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, 13 insertions, 0 deletions

diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index b783e80..2397969 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -80,6 +80,8 @@ char *_PyParser_TokenNames[] = {
 	"LEFTSHIFTEQUAL",
 	"RIGHTSHIFTEQUAL",
 	"DOUBLESTAREQUAL",
+	"DOUBLESLASH",
+	"DOUBLESLASHEQUAL",
 	/* This table must match the #defines in token.h! */
 	"OP",
 	"<ERRORTOKEN>",
@@ -408,6 +410,7 @@ PyToken_TwoChars(int c1, int c2)
 		break;
 	case '/':
 		switch (c2) {
+		case '/':	return DOUBLESLASH;
 		case '=':	return SLASHEQUAL;
 		}
 		break;
@@ -469,6 +472,16 @@ PyToken_ThreeChars(int c1, int c2, int c3)
 			break;
 		}
 		break;
+	case '/':
+		switch (c2) {
+		case '/':
+			switch (c3) {
+			case '=':
+				return DOUBLESLASHEQUAL;
+			}
+			break;
+		}
+		break;
 	}
 	return OP;
 }