Shadow.py

# cython.* namespace for pure mode.

compiled = False

def empty_decorator(x):
    return x

# Function decorators

def locals(**arg_types):
    return empty_decorator

def inline(f, *args, **kwds):
  if isinstance(f, basestring):
    from Cython.Build.Inline import cython_inline
    return cython_inline(f, *args, **kwds)
  else:
    assert len(args) == len(kwds) == 0
    return f

def compile(f):
    from Cython.Build.Inline import RuntimeCompiledFunction
    return RuntimeCompiledFunction(f)

# Special functions

def cdiv(a, b):
    q = a / b
    if q < 0:
        q += 1

def cmod(a, b):
    r = a % b
    if (a*b) < 0:
        r -= b
    return r


# Emulated language constructs

def cast(type, arg):
    if hasattr(type, '__call__'):
        return type(arg)
    else:
        return arg

def sizeof(arg):
    return 1

def typeof(arg):
    return type(arg)
    
def address(arg):
    return pointer(type(arg))([arg])
    
def declare(type=None, value=None, **kwds):
    if type is not None and hasattr(type, '__call__'):
        if value:
            return type(value)
        else:
            return type()
    else:
        return value

class _nogil(object):
    """Support for 'with nogil' statement
    """
    def __enter__(self):
        pass
    def __exit__(self, exc_class, exc, tb):
        return exc_class is None

nogil = _nogil()
del _nogil

# Emulated types

class CythonType(object):

    def _pointer(self, n=1):
        for i in range(n):
            self = pointer(self)
        return self

    def __getitem__(self, ix):
        return array(self, ix)


class PointerType(CythonType):

    def __init__(self, value=None):
        if isinstance(value, ArrayType):
            self._items = [cast(self._basetype, a) for a in value._items]
        elif isinstance(value, list):
            self._items = [cast(self._basetype, a) for a in value]
        elif value is None:
            self._items = []
        else:
            raise ValueError
            
    def __getitem__(self, ix):
        if ix < 0:
            raise IndexError("negative indexing not allowed in C")
        return self._items[ix]
        
    def __setitem__(self, ix, value):
        if ix < 0:
            raise IndexError("negative indexing not allowed in C")
        self._items[ix] = cast(self._basetype, value)
        
class ArrayType(PointerType):
    
    def __init__(self):
        self._items = [None] * self._n


class StructType(CythonType):
    
    def __init__(self, **data):
        for key, value in data.iteritems():
            setattr(self, key, value)
            
    def __setattr__(self, key, value):
        if key in self._members:
            self.__dict__[key] = cast(self._members[key], value)
        else:
            raise AttributeError("Struct has no member '%s'" % key)
    

class UnionType(CythonType):

    def __init__(self, **data):
        if len(data) > 0:
            raise AttributeError("Union can only store one field at a time.")
        for key, value in data.iteritems():
            setattr(self, key, value)
            
    def __setattr__(self, key, value):
        if key in '__dict__':
            CythonType.__setattr__(self, key, value)
        elif key in self._members:
            self.__dict__ = {key: cast(self._members[key], value)}
        else:
            raise AttributeError("Union has no member '%s'" % key)

def pointer(basetype):
    class PointerInstance(PointerType):
        _basetype = basetype
    return PointerInstance

def array(basetype, n):
    class ArrayInstance(ArrayType):
        _basetype = basetype
        _n = n
    return ArrayInstance

def struct(**members):
    class StructInstance(StructType):
        _members = members
    for key in members:
        setattr(StructInstance, key, None)
    return StructInstance

def union(**members):
    class UnionInstance(UnionType):
        _members = members
    for key in members:
        setattr(UnionInstance, key, None)
    return UnionInstance

class typedef(CythonType):

    def __init__(self, type):
        self._basetype = type
    
    def __call__(self, value=None):
        if value is not None:
            value = cast(self._basetype, value)
        return value
        


py_int = int
try:
    py_long = long
except NameError: # Py3
    py_long = int
py_float = float
py_complex = complex

try:
    # Python 3
    from builtins import set, frozenset
except ImportError:
    try:
        # Python 2.4+
        from __builtin__ import set, frozenset
    except ImportError:
        # Py 2.3
        from sets import Set as set, ImmutableSet as frozenset

# Predefined types

int_types = ['char', 'short', 'Py_UNICODE', 'int', 'long', 'longlong', 'Py_ssize_t', 'size_t']
float_types = ['longdouble', 'double', 'float']
complex_types = ['longdoublecomplex', 'doublecomplex', 'floatcomplex', 'complex']
other_types = ['bint', 'void']

gs = globals()

for name in int_types:
    gs[name] = typedef(py_int)
    if name != 'Py_UNICODE' and not name.endswith('size_t'):
        gs['u'+name] = typedef(py_int)
        gs['s'+name] = typedef(py_int)
    
for name in float_types:
    gs[name] = typedef(py_float)

for name in complex_types:
    gs[name] = typedef(py_complex)

bint = typedef(bool)
void = typedef(int)

for t in int_types + float_types + complex_types + other_types:
    for i in range(1, 4):
        gs["%s_%s" % ('p'*i, t)] = globals()[t]._pointer(i)

void = typedef(None)
NULL = None