[Python-checkins] CVS: python/dist/src/Grammar Grammar,1.43,1.44

[Guido van Rossum]

Update of /cvsroot/python/python/dist/src/Grammar
In directory usw-pr-cvs1:/tmp/cvs-serv23513/Grammar

Modified Files:
	Grammar 
Log Message:
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.



Index: Grammar
===================================================================
RCS file: /cvsroot/python/python/dist/src/Grammar/Grammar,v
retrieving revision 1.43
retrieving revision 1.44
diff -C2 -d -r1.43 -r1.44
*** Grammar	2001/06/18 22:08:13	1.43
--- Grammar	2001/08/08 05:00:17	1.44
***************
*** 39,43 ****
  small_stmt: expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt | exec_stmt | assert_stmt
  expr_stmt: testlist (augassign testlist | ('=' testlist)*)
! augassign: '+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' | '<<=' | '>>=' | '**='
  # For normal assignments, additional restrictions enforced by the interpreter
  print_stmt: 'print' ( [ test (',' test)* [','] ] | '>>' test [ (',' test)+ [','] ] )
--- 39,43 ----
  small_stmt: expr_stmt | print_stmt  | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt | exec_stmt | assert_stmt
  expr_stmt: testlist (augassign testlist | ('=' testlist)*)
! augassign: '+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' | '<<=' | '>>=' | '**=' | '//='
  # For normal assignments, additional restrictions enforced by the interpreter
  print_stmt: 'print' ( [ test (',' test)* [','] ] | '>>' test [ (',' test)+ [','] ] )
***************
*** 78,82 ****
  shift_expr: arith_expr (('<<'|'>>') arith_expr)*
  arith_expr: term (('+'|'-') term)*
! term: factor (('*'|'/'|'%') factor)*
  factor: ('+'|'-'|'~') factor | power
  power: atom trailer* ('**' factor)*
--- 78,82 ----
  shift_expr: arith_expr (('<<'|'>>') arith_expr)*
  arith_expr: term (('+'|'-') term)*
! term: factor (('*'|'/'|'%'|'//') factor)*
  factor: ('+'|'-'|'~') factor | power
  power: atom trailer* ('**' factor)*