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classification
Title: svn head compiler fails to spot extended slicing
Type: Stage:
Components: Interpreter Core Versions:
process
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: Nosy List: logistix, mwh, ncoghlan
Priority: normal Keywords:

Created on 2006-03-02 01:20 by mwh, last changed 2022-04-11 14:56 by admin. This issue is now closed.

Messages (5)
msg27641 - (view) Author: Michael Hudson (mwh) (Python committer) Date: 2006-03-02 01:20
This is Python SVN HEAD:

>>> dis.dis(compile("x[::]", '', 'single'))
  1           0 LOAD_NAME                0 (x)
              3 SLICE+0             
              4 PRINT_EXPR          
              5 LOAD_CONST               0 (None)
              8 RETURN_VALUE        

This is Python 2.4:

>>> dis.dis(compile("x[::]", '', 'single'))
  1           0 LOAD_NAME                0 (x)
              3 LOAD_CONST               0 (None)
              6 LOAD_CONST               0 (None)
              9 LOAD_CONST               0 (None)
             12 BUILD_SLICE              3
             15 BINARY_SUBSCR       
             16 PRINT_EXPR          
             17 LOAD_CONST               0 (None)
             20 RETURN_VALUE        
msg27642 - (view) Author: Grant Olson (logistix) Date: 2006-03-05 23:33
Logged In: YES 
user_id=699438

This only happens when you have implicit slice values. 
x[1:2:3] works fine.  I'm finishing up a patch and will post
to sf shortly.
msg27643 - (view) Author: Grant Olson (logistix) Date: 2006-03-10 00:22
Logged In: YES 
user_id=699438

Patch 1446847 Posted.
msg27644 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2006-03-17 13:45
Logged In: YES 
user_id=1038590

Alternate patch that doesn't modify the AST posted as 1452332
msg27645 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2006-03-17 18:04
Logged In: YES 
user_id=1038590

Applied 1452332 to SVN (generates an explicit None reference
for the step when the second colon is present but no
expressions is supplied for the step)
History
Date User Action Args
2022-04-11 14:56:15adminsetgithub: 42963
2006-03-02 01:20:13mwhcreate