant.__init__(self, name), 
 87              "__hash__": lambda self: dtype.__hash__(self), 
 88          } 
 89          globals()[cls_name] = types.ClassType(cls_name, (NamedConstant, dtype), d) 
 90   
 91      return globals()[cls_name](name, value) 
 92   
 93 -def wrap_constants(name_re="^(GL|GLU|GLUT|GLX)_[A-Z][A-Z0-9_]*$", types=(int, long, float), d=None): 
 94      """Convert OpenGL constants to named constants. 
 95   
 96      All values in C{d} that match C{name_re} and are of one of the types in 
 97      C{types} will be replaced by corresponding L{NamedConstant}s. By default, 
 98      C{d} is C{glitter.raw.__dict__}. 
 99      """ 
100   
101      if d is None: 
102          from glitter import raw 
103          d = raw.__dict__ 
104   
105      for key, value in d.items(): 
106          if re.match(name_re, key) and isinstance(value, tuple(types)): 
107              d[key] = make_constant(key, value) 
108   
109  __all__ = ["NamedConstant", "wrap_constants"] 
110