Implement PEP 238 in its (almost) full glory.

This introduces:

- A new operator // that means floor division (the kind of division
  where 1/2 is 0).

- The "future division" statement ("from __future__ import division)
  which changes the meaning of the / operator to implement "true
  division" (where 1/2 is 0.5).

- New overloadable operators __truediv__ and __floordiv__.

- New slots in the PyNumberMethods struct for true and floor division,
  new abstract APIs for them, new opcodes, and so on.

I emphasize that without the future division statement, the semantics
of / will remain unchanged until Python 3.0.

Not yet implemented are warnings (default off) when / is used with int
or long arguments.

This has been on display since 7/31 as SF patch #443474.

Flames to /dev/null.

1 files changed, 30 insertions, 0 deletions

diff --git a/Objects/abstract.c b/Objects/abstract.c
index a0f075f..b646c36 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -565,6 +565,20 @@ PyNumber_Add(PyObject *v, PyObject *w)
 }
 
 PyObject *
+PyNumber_FloorDivide(PyObject *v, PyObject *w)
+{
+	/* XXX tp_flags test */
+	return binary_op(v, w, NB_SLOT(nb_floor_divide), "//");
+}
+
+PyObject *
+PyNumber_TrueDivide(PyObject *v, PyObject *w)
+{
+	/* XXX tp_flags test */
+	return binary_op(v, w, NB_SLOT(nb_true_divide), "/");
+}
+
+PyObject *
 PyNumber_Remainder(PyObject *v, PyObject *w)
 {
 	if (PyString_Check(v))
@@ -631,6 +645,22 @@ INPLACE_BINOP(PyNumber_InPlaceSubtract, nb_inplace_subtract, nb_subtract, "-=")
 INPLACE_BINOP(PyNumber_InPlaceDivide, nb_inplace_divide, nb_divide, "/=")
 
 PyObject *
+PyNumber_InPlaceFloorDivide(PyObject *v, PyObject *w)
+{
+	/* XXX tp_flags test */
+	return binary_iop(v, w, NB_SLOT(nb_inplace_floor_divide),
+			  NB_SLOT(nb_floor_divide), "//=");
+}
+
+PyObject *
+PyNumber_InPlaceTrueDivide(PyObject *v, PyObject *w)
+{
+	/* XXX tp_flags test */
+	return binary_iop(v, w, NB_SLOT(nb_inplace_true_divide),
+			  NB_SLOT(nb_true_divide), "/=");
+}
+
+PyObject *
 PyNumber_InPlaceAdd(PyObject *v, PyObject *w)
 {
 	binaryfunc f = NULL;