Modules/operator.c

#include "Python.h"

PyDoc_STRVAR(operator_doc,
"Operator interface.\n\
\n\
This module exports a set of functions implemented in C corresponding\n\
to the intrinsic operators of Python.  For example, operator.add(x, y)\n\
is equivalent to the expression x+y.  The function names are those\n\
used for special class methods; variants without leading and trailing\n\
'__' are also provided for convenience.");

#define spam1(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a1) { \
  return AOP(a1); }

#define spam2(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2; \
  if(! PyArg_UnpackTuple(a,#OP,2,2,&a1,&a2)) return NULL; \
  return AOP(a1,a2); }

#define spamoi(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1; int a2; \
  if(! PyArg_ParseTuple(a,"Oi:" #OP,&a1,&a2)) return NULL; \
  return AOP(a1,a2); }

#define spam2n(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2; \
  if(! PyArg_UnpackTuple(a,#OP,2,2,&a1,&a2)) return NULL; \
  if(-1 == AOP(a1,a2)) return NULL; \
  Py_INCREF(Py_None); \
  return Py_None; }

#define spam3n(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2, *a3; \
  if(! PyArg_UnpackTuple(a,#OP,3,3,&a1,&a2,&a3)) return NULL; \
  if(-1 == AOP(a1,a2,a3)) return NULL; \
  Py_INCREF(Py_None); \
  return Py_None; }

#define spami(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a1) { \
  long r; \
  if(-1 == (r=AOP(a1))) return NULL; \
  return PyBool_FromLong(r); }

#define spami2(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2; long r; \
  if(! PyArg_UnpackTuple(a,#OP,2,2,&a1,&a2)) return NULL; \
  if(-1 == (r=AOP(a1,a2))) return NULL; \
  return PyInt_FromLong(r); }

#define spamn2(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2; Py_ssize_t r; \
  if(! PyArg_UnpackTuple(a,#OP,2,2,&a1,&a2)) return NULL; \
  if(-1 == (r=AOP(a1,a2))) return NULL; \
  return PyInt_FromSsize_t(r); }

#define spami2b(OP,AOP) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2; long r; \
  if(! PyArg_UnpackTuple(a,#OP,2,2,&a1,&a2)) return NULL; \
  if(-1 == (r=AOP(a1,a2))) return NULL; \
  return PyBool_FromLong(r); }

#define spamrc(OP,A) static PyObject *OP(PyObject *s, PyObject *a) { \
  PyObject *a1, *a2; \
  if(! PyArg_UnpackTuple(a,#OP,2,2,&a1,&a2)) return NULL; \
  return PyObject_RichCompare(a1,a2,A); }

spami(isCallable       , PyCallable_Check)
spami(isNumberType     , PyNumber_Check)
spami(truth            , PyObject_IsTrue)
spam2(op_add           , PyNumber_Add)
spam2(op_sub           , PyNumber_Subtract)
spam2(op_mul           , PyNumber_Multiply)
spam2(op_div           , PyNumber_Divide)
spam2(op_floordiv      , PyNumber_FloorDivide)
spam2(op_truediv       , PyNumber_TrueDivide)
spam2(op_mod           , PyNumber_Remainder)
spam1(op_neg           , PyNumber_Negative)
spam1(op_pos           , PyNumber_Positive)
spam1(op_abs           , PyNumber_Absolute)
spam1(op_inv           , PyNumber_Invert)
spam1(op_invert        , PyNumber_Invert)
spam2(op_lshift        , PyNumber_Lshift)
spam2(op_rshift        , PyNumber_Rshift)
spami(op_not_          , PyObject_Not)
spam2(op_and_          , PyNumber_And)
spam2(op_xor           , PyNumber_Xor)
spam2(op_or_           , PyNumber_Or)
spam2(op_iadd          , PyNumber_InPlaceAdd)
spam2(op_isub          , PyNumber_InPlaceSubtract)
spam2(op_imul          , PyNumber_InPlaceMultiply)
spam2(op_idiv          , PyNumber_InPlaceDivide)
spam2(op_ifloordiv     , PyNumber_InPlaceFloorDivide)
spam2(op_itruediv      , PyNumber_InPlaceTrueDivide)
spam2(op_imod          , PyNumber_InPlaceRemainder)
spam2(op_ilshift       , PyNumber_InPlaceLshift)
spam2(op_irshift       , PyNumber_InPlaceRshift)
spam2(op_iand          , PyNumber_InPlaceAnd)
spam2(op_ixor          , PyNumber_InPlaceXor)
spam2(op_ior           , PyNumber_InPlaceOr)
spami(isSequenceType   , PySequence_Check)
spam2(op_concat        , PySequence_Concat)
spamoi(op_repeat       , PySequence_Repeat)
spam2(op_iconcat       , PySequence_InPlaceConcat)
spamoi(op_irepeat      , PySequence_InPlaceRepeat)
spami2b(op_contains     , PySequence_Contains)
spami2b(sequenceIncludes, PySequence_Contains)
spamn2(indexOf         , PySequence_Index)
spamn2(countOf         , PySequence_Count)
spami(isMappingType    , PyMapping_Check)
spam2(op_getitem       , PyObject_GetItem)
spam2n(op_delitem       , PyObject_DelItem)
spam3n(op_setitem      , PyObject_SetItem)
spamrc(op_lt           , Py_LT)
spamrc(op_le           , Py_LE)
spamrc(op_eq           , Py_EQ)
spamrc(op_ne           , Py_NE)
spamrc(op_gt           , Py_GT)
spamrc(op_ge           , Py_GE)

static PyObject*
op_pow(PyObject *s, PyObject *a)
{
	PyObject *a1, *a2;
	if (PyArg_UnpackTuple(a,"pow", 2, 2, &a1, &a2))
		return PyNumber_Power(a1, a2, Py_None);
	return NULL;
}

static PyObject*
op_ipow(PyObject *s, PyObject *a)
{
	PyObject *a1, *a2;
	if (PyArg_UnpackTuple(a,"ipow", 2, 2, &a1, &a2))
		return PyNumber_InPlacePower(a1, a2, Py_None);
	return NULL;
}

static PyObject *
op_index(PyObject *s, PyObject *a)
{
	return PyNumber_Index(a);
}

static PyObject*
is_(PyObject *s, PyObject *a)
{
	PyObject *a1, *a2, *result = NULL;
	if (PyArg_UnpackTuple(a,"is_", 2, 2, &a1, &a2)) {
		result = (a1 == a2) ? Py_True : Py_False;
		Py_INCREF(result);
	}
	return result;
}

static PyObject*
is_not(PyObject *s, PyObject *a)
{
	PyObject *a1, *a2, *result = NULL;
	if (PyArg_UnpackTuple(a,"is_not", 2, 2, &a1, &a2)) {
		result = (a1 != a2) ? Py_True : Py_False;
		Py_INCREF(result);
	}
	return result;
}

static PyObject*
op_getslice(PyObject *s, PyObject *a)
{
        PyObject *a1;
        Py_ssize_t a2, a3;

        if (!PyArg_ParseTuple(a, "Onn:getslice", &a1, &a2, &a3))
                return NULL;
        return PySequence_GetSlice(a1, a2, a3);
}

static PyObject*
op_setslice(PyObject *s, PyObject *a)
{
        PyObject *a1, *a4;
        Py_ssize_t a2, a3;

        if (!PyArg_ParseTuple(a, "OnnO:setslice", &a1, &a2, &a3, &a4))
                return NULL;

        if (-1 == PySequence_SetSlice(a1, a2, a3, a4))
                return NULL;

	Py_RETURN_NONE;
}

static PyObject*
op_delslice(PyObject *s, PyObject *a)
{
        PyObject *a1;
        Py_ssize_t a2, a3;

        if (!PyArg_ParseTuple(a, "Onn:delslice", &a1, &a2, &a3))
                return NULL;

        if (-1 == PySequence_DelSlice(a1, a2, a3))
                return NULL;

	Py_RETURN_NONE;
}

#undef spam1
#undef spam2
#undef spam1o
#undef spam1o
#define spam1(OP,DOC) {#OP, OP, METH_VARARGS, PyDoc_STR(DOC)},
#define spam2(OP,ALTOP,DOC) {#OP, op_##OP, METH_VARARGS, PyDoc_STR(DOC)}, \
			   {#ALTOP, op_##OP, METH_VARARGS, PyDoc_STR(DOC)}, 
#define spam1o(OP,DOC) {#OP, OP, METH_O, PyDoc_STR(DOC)},
#define spam2o(OP,ALTOP,DOC) {#OP, op_##OP, METH_O, PyDoc_STR(DOC)}, \
			   {#ALTOP, op_##OP, METH_O, PyDoc_STR(DOC)}, 

static struct PyMethodDef operator_methods[] = {

spam1o(isCallable,
 "isCallable(a) -- Same as callable(a).")
spam1o(isNumberType,
 "isNumberType(a) -- Return True if a has a numeric type, False otherwise.")
spam1o(isSequenceType,
 "isSequenceType(a) -- Return True if a has a sequence type, False otherwise.")
spam1o(truth,
 "truth(a) -- Return True if a is true, False otherwise.")
spam2(contains,__contains__,
 "contains(a, b) -- Same as b in a (note reversed operands).")
spam1(sequenceIncludes,
 "sequenceIncludes(a, b) -- Same as b in a (note reversed operands; deprecated).")
spam1(indexOf,
 "indexOf(a, b) -- Return the first index of b in a.")
spam1(countOf,
 "countOf(a, b) -- Return the number of times b occurs in a.")
spam1o(isMappingType,
 "isMappingType(a) -- Return True if a has a mapping type, False otherwise.")

spam1(is_, "is_(a, b) -- Same as a is b.")
spam1(is_not, "is_not(a, b) -- Same as a is not b.")
spam2o(index, __index__, "index(a) -- Same as a.__index__()")
spam2(add,__add__, "add(a, b) -- Same as a + b.")
spam2(sub,__sub__, "sub(a, b) -- Same as a - b.")
spam2(mul,__mul__, "mul(a, b) -- Same as a * b.")
spam2(div,__div__, "div(a, b) -- Same as a / b when __future__.division is not in effect.")
spam2(floordiv,__floordiv__, "floordiv(a, b) -- Same as a // b.")
spam2(truediv,__truediv__, "truediv(a, b) -- Same as a / b when __future__.division is in effect.")
spam2(mod,__mod__, "mod(a, b) -- Same as a % b.")
spam2o(neg,__neg__, "neg(a) -- Same as -a.")
spam2o(pos,__pos__, "pos(a) -- Same as +a.")
spam2o(abs,__abs__, "abs(a) -- Same as abs(a).")
spam2o(inv,__inv__, "inv(a) -- Same as ~a.")
spam2o(invert,__invert__, "invert(a) -- Same as ~a.")
spam2(lshift,__lshift__, "lshift(a, b) -- Same as a << b.")
spam2(rshift,__rshift__, "rshift(a, b) -- Same as a >> b.")
spam2o(not_,__not__, "not_(a) -- Same as not a.")
spam2(and_,__and__, "and_(a, b) -- Same as a & b.")
spam2(xor,__xor__, "xor(a, b) -- Same as a ^ b.")
spam2(or_,__or__, "or_(a, b) -- Same as a | b.")
spam2(iadd,__iadd__, "iadd(a, b) -- Same as a += b.")
spam2(isub,__isub__, "isub(a, b) -- Same as a -= b.")
spam2(imul,__imul__, "imul(a, b) -- Same as a *= b.")
spam2(idiv,__idiv__, "idiv(a, b) -- Same as a /= b when __future__.division is not in effect.")
spam2(ifloordiv,__ifloordiv__, "ifloordiv(a, b) -- Same as a //= b.")
spam2(itruediv,__itruediv__, "itruediv(a, b) -- Same as a /= b when __future__.division is in effect.")
spam2(imod,__imod__, "imod(a, b) -- Same as a %= b.")
spam2(ilshift,__ilshift__, "ilshift(a, b) -- Same as a <<= b.")
spam2(irshift,__irshift__, "irshift(a, b) -- Same as a >>= b.")
spam2(iand,__iand__, "iand(a, b) -- Same as a &= b.")
spam2(ixor,__ixor__, "ixor(a, b) -- Same as a ^= b.")
spam2(ior,__ior__, "ior(a, b) -- Same as a |= b.")
spam2(concat,__concat__,
 "concat(a, b) -- Same as a + b, for a and b sequences.")
spam2(repeat,__repeat__,
 "repeat(a, b) -- Return a * b, where a is a sequence, and b is an integer.")
spam2(iconcat,__iconcat__,
 "iconcat(a, b) -- Same as a += b, for a and b sequences.")
spam2(irepeat,__irepeat__,
 "irepeat(a, b) -- Same as a *= b, where a is a sequence, and b is an integer.")
spam2(getitem,__getitem__,
 "getitem(a, b) -- Same as a[b].")
spam2(setitem,__setitem__,
 "setitem(a, b, c) -- Same as a[b] = c.")
spam2(delitem,__delitem__,
 "delitem(a, b) -- Same as del a[b].")
spam2(pow,__pow__, "pow(a, b) -- Same as a ** b.")
spam2(ipow,__ipow__, "ipow(a, b) -- Same as a **= b.")
spam2(getslice,__getslice__,
 "getslice(a, b, c) -- Same as a[b:c].")
spam2(setslice,__setslice__,
"setslice(a, b, c, d) -- Same as a[b:c] = d.")
spam2(delslice,__delslice__,
"delslice(a, b, c) -- Same as del a[b:c].")
spam2(lt,__lt__, "lt(a, b) -- Same as a<b.")
spam2(le,__le__, "le(a, b) -- Same as a<=b.")
spam2(eq,__eq__, "eq(a, b) -- Same as a==b.")
spam2(ne,__ne__, "ne(a, b) -- Same as a!=b.")
spam2(gt,__gt__, "gt(a, b) -- Same as a>b.")
spam2(ge,__ge__, "ge(a, b) -- Same as a>=b.")

	{NULL,		NULL}		/* sentinel */

};

/* itemgetter object **********************************************************/

typedef struct {
	PyObject_HEAD
	Py_ssize_t nitems;
	PyObject *item;
} itemgetterobject;

static PyTypeObject itemgetter_type;

static PyObject *
itemgetter_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	itemgetterobject *ig;
	PyObject *item;
	Py_ssize_t nitems;

	if (!_PyArg_NoKeywords("itemgetter()", kwds))
		return NULL;

	nitems = PyTuple_GET_SIZE(args);
	if (nitems <= 1) {
		if (!PyArg_UnpackTuple(args, "itemgetter", 1, 1, &item))
			return NULL;
	} else 
		item = args;

	/* create itemgetterobject structure */
	ig = PyObject_GC_New(itemgetterobject, &itemgetter_type);
	if (ig == NULL) 
		return NULL;	
	
	Py_INCREF(item);
	ig->item = item;
	ig->nitems = nitems;

	PyObject_GC_Track(ig);
	return (PyObject *)ig;
}

static void
itemgetter_dealloc(itemgetterobject *ig)
{
	PyObject_GC_UnTrack(ig);
	Py_XDECREF(ig->item);
	PyObject_GC_Del(ig);
}

static int
itemgetter_traverse(itemgetterobject *ig, visitproc visit, void *arg)
{
	Py_VISIT(ig->item);
	return 0;
}

static PyObject *
itemgetter_call(itemgetterobject *ig, PyObject *args, PyObject *kw)
{
	PyObject *obj, *result;
	Py_ssize_t i, nitems=ig->nitems;

	if (!PyArg_UnpackTuple(args, "itemgetter", 1, 1, &obj))
		return NULL;
	if (nitems == 1)
		return PyObject_GetItem(obj, ig->item);

	assert(PyTuple_Check(ig->item));
	assert(PyTuple_GET_SIZE(ig->item) == nitems);

	result = PyTuple_New(nitems);
	if (result == NULL)
		return NULL;

	for (i=0 ; i < nitems ; i++) {
		PyObject *item, *val;
		item = PyTuple_GET_ITEM(ig->item, i);
		val = PyObject_GetItem(obj, item);
		if (val == NULL) {
			Py_DECREF(result);
			return NULL;
		}
		PyTuple_SET_ITEM(result, i, val);
	}
	return result;
}

PyDoc_STRVAR(itemgetter_doc,
"itemgetter(item, ...) --> itemgetter object\n\
\n\
Return a callable object that fetches the given item(s) from its operand.\n\
After, f=itemgetter(2), the call f(r) returns r[2].\n\
After, g=itemgetter(2,5,3), the call g(r) returns (r[2], r[5], r[3])");

static PyTypeObject itemgetter_type = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"operator.itemgetter",		/* tp_name */
	sizeof(itemgetterobject),	/* tp_basicsize */
	0,				/* tp_itemsize */
	/* methods */
	(destructor)itemgetter_dealloc,	/* tp_dealloc */
	0,				/* tp_print */
	0,				/* tp_getattr */
	0,				/* tp_setattr */
	0,				/* tp_compare */
	0,				/* tp_repr */
	0,				/* tp_as_number */
	0,				/* tp_as_sequence */
	0,				/* tp_as_mapping */
	0,				/* tp_hash */
	(ternaryfunc)itemgetter_call,	/* tp_call */
	0,				/* tp_str */
	PyObject_GenericGetAttr,	/* tp_getattro */
	0,				/* tp_setattro */
	0,				/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,	/* tp_flags */
	itemgetter_doc,			/* tp_doc */
	(traverseproc)itemgetter_traverse,	/* tp_traverse */
	0,				/* tp_clear */
	0,				/* tp_richcompare */
	0,				/* tp_weaklistoffset */
	0,				/* tp_iter */
	0,				/* tp_iternext */
	0,				/* tp_methods */
	0,				/* tp_members */
	0,				/* tp_getset */
	0,				/* tp_base */
	0,				/* tp_dict */
	0,				/* tp_descr_get */
	0,				/* tp_descr_set */
	0,				/* tp_dictoffset */
	0,				/* tp_init */
	0,				/* tp_alloc */
	itemgetter_new,			/* tp_new */
	0,				/* tp_free */
};


/* attrgetter object **********************************************************/

typedef struct {
	PyObject_HEAD
	Py_ssize_t nattrs;
	PyObject *attr;
} attrgetterobject;

static PyTypeObject attrgetter_type;

static PyObject *
attrgetter_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	attrgetterobject *ag;
	PyObject *attr;
	Py_ssize_t nattrs;

	if (!_PyArg_NoKeywords("attrgetter()", kwds))
		return NULL;

	nattrs = PyTuple_GET_SIZE(args);
	if (nattrs <= 1) {
		if (!PyArg_UnpackTuple(args, "attrgetter", 1, 1, &attr))
			return NULL;
	} else 
		attr = args;

	/* create attrgetterobject structure */
	ag = PyObject_GC_New(attrgetterobject, &attrgetter_type);
	if (ag == NULL) 
		return NULL;	
	
	Py_INCREF(attr);
	ag->attr = attr;
	ag->nattrs = nattrs;

	PyObject_GC_Track(ag);
	return (PyObject *)ag;
}

static void
attrgetter_dealloc(attrgetterobject *ag)
{
	PyObject_GC_UnTrack(ag);
	Py_XDECREF(ag->attr);
	PyObject_GC_Del(ag);
}

static int
attrgetter_traverse(attrgetterobject *ag, visitproc visit, void *arg)
{
	Py_VISIT(ag->attr);
	return 0;
}

static PyObject *
dotted_getattr(PyObject *obj, PyObject *attr)
{
	char *s, *p;

#ifdef Py_USING_UNICODE
	if (PyUnicode_Check(attr)) {
		attr = _PyUnicode_AsDefaultEncodedString(attr, NULL);
		if (attr == NULL)
			return NULL;
	}
#endif
	
	if (!PyString_Check(attr)) {
		PyErr_SetString(PyExc_TypeError,
				"attribute name must be a string");
		return NULL;
	}

	s = PyString_AS_STRING(attr);
	Py_INCREF(obj);
	for (;;) {
		PyObject *newobj, *str;
		p = strchr(s, '.');
		str = p ? PyString_FromStringAndSize(s, (p-s)) : 
			  PyString_FromString(s);
		if (str == NULL) {
			Py_DECREF(obj);
			return NULL;
		}
		newobj = PyObject_GetAttr(obj, str);
		Py_DECREF(str);
		Py_DECREF(obj);
		if (newobj == NULL)
			return NULL;
		obj = newobj;
		if (p == NULL) break;
		s = p+1;
	}

	return obj;
}

static PyObject *
attrgetter_call(attrgetterobject *ag, PyObject *args, PyObject *kw)
{
	PyObject *obj, *result;
	Py_ssize_t i, nattrs=ag->nattrs;

	if (!PyArg_UnpackTuple(args, "attrgetter", 1, 1, &obj))
		return NULL;
	if (ag->nattrs == 1)
		return dotted_getattr(obj, ag->attr);

	assert(PyTuple_Check(ag->attr));
	assert(PyTuple_GET_SIZE(ag->attr) == nattrs);

	result = PyTuple_New(nattrs);
	if (result == NULL)
		return NULL;

	for (i=0 ; i < nattrs ; i++) {
		PyObject *attr, *val;
		attr = PyTuple_GET_ITEM(ag->attr, i);
		val = dotted_getattr(obj, attr);
		if (val == NULL) {
			Py_DECREF(result);
			return NULL;
		}
		PyTuple_SET_ITEM(result, i, val);
	}
	return result;
}

PyDoc_STRVAR(attrgetter_doc,
"attrgetter(attr, ...) --> attrgetter object\n\
\n\
Return a callable object that fetches the given attribute(s) from its operand.\n\
After, f=attrgetter('name'), the call f(r) returns r.name.\n\
After, g=attrgetter('name', 'date'), the call g(r) returns (r.name, r.date).\n\
After, h=attrgetter('name.first', 'name.last'), the call h(r) returns\n\
(r.name.first, r.name.last).");

static PyTypeObject attrgetter_type = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"operator.attrgetter",		/* tp_name */
	sizeof(attrgetterobject),	/* tp_basicsize */
	0,				/* tp_itemsize */
	/* methods */
	(destructor)attrgetter_dealloc,	/* tp_dealloc */
	0,				/* tp_print */
	0,				/* tp_getattr */
	0,				/* tp_setattr */
	0,				/* tp_compare */
	0,				/* tp_repr */
	0,				/* tp_as_number */
	0,				/* tp_as_sequence */
	0,				/* tp_as_mapping */
	0,				/* tp_hash */
	(ternaryfunc)attrgetter_call,	/* tp_call */
	0,				/* tp_str */
	PyObject_GenericGetAttr,	/* tp_getattro */
	0,				/* tp_setattro */
	0,				/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,	/* tp_flags */
	attrgetter_doc,			/* tp_doc */
	(traverseproc)attrgetter_traverse,	/* tp_traverse */
	0,				/* tp_clear */
	0,				/* tp_richcompare */
	0,				/* tp_weaklistoffset */
	0,				/* tp_iter */
	0,				/* tp_iternext */
	0,				/* tp_methods */
	0,				/* tp_members */
	0,				/* tp_getset */
	0,				/* tp_base */
	0,				/* tp_dict */
	0,				/* tp_descr_get */
	0,				/* tp_descr_set */
	0,				/* tp_dictoffset */
	0,				/* tp_init */
	0,				/* tp_alloc */
	attrgetter_new,			/* tp_new */
	0,				/* tp_free */
};


/* methodcaller object **********************************************************/

typedef struct {
	PyObject_HEAD
	PyObject *name;
	PyObject *args;
	PyObject *kwds;
} methodcallerobject;

static PyTypeObject methodcaller_type;

static PyObject *
methodcaller_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
	methodcallerobject *mc;
	PyObject *name, *newargs;

	if (PyTuple_GET_SIZE(args) < 1) {
		PyErr_SetString(PyExc_TypeError, "methodcaller needs at least "
				"one argument, the method name");
		return NULL;
	}

	/* create methodcallerobject structure */
	mc = PyObject_GC_New(methodcallerobject, &methodcaller_type);
	if (mc == NULL) 
		return NULL;	

	newargs = PyTuple_GetSlice(args, 1, PyTuple_GET_SIZE(args));
	if (newargs == NULL) {
		Py_DECREF(mc);
		return NULL;
	}
	mc->args = newargs;

	name = PyTuple_GET_ITEM(args, 0);
	Py_INCREF(name);
	mc->name = name;

	Py_XINCREF(kwds);
	mc->kwds = kwds;

	PyObject_GC_Track(mc);
	return (PyObject *)mc;
}

static void
methodcaller_dealloc(methodcallerobject *mc)
{
	PyObject_GC_UnTrack(mc);
	Py_XDECREF(mc->name);
	Py_XDECREF(mc->args);
	Py_XDECREF(mc->kwds);
	PyObject_GC_Del(mc);
}

static int
methodcaller_traverse(methodcallerobject *mc, visitproc visit, void *arg)
{
	Py_VISIT(mc->args);
	Py_VISIT(mc->kwds);
	return 0;
}

static PyObject *
methodcaller_call(methodcallerobject *mc, PyObject *args, PyObject *kw)
{
	PyObject *method, *obj, *result;

	if (!PyArg_UnpackTuple(args, "methodcaller", 1, 1, &obj))
		return NULL;
	method = PyObject_GetAttr(obj, mc->name);
	if (method == NULL)
		return NULL;
	result = PyObject_Call(method, mc->args, mc->kwds);
	Py_DECREF(method);
	return result;
}

PyDoc_STRVAR(methodcaller_doc,
"methodcaller(name, ...) --> methodcaller object\n\
\n\
Return a callable object that calls the given method on its operand.\n\
After, f = methodcaller('name'), the call f(r) returns r.name().\n\
After, g = methodcaller('name', 'date', foo=1), the call g(r) returns\n\
r.name('date', foo=1).");

static PyTypeObject methodcaller_type = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"operator.methodcaller",	/* tp_name */
	sizeof(methodcallerobject),	/* tp_basicsize */
	0,				/* tp_itemsize */
	/* methods */
	(destructor)methodcaller_dealloc, /* tp_dealloc */
	0,				/* tp_print */
	0,				/* tp_getattr */
	0,				/* tp_setattr */
	0,				/* tp_compare */
	0,				/* tp_repr */
	0,				/* tp_as_number */
	0,				/* tp_as_sequence */
	0,				/* tp_as_mapping */
	0,				/* tp_hash */
	(ternaryfunc)methodcaller_call,	/* tp_call */
	0,				/* tp_str */
	PyObject_GenericGetAttr,	/* tp_getattro */
	0,				/* tp_setattro */
	0,				/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
	methodcaller_doc,			/* tp_doc */
	(traverseproc)methodcaller_traverse,	/* tp_traverse */
	0,				/* tp_clear */
	0,				/* tp_richcompare */
	0,				/* tp_weaklistoffset */
	0,				/* tp_iter */
	0,				/* tp_iternext */
	0,				/* tp_methods */
	0,				/* tp_members */
	0,				/* tp_getset */
	0,				/* tp_base */
	0,				/* tp_dict */
	0,				/* tp_descr_get */
	0,				/* tp_descr_set */
	0,				/* tp_dictoffset */
	0,				/* tp_init */
	0,				/* tp_alloc */
	methodcaller_new,		/* tp_new */
	0,				/* tp_free */
};


/* Initialization function for the module (*must* be called initoperator) */

PyMODINIT_FUNC
initoperator(void)
{
	PyObject *m;
        
	/* Create the module and add the functions */
        m = Py_InitModule4("operator", operator_methods, operator_doc,
		       (PyObject*)NULL, PYTHON_API_VERSION);
	if (m == NULL)
		return;

	if (PyType_Ready(&itemgetter_type) < 0)
		return;
	Py_INCREF(&itemgetter_type);
	PyModule_AddObject(m, "itemgetter", (PyObject *)&itemgetter_type);

	if (PyType_Ready(&attrgetter_type) < 0)
		return;
	Py_INCREF(&attrgetter_type);
	PyModule_AddObject(m, "attrgetter", (PyObject *)&attrgetter_type);

	if (PyType_Ready(&methodcaller_type) < 0)
		return;
	Py_INCREF(&methodcaller_type);
	PyModule_AddObject(m, "methodcaller", (PyObject *)&methodcaller_type);
}