Operators like __add__

Modules/operator.c

+static char 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.\n\
+";
+
+/*
+
+     Copyright 
+
+       Copyright 1996 Digital Creations, L.C., 910 Princess Anne
+       Street, Suite 300, Fredericksburg, Virginia 22401 U.S.A. All
+       rights reserved.  Copyright in this software is owned by DCLC,
+       unless otherwise indicated. Permission to use, copy and
+       distribute this software is hereby granted, provided that the
+       above copyright notice appear in all copies and that both that
+       copyright notice and this permission notice appear. Note that
+       any product, process or technology described in this software
+       may be the subject of other Intellectual Property rights
+       reserved by Digital Creations, L.C. and are not licensed
+       hereunder.
+
+     Trademarks 
+
+       Digital Creations & DCLC, are trademarks of Digital Creations, L.C..
+       All other trademarks are owned by their respective companies. 
+
+     No Warranty 
+
+       The software is provided "as is" without warranty of any kind,
+       either express or implied, including, but not limited to, the
+       implied warranties of merchantability, fitness for a particular
+       purpose, or non-infringement. This software could include
+       technical inaccuracies or typographical errors. Changes are
+       periodically made to the software; these changes will be
+       incorporated in new editions of the software. DCLC may make
+       improvements and/or changes in this software at any time
+       without notice.
+
+     Limitation Of Liability 
+
+       In no event will DCLC be liable for direct, indirect, special,
+       incidental, economic, cover, or consequential damages arising
+       out of the use of or inability to use this software even if
+       advised of the possibility of such damages. Some states do not
+       allow the exclusion or limitation of implied warranties or
+       limitation of liability for incidental or consequential
+       damages, so the above limitation or exclusion may not apply to
+       you.
+
+
+    If you have questions regarding this software,
+    contact:
+   
+      Jim Fulton, jim@digicool.com
+      Digital Creations L.C.  
+   
+      (540) 371-6909
+
+    Modifications
+    
+      Renamed and slightly rearranged by Guido van Rossum
+
+*/
+
+#include "Python.h"
+
+#define spam1(OP,AOP) static PyObject *OP(s,a) PyObject *s, *a; { \
+  PyObject *a1; \
+  if(! PyArg_ParseTuple(a,"O",&a1)) return NULL; \
+  return AOP(a1); }
+
+#define spam2(OP,AOP) static PyObject *OP(s,a) PyObject *s, *a; { \
+  PyObject *a1, *a2; \
+  if(! PyArg_ParseTuple(a,"OO",&a1,&a2)) return NULL; \
+  return AOP(a1,a2); }
+
+#define spamoi(OP,AOP) static PyObject *OP(s,a) PyObject *s, *a; { \
+  PyObject *a1; int a2; \
+  if(! PyArg_ParseTuple(a,"Oi",&a1,&a2)) return NULL; \
+  return AOP(a1,a2); }
+
+#define spam2n(OP,AOP) static PyObject *OP(s,a) PyObject *s, *a; { \
+  PyObject *a1, *a2; \
+  if(! PyArg_ParseTuple(a,"OO",&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(s,a) PyObject *s, *a; { \
+  PyObject *a1, *a2, *a3; \
+  if(! PyArg_ParseTuple(a,"OOO",&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(s,a) PyObject *s, *a; { \
+  PyObject *a1; long r; \
+  if(! PyArg_ParseTuple(a,"O",&a1)) return NULL; \
+  if(-1 == (r=AOP(a1))) return NULL; \
+  return PyInt_FromLong(r); }
+
+#define spami2(OP,AOP) static PyObject *OP(s,a) PyObject *s, *a; { \
+  PyObject *a1, *a2; long r; \
+  if(! PyArg_ParseTuple(a,"OO",&a1,&a2)) return NULL; \
+  if(-1 == (r=AOP(a1,a2))) return NULL; \
+  return PyInt_FromLong(r); }
+
+spami(isCallable       , PyCallable_Check)
+spami(isNumberType     , PyNumber_Check)
+spami(truth            , PyObject_IsTrue)
+spam2(__add          , PyNumber_Add)
+spam2(__sub          , PyNumber_Subtract)
+spam2(__mul          , PyNumber_Multiply)
+spam2(__div          , PyNumber_Divide)
+spam2(__mod          , PyNumber_Remainder)
+spam1(__neg          , PyNumber_Negative)
+spam1(__pos          , PyNumber_Positive)
+spam1(__abs          , PyNumber_Absolute)
+spam1(__inv          , PyNumber_Invert)
+spam2(__lshift       , PyNumber_Lshift)
+spam2(__rshift       , PyNumber_Rshift)
+spam2(__and          , PyNumber_And)
+spam2(__xor          , PyNumber_Xor)
+spam2(__or           , PyNumber_Or)
+spami(isSequenceType   , PySequence_Check)
+spam2(__concat       , PySequence_Concat)
+spamoi(__repeat       , PySequence_Repeat)
+spami2(sequenceIncludes, PySequence_In)
+spami2(indexOf         , PySequence_Index)
+spami2(countOf         , PySequence_Count)
+spami(isMappingType    , PyMapping_Check)
+spam2(__getitem      , PyObject_GetItem)
+spam3n(__setitem     , PyObject_SetItem)
+
+static PyObject*
+__getslice(s,a)
+     PyObject *s, *a;
+{
+  PyObject *a1;
+  long a2,a3;
+
+  if(! PyArg_ParseTuple(a,"Oii",&a1,&a2,&a3)) return NULL;
+
+  return PySequence_GetSlice(a1,a2,a3);
+}
+
+static PyObject*
+__setslice(s,a)
+     PyObject *s, *a;
+{
+  PyObject *a1, *a4;
+  long a2,a3;
+
+  if(! PyArg_ParseTuple(a,"OiiO",&a1,&a2,&a3,&a4)) return NULL;
+
+  if(-1 == PySequence_SetSlice(a1,a2,a3,a4)) return NULL;
+
+  Py_INCREF(Py_None);
+  return Py_None;
+}
+
+#undef spam1
+#undef spam2
+#define spam1(OP,DOC) {#OP, OP, 1, #OP "(o) -- " DOC},
+#define spam2(OP,DOC) {#OP, OP, 1, #OP "(a,b) -- " DOC},
+#define spam3(OP,DOC) {#OP, OP, 1, #OP "(a,b,c) -- " DOC},
+
+static struct PyMethodDef operator_methods[] = {
+spam1(isCallable      , "Return 1 if o is callable, and zero otherwise.")
+spam1(isNumberType    , "Return 1 if o has a numeric type, and zero otherwise.")
+spam1(isSequenceType  , "Return 1 if o has a sequence type, and zero otherwise.")
+spam1(truth           , "Return 1 if o is true, and 0 otherwise.")
+spam2(sequenceIncludes, "Return 1 is a includes b, and 0 otherwise.")
+spam2(indexOf         , "Return the index of b in a.")
+spam2(countOf         , "Return the number of times b occurs in a.")
+spam1(isMappingType   , "Return 1 if o has a mapping type, and zero otherwise.")
+
+#undef spam1
+#undef spam2
+#undef spam3
+#define spam1(OP,DOC) {#OP, __ ## OP, 1, #OP "(o) -- " DOC}, \
+            {"__" #OP "__", __ ## OP, 1, #OP "(o) -- " DOC}, 
+#define spam2(OP,DOC) {#OP, __ ## OP, 1, #OP "(a,b) -- " DOC}, \
+            {"__" #OP "__", __ ## OP, 1, #OP "(a,b) -- " DOC}, 
+#define spam3(OP,DOC) {#OP, __ ## OP, 1, #OP "(a,b,c) -- " DOC}, \
+            {"__" #OP "__", __ ## OP, 1, #OP "(a,b,c) -- " DOC}, 
+#define spam4(OP,DOC) {#OP, __ ## OP, 1, #OP "(a,b,c,v) -- " DOC}, \
+            {"__" #OP "__", __ ## OP, 1, #OP "(a,b,c,v) -- " DOC}, 
+
+
+spam2(add         , "Return a + b, for a and b numbers.")
+spam2(sub         , "Return a - b.")
+spam2(mul         , "Return a * b, for a and b numbers.")
+spam2(div         , "Return a / b.")
+spam2(mod         , "Return a % b.")
+spam1(neg         , "Return o negated.")
+spam1(pos         , "Return o positive.")
+spam1(abs         , "Return the absolute value of o.")
+spam1(inv         , "Return the inverse of o.")
+spam2(lshift      , "Return a shifted left by b.")
+spam2(rshift      , "Return a shifted right by b.")
+spam2(and         , "Return the bitwise and of a and b.")
+spam2(xor         , "Return the bitwise exclusive-or of a and b.")
+spam2(or          , "Return the bitwise or of a and b.")
+spam2(concat      , "Return a + b, for a and b sequences.")
+spam2(repeat      , "Return a + b, where a is a sequence, and b is an "
+                        "integer.")
+spam2(getitem     , "Return the value of a at index b.")
+spam3(setitem     , "Set the value of a at b to c.")
+spam2(getslice    , "Return the slice of a from b to c-1.")
+spam4(setslice    , "Set the slice of a from b to c-1 to the sequence, v.")
+	{NULL,		NULL}		/* sentinel */
+
+
+};
+
+
+/* Initialization function for the module (*must* be called initoperator) */
+
+void
+initoperator()
+{
+  PyObject *m, *d;
+  
+  /* Create the module and add the functions */
+  m = Py_InitModule4("operator", operator_methods,
+		     operator_doc,
+		     (PyObject*)NULL,PYTHON_API_VERSION);
+
+  /* Add some symbolic constants to the module */
+  d = PyModule_GetDict(m);
+  PyDict_SetItemString(d, "__version__",PyString_FromString("$Rev$"));
+  
+  /* Check for errors */
+  if (PyErr_Occurred())
+    Py_FatalError("can't initialize module operator");
+}