*** Python-2.3b1.orig/Python/bltinmodule.c	Fri May  9 10:38:36 2003
--- Python-2.3b1/Python/bltinmodule.c	Fri May  9 14:10:15 2003
***************
*** 13,18 ****
--- 13,36 ----
  #include "unixstuff.h"
  #endif
  
+ /* return 1 if the  object will only be used for iteration. */
+ #include "frameobject.h"
+ #include "opcode.h"
+ int Py_IsIterationContext(void)
+ {
+ 	PyFrameObject *frame = PyThreadState_Get()->frame;        
+ 	if (frame) {
+ 		unsigned char *opcode;
+ 		PyCodeObject* c = frame->f_code;
+ 		_PyCode_GETCODEPTR(c, &opcode);
+ 		/*we are always called by a CALL_FUNCTION opcode (1 arg)*/
+ 		if (*(opcode + frame->f_lasti + 3) ==  GET_ITER) {
+ 			return 1;
+ 		}
+ 	}
+ 	return 0;
+ }
+ 
  /* The default encoding used by the platform file system APIs
     Can remain NULL for all platforms that don't have such a concept
  */
***************
*** 1487,1494 ****
  	long bign;
  	int i, n;
  
- 	PyObject *v;
- 
  	if (PyTuple_Size(args) <= 1) {
  		if (!PyArg_ParseTuple(args,
  				"l;range() requires 1-3 int arguments",
--- 1505,1510 ----
***************
*** 1520,1538 ****
  				"range() result has too many items");
  		return NULL;
  	}
! 	v = PyList_New(n);
! 	if (v == NULL)
! 		return NULL;
! 	for (i = 0; i < n; i++) {
! 		PyObject *w = PyInt_FromLong(ilow);
! 		if (w == NULL) {
! 			Py_DECREF(v);
  			return NULL;
  		}
! 		PyList_SET_ITEM(v, i, w);
! 		ilow += istep;
  	}
- 	return v;
  }
  
  PyDoc_STRVAR(range_doc,
--- 1536,1563 ----
  				"range() result has too many items");
  		return NULL;
  	}
! 
! 	// Avoid the creation of the list object in the really common 
! 	// piece of code "for i in range(N):"
! 	if (Py_IsIterationContext()) {
! 		return PyRangeIter_New(ilow, n, istep);
! 	}
! 	else {
! 		PyObject* v = PyList_New(n);
! 		if (v == NULL) {
  			return NULL;
  		}
! 		for (i = 0; i < n; i++) {
! 			PyObject *w = PyInt_FromLong(ilow);
! 			if (w == NULL) {
! 				Py_DECREF(v);
! 				return NULL;
! 			}
! 			PyList_SET_ITEM(v, i, w);
! 			ilow += istep;
! 		}		
! 		return v;
  	}
  }
  
  PyDoc_STRVAR(range_doc,
*** Python-2.3b1.orig/Objects/rangeobject.c	Fri May  9 10:38:33 2003
--- Python-2.3b1/Objects/rangeobject.c	Fri May  9 14:14:21 2003
***************
*** 226,248 ****
  
  static PyTypeObject Pyrangeiter_Type;
  
! static PyObject *
! range_iter(PyObject *seq)
  {
  	rangeiterobject *it;
  
- 	if (!PyRange_Check(seq)) {
- 		PyErr_BadInternalCall();
- 		return NULL;
- 	}
  	it = PyObject_New(rangeiterobject, &Pyrangeiter_Type);
  	if (it == NULL)
  		return NULL;
  	it->index = 0;
! 	it->start = ((rangeobject *)seq)->start;
! 	it->step = ((rangeobject *)seq)->step;
! 	it->len = ((rangeobject *)seq)->len;
! 	return (PyObject *)it;
  }
  
  static PyObject *
--- 226,256 ----
  
  static PyTypeObject Pyrangeiter_Type;
  
! PyObject *
! PyRangeIter_New(long start, long len, long step)
  {
  	rangeiterobject *it;
  
  	it = PyObject_New(rangeiterobject, &Pyrangeiter_Type);
  	if (it == NULL)
  		return NULL;
  	it->index = 0;
! 	it->start = start;
! 	it->step = step;
! 	it->len = len;
! 	return (PyObject *)it;   
! }
! 
! static PyObject *
! range_iter(PyObject *seq)
! {
! 	if (!PyRange_Check(seq)) {
! 		PyErr_BadInternalCall();
! 		return NULL;
! 	}
! 	return PyRangeIter_New(((rangeobject *)seq)->start,
! 			       ((rangeobject *)seq)->len,
! 			       ((rangeobject *)seq)->step);
  }
  
  static PyObject *
*** Python-2.3b1.orig/Include/rangeobject.h	Fri May  9 10:38:15 2003
--- Python-2.3b1/Include/rangeobject.h	Fri May  9 10:40:18 2003
***************
*** 20,25 ****
--- 20,26 ----
  #define PyRange_Check(op) ((op)->ob_type == &PyRange_Type)
  
  PyAPI_FUNC(PyObject *) PyRange_New(long, long, long, int);
+ PyAPI_FUNC(PyObject *) PyRangeIter_New(long, long, long);
  
  #ifdef __cplusplus
  }
*** Python-2.3b1.orig/Lib/test/test_builtin.py	Fri May  9 10:38:20 2003
--- Python-2.3b1/Lib/test/test_builtin.py	Fri May  9 12:16:10 2003
***************
*** 927,932 ****
--- 927,945 ----
          self.assertEqual(range(1, 10, 3), [1, 4, 7])
          self.assertEqual(range(5, -5, -3), [5, 2, -1, -4])
  
+         # Check special case optimization
+         def for_range(*args):
+             r = []
+             for i in range(*args):
+ 		r.append(i)
+             return r
+         self.assertEqual(for_range(3), [0, 1, 2])
+         self.assertEqual(for_range(1, 5), [1, 2, 3, 4])
+         self.assertEqual(for_range(0), [])
+         self.assertEqual(for_range(-3), [])
+         self.assertEqual(for_range(1, 10, 3), [1, 4, 7])
+         self.assertEqual(for_range(5, -5, -3), [5, 2, -1, -4])
+ 
          # Now test range() with longs
          self.assertEqual(range(-2**100), [])
          self.assertEqual(range(0, -2**100), [])